geoinformatics 2006 vol07

INTERGEO 2006 Conference anReport about Recent Trends in the GIS sector INTERGEO

Knowledge and Action for Planet EarthThe INTERGEO facilitates the contact betweensuppliers and clients. It represents a uniquecombination of international and interdisci-plinary structure. As Jack Dangermond, ESRIspresident, who visited the INTERGEO for thefirst time this year comments: The fair is animportant platform. I can only call on organisa-tions worldwide to participate in INTERGEO,since this exhibition is the prime marketplacefor the very latest happenings and develop-ments in the field of GIS. The congress trade fair is themed Knowledgeand action for planet Earth. Information andparticularly geoinformation provides a sourcefor knowledge that can be extracted by gather-ing, processing and visualising geodata to

assist in decision making and acting for thesociety and for planet Earth. The tools thatmediate between information, knowledge andaction are Geographical Information Systems(GIS). This report will point out recent trendsin the GIS sector observed on the INTERGEO2006. While strolling around in the three big exhibi-tion halls one can try his luck at Bentleyswheel of fortune, take over the steering-wheelin Trimbles Formula one racing car simulation,see the picture on page 7, inspect the micro-light at the booth of the University of Munichor relax in one of the canvas chairs at the arti-ficial beach of the Open-Souce Park. Whilstmany INTERGEO visitors were attracted bythese superficial eye-catchers to make them

having a closer look at the companies products,many other developments and trends could beobserved during a walk over the exhibitioncompound.

The Rise of Earth ExplorersThe boost of Earth Explorers like Google Earthattract the attention of millions of users world-wide. Although Google and Microsoft are noinsiders in the GIS world, their developmentsseem to push the whole GIS industry and putGIS on the stage for a worldwide audience. Iexpected to see this influence on the INTER-GEO. In fact some companies such as Bentleyand research institutions like the Runder TischGIS e.V. presented technical solutions todynamically link web map services with theGoogle Earth client software to visualise andquery geodatasets via the Internet. GoogleEarth provides a convenient client which isavailable for free and is used by millions ofpeople already. Nevertheless I could notobserve many other GIS application workingwith Earth Explorers. Probably there still istoo less time for GIS companies and they tryto slowly approach the integration of thoseEarth Explorers in their own web-GIS solutions.Nevertheless you can see the boost of freeweb-map clients and 3D earth navigation thathas been activated by the Earth Explorers,says Daniel fele, GIS researcher at TUMnchen, the Technical University of Munich.Autodesks MapGuide, Intergraphs WMS-Viewerand the ArcExplorer from ESRI are just some ofthem. Definitely they already existed beforeGoogle Earth came up, but now the GIS com-panies are working hard to make them better.

Location Based ServicesA really smart development could be found atthe booth of NAVXS. They offer a Java applica-tion for mobile phones that can locate thephone and send this information to a centralserver. The location is used to request maps

Oct./Nov. 20066

Conferences & Meet ings

INTERGEO is Europes biggest conference and trade fair for geodesy, geoinformation and land management. With more than

17,000 visitors and delegates from more than 80 countries the INTERGEO and the FIG World Conference 2006 both took place

together this year - is the largest meeting point for the industry sectors geodesy, geoinformation and land management in Europe

and beyond. This years INTERGEO took place in the international trade-fair center in Munich from October 10th to 12th 2006.

By Florian Fischer

INTERGEO, prime marketplacefor the very latest happeningsand developments in the field of GIS.

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from Earth Explorers like Google Maps, MSMaps, Yahoo Maps and Ask Maps and sendingthem to the mobile phone. It is a fast andpromising application usable for many locationbased services. The presented application is afriend finder where one can locate himself andhis position will be shown on all of his friendsmobile phones. The claim of fame is that thisservice is for free. The only requirements are aGPS-enabled mobile phone and a mobileInternet connection. The combination of webmapping services and mobile phones concealsa still fallow potential. As Lars Mohr, scientistat the University of Munich, points out:Geodata is becoming increasingly popularthanks to attractive applications such as inter-net-based map services and ChristophLangewisch from NAVXS adds: One future ofthese services is their fusion with mobiledevices and position finding.

Geoportal Solutions A geoportal is the concept of having a mainaccess point to a collection of geodata andservices that are offered by an institution or aprivate company. All services and data areavailable via the Internet. A geoportal providesthe user with tools for retrieving metadata,searching for geodata and visualising it viaweb map clients. Geoportals can give accessto company-wide and region-wide geodata.National Geodata Infrastructures (GDI) arebased on various connected geoportals thatrepresent the national geodata stock. Geodatainfrastructures consist of geodata, networks,services and norms for accessing the data.Some GDI projects were present at the INTER-GEO, and the share of GIS companies who sellcomplete GIS-portal packages is increasingagain this year. This support and the accep-tance of many customers is one more step tothe ambitious aim of establishing a EuropeanSpatial Data Infrastructure that covers a broadrange of area-wide geodata and geoprocessingservices available by the Internet for every cus-tomer.

3D Maps The future of maps thats what RSS RemoteSensing Solutions GmbH, promises with itsphotorealistic 3D city maps and landscapemaps. Many companies such as Viewtec and3D Geo Gmbh offer these 3D maps and appli-cations to visualise them. Even the possibility

organised an ephemeral GIS information eventin Munichs football stadium on the 11th ofOctober. During lectures, workshops, extensivecatering and a panel discussion all participantscould catch up with software products anduser cases.

ConclusionAll in all the INTERGEO 2006 offers goodinsight into the dynamics of the GIS market.There is a strong focus on web based serviceswhich will support the construction of regional,national and international Spatial DataInfrastructures. The geo web-services will con-tribute to the development of mobile servicescombined with the use of Global NavigationSatellite Systems for positioning like theupcoming Galileo. The hype about EarthExplorers starts to fade away a bit and the GISsector is adopting their most popular conceptslike 3D landscapes and visualisation of geoda-ta on the virtual globe. I am already lookingforward to INTERGEO 2007 that will take placein Leipzig. But now after a three-days stimulussatiation I better have a look outside again ortake INTERGEOs most popular give-away, theESRI folding chair, and have a rest somewherein the exhibition halls. This is in a way amobile service, too.

Florian Fischer ([email protected]) is

a contributing editor of GeoInformatics.

to include other geodatasets sometimes exit-sts in their products. A better look thanGoogle Earth promises Intermap and theykeep their promise. Googles Earth Viewerseems to have fired this segment of the GIS-market as previous INTERGEO trade fairs havenever shown so many 3D landscape viewers.

Open Source ProductsAt INTERGEO 2006 the first Open Source Parkhas been established by the Open SourceGeospatial Foundation (OSGeo). It has beensomewhat an oasis of the fair wit hits woodenbooths and the coffee lounge where one couldlisten to presentations about projects andsolutions developed by the international freesoftware community. The focus of the lectureshas been on established software packageslike PostGIS, UMN MapServer or Mapbenderand their field of application as well as securi-ty aspects and new applications.

Microsoft, Google and IntergraphWhile their applications have an enormousimpact on the dynamics of the GIS sector itseems quite curious that neither Microsoft norGoogle had a booth on this years INTERGEO.It probably shows the dissentient attitudetowards the creation of value out of geodataand geo-processing. As their business modelfocuses on location based advertisement theearth explorers are just a vehicle and not theproduct itself. Except for some external boothswith small Intergraph presence Intergraph wasabsent. In fact its not that astonishing as they

Oct./Nov. 2006Latest News? Visit www.geoinformatics.com 7

Conferences & Meet ings

n d Trade FairO 2006

Trimbles Formula one racing car simulation.

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Delays and DecisionsGNSS Update

During the last few months it was shown that operationalising or modernizing a satel-

lite navigation system is more difficult than most of us have been led to believe by

the respective governments. With the exception of EGNOS, which finally reached the

operational stage, there is much news of delays and outages. Still most governments

remain positive about the time schedules involved.

By Huibert-Jan Lekkerkerk

GalileoLaunch delay for GIOVE-BIn September it became known that thelaunch of GIOVE-B is delayed as a result ofproblems encountered during testing. Thelaunch was postponed earlier as a result ofthe success of GIOVE-A. Since the successfullaunch of GIOVE-A meant that a quick claim onthe Galileo frequencies was possible, therewas no need for an early launch of GIOVE-B.The launch was then postponed to autumn2006, but is now postponed again to spring2007. According to a spokesman from theGalileo Joint Undertaking the delay will haveno effect on the overall Galileo schedule.

Galileo and KoreaAn agreement between the European Unionand Korea was signed in September. Theagreement, which was signed in Finland, willmake the exchange of satellite navigation

knowledge between Korea and Europe possible.

GLONASSThe operational status of GLONASS is still pre-carious. In previous updates I already men-tioned the limited amount of operational satel-lites. During September a total of six satellitesbecame unusable. For the moment these aresaid to be temporarily switched off, butregarding the age of most of these satellitesthere is a good chance that they will stayunusable. At the moment of writing only 10satellites out of a minimum configuration of 18are operational.

GPSEven though in general the GPS satellites arelasting longer than the GLONASS satellites,they do not live forever. This became clearon the 28th of August when three satellitesbecame unhealthy at the same time. As aresult users experienced configurations thatwere below the standards set over the lastfew years. A positive aspect is that more slotsare now available for the newer types ofsatellites such as the block IIR-M type.On the 25th of September the second so-called GPS block IIR-M satellite was launchedfrom Cape Canaveral. This is exactly a year tothe day of the launch of the first block IIR-Msatellite. It is believed by some that this longinterval between launches shows that the GPSmodernization program is already runningbehind schedule. However, the American gov-ernment still sticks to the original scheme, butthe reality of this is questioned more andmore by positioning specialists.slots are now available for the newer types ofsatellites such as the block IIR-M type.On the 25th of September the second so-

called GPS block IIR-M satellite was launchedfrom Cape Canaveral. This is exactly a year tothe day of the launch of the first block IIR-Msatellite. It is believed by some that this longinterval between launches shows that the GPSmodernization program is already runningbehind schedule. However, the American gov-ernment still sticks to theoriginal scheme, but the reality of this isquestioned more and more by positioningspecialists.

EGNOSRecently it became known that EGNOS signals are available on all three EGNOS satel-lites (Indian Ocean Region West; AtlanticOcean Region and Artemis). This shouldimprove the coverage over Europe vastly. Allsatellites now broadcast the so-called MT 0/2signal which is 100 per cent compatible withthe WAAS signal and can as such be used by all WAAS / EGNOS compatible receivers. The next step is for themember states to decide on whether or notswitching to the so-called full open service thatshould guarantee full availability and reliabilityof the original EGNOS specification. This how-ever is more a political than a technical issue.

Huibert-Jan Lekkerkerk

([email protected]) is a freelance

writer and trainer in the fields of positioning and

hydrography.

Art ic le

Launch of the first block IIR-M GPS satellite on 26September 2006 (source: www.arikah.net).

GPS Block IIR-M satellite during construction (source: www.lockheedmartin.com).

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Magellan Bridges Gap Betwee User Friendliness and Compactness Important

In the previous issue of GeoInformatics we published an article on the take-over of Thales Navigation by Shah Capital Partners

(SCP). The official launch of the new name Magellan took place at INTERGEO in October. GIS-Magazine and GeoInformatics held

interviews with Bas Verbeek, Sales manager Land Survey & GIS Benelux, and VP & General Manager Magellan Professional Franois

Ereau. This article is a compilation of what these gentlemen said.

By Remco Takken and Sonja de Bruijn

Core BusinessIn July the Thales Group said goodbye to thenavigation division, a decision which wasmade after a thorough revision of the Thalesportfolio. This made evident that the Defence,Aerospace and Security departments werecore business. Verbeek: Car navigation isreally booming but this is not core to Thalesbusiness. So they decided that the companycould expand more rapidly under a morefocused sharehold. Thats when SCP cameinto view.

Lately there has been quite a lot of criticismregarding take-overs by investment compa-nies, the main fear being that successfulcompanies are simply stripped and soldagain. According to Magellan however SCP isan investment company that is helping com-panies on a long-term basis and with a focuson technology corporations. Verbeek: In factthe take-over is neither strange nor frighten-ing. It provides us with the ability to growwith the financial means and the operationalexpertise of SCP. According to Ereau the

product strategy will still be determined byMagellan, while the operational structure,logistics and implementation of the productscan be enhanced with the expertise SCPbrings. The company will be even moredynamic and customers will notice this bymore frequent product releases.

Magellan ProfessionalMagellan was already a well-establishedbrand of Thales Navigation for the consumermarket. The American company with that

Oct./Nov. 200610

Interv iew

It was hard to miss out the new company name Magellan at INTERGEO.

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name belonged to the first commercial GPSdevelopers in the eighties, claiming to bethe first in the market. From 1997, after amerge with Ashtech, the company calleditself Magellan Corporation. Meanwhile anumber of companies amalgamated underthe name of Dassault Sercel NP, the last twoletters standing for Navigation Positioning.The name Thales Navigation came about in2001, when Thales Group acquired theAmerican Magellan Corporation and mergedit with DSNP and MLR in Europe. In fact , wehave been making use of the name Magellanfor years, but only as a result of the acquisi-tion is it now also the company name. Todistinguish between consumer and profes-sional markets the professional products arenow sold under the name MagellanProfessional, says Verbeek.

Consumer FocusWhat distinguishes Magellan from the others is the long experience with consumerproducts. Verbeek: These are typical con-sumer products like car navigation, hand-held GPS and tools for outdoor sports likegeo caching. On the professional side thereis RTK-GPS and MobileMapper CE: a PDAwith integrated GPS. We are combining thetechnologies of the consumer and profes-sional products to improve and make further developments. I think we are the only one in the market doing it this way.The advantages of good consumer electron-ics are user friendliness and compactness.The professional user will demand more from company security. A device like that has to be both water resistant and shockproof. Users that are in the field or aredredging while the battery is running emptyneed to be sure they can start workingagain in very short time. User friendlinessis an important aspect with professionalproducts as well. Besides this not only high-ly educated people are using these devicesanymore. A GPS needs to be simple andclear.The complexity of the system needs to be hidden from the customer, is Ereausview. In practical use customers will experi-ence a user interface that is easier to use.There is a large color-lit screen and Promark3 for example involves only three screens to run a full survey job

typical problems: delay and coverage.Still the question is whether radio receptioncan be successful in future. Verbeek says tothis: We invested eight years in Long RangeKinematic (LRK) stations, especially in knowl-edge and technology. And it is a technologythat has proven itself worldwide. We wont letthis go theres too much benefit for the cus-tomer.

GLONASS - Galileo Current GPS devices often make it possibleto receive European Galileo as well asRussian GLONASS signals besides theAmerican GPS signals. Verbeek confirms thistrend: Right now, this is a marketing game.Competitors have been quick to play at it,and we would come to it but only when thebenefit to the customer does outweigh thecost.. GPS is good enough for now but wekeep a close eye on the technology. Ashtech,one of the companies we are originatingfrom, launched the first geodetic GPS-GLONASS RTK receiver in December 1997.Back then the Russian constellation wascomplete, it was of real use, but now it hasdeteriorated. At the moment ten satellitescan be used, which results in two to threesatellites for extra use. However GLONASSand Galileo are just virtual satellites rightnow.It is a matter of time, but apart from thisMagellan remains hesitant. Verbeek makes acomparison with the megapixels in digitalphotography: It is said that more megapix-els means better pictures, but naturally thisis not the case. With a larger number ofsatellites in a disadvantageous position therewill still be no better result. Besides thenumber of signals the quality remains impor-tant as well. Under trees the user will noticethat all signals are evenly disturbed. We areready with these technologies today, butthere needs to be a further value beforeMagellan will bring these technologies tomarket.

Remco Takken ([email protected]) is a

contributing editor of GeoInformatics.

Sonja de Bruijn ([email protected])

is editorial manager of GeoInformatics.

Surf to www.magellanGPS.com for additional

information on Magellan Navigation and products.

Business Partnering and OpennessAlthough Magellan develops software in itsconsumer business, it does not develop soft-ware specifically for MobileMapper CE.Verbeek indicates what the core quality ofMagellan is: We are good at GPS, and thesoftware for the markets MobileMapper CEserves may be done by people experiencedin those vertical markets. We have partneredwith several suppliers of custom made appli-cations. Some examples are Alterra, ESRI andIT Works. Standard functionality is notalways tailored to the user. TurboVeg orVMCE are quite specific applications. Alterraprovides software applications in the field ofecology, like flora and fauna, IT Works hasproducts for soil researchers. The sales manager Land Survey & GISBenelux continues: We are fully aimed atGPS. This means we are not restricted to alimited choice of total stations. This is whywe have an open view towards other partiesdeveloping software for seamless connec-tions with any total stations available. Anexample of this is our Fast Survey software.ADW Software, the company behindPythagoras CAD + GIS, has also a mobileapplication for pen computers in the field.With this device a user can control theMagellan GPS as well as any total stationavailable in the market.

Radio Reception LRK NetworkMagellan is also aiming at another kind ofopenness: when working on centimetre levelone is dependent on correction networks.Verbeek claims: We are one of the few com-panies in this market connecting to everything:commercial networks on GSM and GPRS tech-nology but also real radio correction stations.The Z-Max can handle both radio andGSM/GPRS.According to Verbeek RTK is a better system inspite of a few small limitations. The questionis of course why GSM is so popular nowadays.Verbeek: If you want to cover an entire coun-try the obvious choice is GSM. The limitedreach by radio is regarded as an importantdisadvantage. However Magellan is quite expe-rienced in the maritime sector, our reach isforty kilometres and more by radio. In manycases this is wide enough. For certain usesGSM is expensive. In a technical perspectiveradio is better, since GSM networks have their


Interv iew

e n Consumer and Professional

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Lewis and Clark Bicentennial Two Hundred Years of the Historic Trail Through the Ame

This autumn is a closing time of a three year period of commemorative activities in the USA to revive the memory of the times 200

years ago, when two explorers Meriwether Lewis and William Clark leading the Corps of Discovery explored, surveyed and mapped

then unknown lands between the Mississippi and the Pacific coast. This is an excellent one-time opportunity for the readers of

GeoInformatics to take a short voyage along the trail of this epic story and learn of the influence of a single map on the last two

centuries of history of the USA and its nations.

By Joc Triglav

MythsAt the end of the 18th century the westernpart of North American continent was still abig unknown for the white population ofNorth America. This offered fertile groundsfor numerous myths, which largely definedthis uncharted West. Among the most widelyheld myths and hopes was the existence ofthe so-called Northwest Passage, a river orseries of connected rivers that would crossthe western mountains and reach the PacificOcean, which would have open the wealth ofNorth America and allowed more direct com-merce with the nations across the PacificOcean.

Thomas JeffersonAmong those who supported the idea ofexploration of the western part of the conti-

nent with great perseverance and enthusi-asm was Thomas Jefferson, the principalauthor of the Declaration of Independence in1776. He took the oath of office as the thirdPresident of the United States on March 4,1801. Becoming a president, Jefferson wasfinally in position to make his ideas ofexploring the West true. With this in mind heemployed Captain Meriwether Lewis, hischildhood neighbour from Virginia, as hispersonal secretary.

At that time the American nation counted 5.3million people within its boundaries ofAtlantic Ocean to the east and of theMississippi river to the west, of the GreatLakes to the north and almost to the Gulf ofMexico in the south. Two thirds of the popu-lation then lived within 50 miles of the

Atlantic coast. But Jefferson was convincedthat the United States had the potential tobecome a powerful nation, if it could add thearea west of the Mississippi to its territory. At that time, when for instance only fourroads crossed the Appalachian Mountains toconnect the Atlantic coast and the lands bythe Mississippi, it was impossible to get any-thing from the Mississippi to the Atlanticseaboard in fewer than six weeks. Thereforepeople were sceptical that one nation couldgovern an entire continent, seeing severalnatural and mental barriers to westward

Oct./Nov. 200612

Art ic le

Portraits of Meriwether Lewis (1774-1809) and William Clark (1770-1838) were painted at the peak oftheir fame by Charles Willson Peale in the years 1807-08 for the portrait gallery of great men of theearly republic. (Source: http://www.lewisandclarkexhibit.org)

Thomas Jefferson (1743-1826), the third American president in the period of 1801-1809, was the initiatorand the inspirational leader of the Lewis and Clarkexpedition. As the son of an active surveyor, ThomasJefferson was exposed to the world of mapping andcharting at an early age. Although Jefferson chose law as his profession, in 1773 he briefly considered acareer as a surveyor. Many of his thoughts were devoted to the American West and the possibilities toextend the US political and economic power to thePacific coast. (Source: www.lewisandclarkexhibit.org)

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economical and political expansion. Also, many people along the Mississippi feltthey had found their own national interestsalong the water routes, following the Ohioand Mississippi river system as a source ofcommerce down to the Gulf of Mexicoinstead of going east to the Atlantic coast.They viewed themselves as the core of anindependent nation and thus posed a risk ofsecession from the United States. ThereforeJefferson was determined to obtain the vitaltrading port of New Orleans for the United

Mississippi, consisting of ten to twelve manlead by an intelligent officer, who mightexplore the whole line, even to the WesternOcean. Of course, Jefferson already had hisskilled personal secretary Lewis in mind asthe exploration mission leader. The goals ofthe mission were described as scientific,allowing the fulfilment of economic andpolitical goals at a later stage. Jeffersonwrote in his letter that The river Missouriand the Indians inhabiting it, are not as wellknown as is rendered desirable by their con-nection with the Mississippi, and conse-quently with us Jefferson was well knownas a scholar, but his plans for the explo-ration of the great new areas beyondMississippi were as much commercial andpolitical as they were scientific, because thecommercial growth in the west was a key togain political power in this vast region.

The political situation in that time didntwork in favour of Jeffersons proposal.Unknown lands beyond Mississippi wereclaimed by France and Britain and the south-west was in Spanish hands. Across theMississippi was the large Louisiana Territory,which was administered by Spanish officialson behalf of France. Therefore to make hisproposal to Congress more convincibleJefferson minimized military risks and empha-sized commercial gains. Also to make thetemptation even higher he asked Congressfor only $2,500 to fund the expedition (atthe end the actual costs were almost 16times higher). His tactics proved successfuland it was no surprise when on February 28,1803, Congress approved Jeffersons proposal.

Louisiana PurchaseWith Congress approval the important firststep to the exploration of the West wasmade. However, only two months later anagreement with France was made, whichtotally transformed the purpose of the

States, in part to prevent the West frombreaking away and in part because therereally was the right time to act. Namely, inthat time Britain, France and Spain alsosought to control the Wests destiny but stillknew little about the region.

Confidential LetterAs the president of the USA, Jefferson sent aconfidential letter to Congress on January 18,1803 with a proposal of a military explo-ration mission to the lands west of


Art ic le

Part Ie rican Northwest

A silver medal with the president Thomas Jefferson on one side and the motive of peace and friendship on theother side. The medals were made in three sizes and were presented as gifts to the Indian chiefs, based on theirimportance by the judgement of Lewis and Clark. The medals were often a reason for quarrels and rivalry in and between the tribes, ruining the established hierarchy where it existed or imposing it, where none existed.(Source: www.loc.gov/exhibits/lewisandclark)

Chronological presentation of territorial growth ofthe USA in the 19th century. In connection to theLewis and Clark expedition story the territories ofLouisiana and Oregon are most important. In bluecolour is the Louisiana Territory, which the USAbought from France in 1803. In violet in the northwestis the Oregon Territory, where the USA established its title in 1846. The map also shows the present borders of the federal states and the years of theirestablishing. (Source: www.lib.utexas.edu/maps)

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expedition from a mission through foreign territory into a bold surveyof American-owned land. Much more importantly, the agreementchanged the history of the USA. It all started with Jeffersons bid to buy New Orleans from France as avital port and trading centre for the future development of the USA.During the negotiations Napoleon Bonaparte surprised the world withthe announcement, offering the USA not only New Orleans but theentire Louisiana Territory measuring 820,000 square miles (2,123,000square kilometres) for a price of $ 15 million. Of course, there wasmore than only generosity in Napoleons dramatic offer. Though Franceheld title to Louisiana it couldnt enforce it in reality and Napoleonknew that the Americans would take over the area eventually. Also,France and the USA shared England as their common rival. The treaty of Louisiana Purchase was signed on April 30, 1803 and thesize of the USA was doubled. The Louisiana Purchase was publiclyannounced on July 3, just before Independence Day and also just twodays before Meriwether Lewis left Washington, D.C., for Pittsburgh to


Art ic le

Jefferson was known for his love of precision instruments and Euclidean geometry.He was convinced that measurement and mathematics can reveal the very architec-ture of the universe and that nature's laws are so regular and reasonable that onlyrational inquiry and empirical methods were needed to discover them. Following hisbelief he recommended Lewis to take a theodolite like this, manufactured by thefamed English instrument maker Jesse Ramsden. Theodolite measured precisely bothhorizontal and vertical angles, thus replacing both a surveyor's compass and a sex-tant in surveying and measuring latitude and longitude. In spite of Jefferson'senthusiasm Lewis decided not to take this delicate instrument to the rough environ-ment of the West. (Source: www.lewisandclarkexhibit.org)

The surveyor's compass, also called a circumferentor, was used not only to find northbut also to determine horizontal angles by measuring magnetic azimuths. It hasalso been employed in taking the traverse of the rivers. Invented around 1696, a sur-veyor's compass differs from a hand compass in two ways. First, it includes a sighteither two bars with narrow slits or a tubethrough which the target isobserved. A surveyor's compass is mounted on a pole or tripod to provide a steadybase. Second, because the reading is taken from the back of the needle (rather thanfrom above, as with a hand compass), the positions of east and west are reversed. (Source: www.lewisandclarkexhibit.org)

Measuring and Mapping the West

During their advancement to the West the captains Lewis andClark were performing measurements thoroughly and with greatprofessional care, drawing maps and writing journal reports on adaily basis. Every significant natural feature has got its name,which possibly closely reminded of its characteristic. More impor-tant places have got their names of the important men of theUnited States. Of course, many names were given using the namesof the expedition members, who have gradually got their rivers,creeks, hills or valleys as well as did many of their beloved rela-tives back home. Many of these names can still be found on thepresent-day maps of the USA.

Lewis and Clark used two techniques to map the land along theirtrail: celestial navigation and dead reckoning. Lewis used celestialnavigation to find the expeditions global location of latitude andlongitude. He had to measure his position in relation to the sun,moon or stars. Latitude was the arc distance north of the equatorand it was the easiest to find. Theoretically, all he had to do wasmeasure the height of the sun at noon and then correct it for thetilt of the earth and other factors. For these measurements, heused a sextant or octant, designed for measuring vertical angles.Longitude was the arc distance west of the prime meridian atGreenwich, England, and it was harder to measure. Timekeepingwas the key. Since the Earth rotates at a steady pace, theoreticallyall he had to do was measure the time difference betweenGreenwich and his current position to work out the distance. Buteven with his exquisitely accurate chronometer, Lewis could not besure of the Greenwich Time unless he observed a celestial eventthat had been predicted for Greenwich and measured the exacttime it took place at his current position. For this purpose Lewishad a book of tables that predicted the Greenwich times for vari-ous celestial events.

Clark used an older method to find his location in relation towhere he had been the day before, which was less high-tech thancelestial navigation. The method is called dead reckoning, wherethe key is good record keeping. Each day as the travelled, Clarkwrote down when they changed direction and how far they trav-elled on each bearing, using no more than a compass and awatch. To find the speed of the boat, he used a log line and reel.After a few days, he would transfer his readings onto a gridworkmap on which each square line represented a set distance. A jour-nal notation of 3 miles N 30 W became a line on the map, laidout with a protractor and ruler. During the winters, Clark assem-bled all his route maps and transferred the information onto amaster map, reducing the scale with his drafting instruments.

The three maps of the West Clark made from 1805 to 1814 showhis evolving perceptions of the West. The changes in his maps didnot just show geographical knowledge-they also had political mes-sages. His first map was a blend of Indian information and hisown observations. But in his later maps, the Indian habitation ofthe land was gradually left out and Euro-American informationtook its place.

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Interv iew

begin purchasing supplies and hiring men forthe expedition.

Preparing for the ExpeditionIn 1803, the void on the maps of the landswest of Mississippi was almost complete andwas often filled with the details equally ficti-tious as were the myths of the West. Onething was sure though. Not even the bestminds in the world could fill the void with-out previously walking the vast lands, takingmeasurements and putting as many as pos-sible details regarding the topography, peo-ple, flora and fauna on the map. Obviously, an expedition with such goalswas facing an enormous task. Therefore,Albert Gallatin, Jeffersons secretary of financeand a known map collector, was ordered tomake a special map of North America withall then known data between the Mississippiand the Pacific coast. The map included vari-ous data sources like those from AndrewEllicot for the waters of Ohio, from JamesCook and George Vancouver for the Pacificcoast, from Aaron Arrowsmith and Alexander

Mackenzie for the Missouri river up to itsGreat Bend to the west. The map was made in March 1803 by a military cartographer Nicholas King. On theentire map were only three details with theexactly known location geographical posi-tion of the mouth of the Columbia, of St.Louis and some details of the lower part ofthe Missouri river. The map included a thinestimation of the Rockies and the approxi-mate course of the Columbia.

To lead such an expedition it was essentialto get all available knowledge. For this rea-son Jefferson sent Lewis to Philadelphia tothe leading scientists of that time to learnabout celestial navigation, botany, zoologyand medicine. There Lewis purchased alsothe measurement equipment for the expedi-tion, comprising of surveyors compass, handcompass, quadrants, telescope, thermome-ters, two sextants, a set of plotting instru-ments and a precise chronometer. Lewisinvited his former army comrade CaptainWilliam Clark to join him in the expedition

as a co-leader and Clark accepted his invitation.

Jefferson gave Lewis several pages of specificinstructions about what information to col-lect during the expedition. Of special interestto Jefferson were answers to questions likewhat were the Indians like and what weretheir languages, customs and medical habits?Also the details of the plant and animal life,the minerals and the mountains were veryimportant to observe and report. Anotherimportant matter was information on thepossibilities for trade. Jefferson also gaverecommendations on the procedure of com-municating with Indians and underlined thehigh importance of protecting lives. Lewisalso received from Jefferson his signed letterof confidence, stating that the USA wouldreimburse anyone for any goods or servicesthat the expedition needed.

In the autumn of 1803 the men of the expe-dition gathered on the east bank ofMississippi, upstream from St. Louis andestablished Camp Wood, or Camp Dubois inFrench. Over the winter the men were trainedfor their tasks. In March 1804 they attendedthe official ceremonies in St. Louis of thetransfer of Louisiana Territory from France tothe United States. In May 1804 the expedi-tion was ready to set off to the unknownwest and to chart its trails for the next gen-erations.

Joc Triglav ([email protected]) is a

contributing editor and columnist of GeoInformatics.

Part II of this article will appear in a later issue of

GeoInformatics.

The surveyor's compass, also called a circumferentor, was used not only to find north butalso to determine horizontal angles by measuring magnetic azimuths. It has also beenemployed in taking the traverse of the rivers. Invented around 1696, a surveyor's compassdiffers from a hand compass in two ways. First, it includes a sighteither two bars withnarrow slits or a tubethrough which the target is observed. A surveyor's compass ismounted on a pole or tripod to provide a steady base. Second, because the reading istaken from the back of the needle (rather than from above, as with a hand compass), thepositions of east and west are reversed. (Source: www.lewisandclarkexhibit.org)

The surveyor's chain was the usual tool of surveyors to measure land. The men stretched the chain taut between two poles or rods. The chain com-prised of 100 links, which equaled 66 feet, ie. approximately 20 m. Lewis used itoften to measure the widths of the rivers. (Source:www.lewisandclarkexhibit.org)

Such a refracting terrestrial telescope with an achromatic objective from 1800 was used by Lewis for his dailyobservations. (Source: www.lewisandclarkexhibit.org)

Prod_GEO_7_2006 27-10-2006 13:05 Pagina 17

Thierry Gregorius ([email protected])

is Programme Manager for Geomatics and

Information Management at Shells inter-

national headquarters in the Netherlands,

and was previously Global GIS Coordinator.

The views in this column are entirely personal.

When Generalists andSpecialists Collide

You probably know the story. A man was up in a hot-air balloon and shouted to a

person down below: Im lost, can you please tell me where I am? Luckily, the

person on the ground had a GPS receiver and replied: Yes, Latitude 49.8682 and

Longitude 6.1478. The balloonist scratched his head and responded: Yes but

where is that?

Sounds familiar? As information is createdand moves through an organisation, therealways comes a point where the specialistsneed to communicate their findings to thegeneralists, so a business decision can bemade. But depending on the outcome, thespecialists may wonder why the managershad not listened to them, and the managersmight feel frustrated about the informationthey were given. The truth usually lies in themiddle, of course. It is like the managershad listened in French but the specialistsspoke in Chinese.So what is the solution? Well the answer isyou, actually. No, I dont want to bore youwith how maps say more than a thousandwords. (But in fact they do. It is amazinghow much information you can squeeze intoa simple map. No spreadsheet, slide orreport can compete. We all know that.)Anyway, my point is, we as geomaticians canmake a big difference to organizational com-munications, and help bridge the gapbetween specialists and generalists. Whatmany of us do not realise is that the combi-nation of field surveyors and (geo-)informa-tion managers within a single skill pool, withmany of us having experience in both areas,is very powerful in this respect.Think about it, how many other profession-als have the privileged experience of bothfield and office exposure, encompassing theentire information trail from creation to anal-ysis to delivery? Who else gets to interfacewith the total business lifecycle?Geomaticians are some of the best-connect-ed people. Oh no, I hear you say, that isnot true. Every year I have to fight for bud-get and nobody loves me. Fine, maybe thatis the price we pay for being thinly spreadacross the big picture. If you want moredepth and stability you could consider acareer as a psychologist or hairdresser, butwe have been there before.We are not always well-connected in a VIP orhigh-profile kind of way, but that is not nec-

essary to make a difference. It is rather likebeing part of a secret intelligence network.Where I work, for example, we are often thefirst to hear of highly confidential projectsbecause the starting point is a good map. Iknow the same is true in other businesses.But as a communication tool between spe-cialists and generalists, the map is stillunderutilized. Too often still the spreadsheetengineers and PowerPoint cowboys demandall the attention of the CEO. We need tobecome more streetwise and less honest.Sorry, I mean modest. We always call a mapa map when actually it is a spatial risk dia-gram. Or a geographic opportunity rankingmatrix. Or a market scenario chart. Or aphysical asset register, maintenance sched-ule, strategic attack plan The list is end-less. As the saying goes, do we talk like theylisten? You will almost certainly have moreskill in this area than you currently imagine.When will you unlock your secret powers?

P.S. In response to my previous appeal forwhat makes geomatics such a cool disci-pline, thanks for the many replies. All threeof them. Never mind. So, thank you to Paulin India, Femi in Nigeria, and Alistair in theUK. Paul works in wind energy and sent mehis Lat/Long coordinates enabling me to seehis house on Google. Femi has just finisheda geomatics diploma and is looking to deep-en his knowledge with further studies (schol-arships, anyone?). And Alistair shared amind-boggling story about how bees, togeth-er with remote sensing technology, help withthe detection of land mines. Yes, they alsoproduce honey.

Latest News? Visit www.geoinformatics.com Oct./Nov. 2006 19

We as geomaticians can make a big difference to organizational

communications, and help bridge the gap between specialists and

generalists.

Column

Prod_GEO_7_2006 27-10-2006 13:05 Pagina 19

New Standards Enable Open S Framework for Exploiting Web-connected Sensors and Sen

Imagine a large metropolitan area in which many cities have installed different highway video monitoring systems, all connected to

the World Wide Web. Imagine a transportation manager using a map display interface to select highway segments or intersections

the manager wants to view using video. The monitors have been installed independently at different times by different vendors

using different equipment and software, but all the vendors have implemented a set of standards that enable the user's application

to discover, control and access all of the monitors in the same way, as shown in Figure 1. Many of those standards - the OGC(r)'s

Sensor Web Enablement (SWE) standards - have been approved by the OGC's membership and are beginning to be deployed in

solutions.

By Sam Bacharach

Sensor SystemsSensors are important in the geospatialworld: Measurements made from sensor sys-tems, whether from in-situ sensors (such aswater monitoring) or dynamic sensors (likesatellite imaging) make up most of thegeospatial data used in geospatial systems.In the OGC's (http://www.opengeospatial.org)SWE initiative, members of the OGC arebuilding a framework of open standards forexploiting Web-connected sensors and sensorsystems of all types: flood gauges, air pollu-tion monitors, stress gauges on bridges,mobile heart monitors, webcams, satellite-borne earth imaging devices and countlessother sensors and sensor systems. Several ofthese standards were recently formally adopt-ed by the OGC membership as OpenGIS(r)

Specifications. Others are making their waythrough the OGCs consensus process.

Sensor Web Enablement enables developersto make their Web-accessible sensors discov-erable, accessible, and controllable throughstandard protocols and application programinterfaces (APIs).

Every sensor - whether it is attached to asatellite, a tower, an automobile engine, ahuman body, a pipeline, or a buoy - has alocation, and a sensor's location is almostalways important. Sensor metadata schemasstandardized in the SWE effort provide a wayfor applications to discover the location ofsensors whose metadata is published inonline directories.

Consider the potentials of near-real time datalayers in geospatial applications. Air qualitysensors in a region can be automaticallyread at frequent intervals and those readingscan be aggregated as map layers. Floodgages and rainfall gages can provide livemap layers for flood monitoring duringstorms. Live and archived oceanographicdata from multiple agencies' buoys, ships,satellites and autonomous underwater vehi-cles can be published in online directoriesfor wide use, with applications automaticallyaggregating data from diverse sources intospatial data layers for diverse purposes.

This has significance for science, environ-mental monitoring, transportation manage-ment, public safety, border security, disastermanagement, utilities' Supervisory ControlAnd Data Acquisition (SCADA) operations,industrial controls, facilities management andmany other domains of activity. The OGC vol-untary consensus standards process coupledwith strong international industry and gov-ernment support are beginning to help thenew SWE specifications become establishedin application areas where such standardsare of use.

SWE standards enable: Web-based discovery of sensor systems

and observations, by means of catalogs inwhich sensor owners have published meta-data describing their online sensors'parameters (including location);

Retrieval of real-time or time-series observations and coverages in standardencodings;

Oct./Nov. 200620

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Figure 1: The OGC's Sensor Web Enablement (SWE) standards enable any kind of sensor system to be deployed onthe Web in a way that makes the sensors discoverable and useable through open standard interfaces. (Figure courtesy of the OGC.)

Prod_GEO_7_2006 27-10-2006 13:05 Pagina 20

Tasking of sensors to automatically acquireobservations of interest;

Subscription to and publishing of alerts tobe issued by sensors or sensor services;

Automated metadata creation: The OGCapproach to sensor and data descriptionuses XML (eXtensible Markup Language)schemas. This makes it efficient to gener-ate comprehensive standard-schema meta-data for data produced by sensors, facili-tating the discovery and interpretation of

Protocol (ASAP) specifications. Beneath the"Web public" interfaces and encodingsbased on the OGC standards, a Web servicemight communicate with its sensor systemthrough a proprietary or custom interface orthrough an interface that implements theIEEE 1451 standard.

The SWE Standards FrameworkThere are currently five proposed and adopt-ed SWE specifications: OpenGIS Observations and Measurements

(O&M) Best Practices Document[www.opengeospatial.org/standards/dp]provides a standard model for representingand exchanging observation results, allevi-ating the need for organizations to supporta wide range of sensor-specific and com-munity-specific data formats. O&M has anaccompanying OGC Best Practices Papertitled "Units of Measure Use andDefinition" (OpenGIS(r) Project DocumentOGC 02-007r4) which recommends ways tostructure values and units of measure inXML;

OpenGIS Sensor Model Language(SensorML) Implementation Specificationv0.0 (05-086r2) (http://portal.opengeospa-tial.org/files/index.php?artifact_id=12606)provides an information model and encod-ings that enable discovery and tasking ofWeb-resident sensors and exploitation ofsensor observations. SensorML provides afunctional model of the sensor systemrather than a detailed description of itshardware. Within SensorML, everythingincluding detectors, actuators, filters, andoperators is defined as a process model,which defines the inputs, outputs, parame-ters, and method for a process;

OpenGIS(r) Transducer Markup Language(TML) Implementation Specification v0.0http://portal.opengeospatial.org/files/index.php?artifact_id=14282: a method and mes-sage format for describing informationabout transducers and transducer systemsand for capturing, exchanging, and archiv-ing live, historical and future data receivedand produced by them. TML, which had itsorigins outside of OGC, provides modelsfor a transducer's latency and integrationtimes, noise figure, spatial and temporalgeometries, frequency response, steady-state response and impulse response.

live data streams. Also, simple batch pro-grams can be written to create standardmetadata for data in distributed archives.

SWE specifications are consistent with otherOGC geospatial standards as well as otherrelevant sensor and alerting standards suchas the IEEE 1451 smart transducer family ofstandards and the OASIS Common AlertingProtocol (CAP), Web Services Notification(WS-N) and Asynchronous Service Access


Art ic le

S ensor Websn sor Systems

Bijschrift: Figure 2: Solar powered wireless weatherstation. (Photo San Diego State University FieldStation Programs.)

Figure 3: A wirelessly-connected buoy provides real-time data. (Photo by Dong-kuan Liao, Virginia CoastLong-Term Ecological Research (VCR/LTER) project)

Figure 4: All necessary surveillance camera parameters, including direction of view, are accommodated in the SWEspecifications. (Photo by Luke Hennig.)

Prod_GEO_7_2006 27-10-2006 13:06 Pagina 21

Some of these are important for real-timestreaming of data. TML was introducedinto the OGC standards process in 2004and is now part of the SWE family of can-didate standards. It complements and hasbeen harmonized with SensorML andO&M;

OpenGIS(r) Sensor Observation Service(SOS) Implementation Specification v0.0(www.opengeospatial.org/standards/requests/32) defines an API for managingdeployed sensors and retrieving observa-tion data. It provides access to observa-tions from sensors and sensor systems ina standard way that is consistent for allsensor systems. The SOS is the intermedi-ary between a client and an observationrepository or a set of sensors or sensorsystems. Clients implementing SOS canalso obtain information that describes theassociated sensors and platforms. Clientstypically depend on registries that providemetadata for the different types of sensorsand the kinds of data that they are capa-ble of providing. Searches on the reg-istries might reveal, for example, all theactive air pollution sensors in London.

Sensor Planning Service (SPS)Implementation Specification v0.0;(www.opengeospatial.org/standards/requests/34) defines interfaces for a service toassist in collection feasibility plans. Itspecifies interfaces for requesting informa-tion about services for the purpose ofdetermining the feasibility of an intendedsensor planning request, for submittingsuch a request, for inquiring about thestatus of such a request, and for updatingor canceling such a request. The develop-ers and likely users of the SPS specifica-tion are enterprises that need to automatecomplex information flows in large enter-prises that depend on live and stored sen-sor and imaging data.

Areas of Sensor Web StandardsHarmonizationIEEE 1451 Transducer interfaces Developingan open standards framework for interopera-ble sensor networks requires finding a stan-dard way of connecting two basic interfacetypes - transducer interfaces and applicationinterfaces. Specifications for transducer inter-faces typically mirror hardware specifications,

while specifications for service interfaces mir-ror application requirements. Most of theOGC's specifications are service interfacespecifications (and none are transducer inter-face specifications).

Oct./Nov. 200622

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Figure 5: IEEE 1451 interfaces connect to sensor hard-ware. IEEE 1451 sensor applications connect to theWeb through SWE interfaces.

Prod_GEO_7_2006 27-10-2006 14:22 Pagina 22

IEEE 1451 Transducer interfaces(http://ieee1451.nist.gov/intro.htm) are stan-dard interfaces for smart transducers. At thetransducer interface level, a smart transduc-er includes enough descriptive informationso that control software can automaticallydetermine the transducer's operating param-eters and issue commands to read or actu-ate the transducer. The object-based scheme used in 1451.1makes sensors accessible to clients over anetwork through a Network CapableApplication Processor (NCAP), and this is thepoint where smart sensors interface to ser-vices defined in the OGC Sensor WebEnablement specifications, as shown in thefigure.

Imaging SensorsSWE's sensor model is sophisticated enoughto support encoding of all the parametersnecessary for characterizing complex imagingdevices such as those on orbiting earthimaging platforms. ISO and OGC have coop-erated to develop two ISO standards thatare relevant to the SWE effort: ISO 19130Geographic Information - Sensor and DataModel for Imagery and Gridded Data and ISO19101-2 Geographic Information - ReferenceModel - Imagery (http://www.isotc211.org/).

Two SWE Projects52 North's Sensor Web Enablement Suite52 North (www.52n.org/) is an open partner-ship organization composed of several orga-nizations founded in two cities on the 52ndparallel Muenster, Germany and Enschede,The Netherlands. The group develops opensource software, with a focus on interopera-ble web services and data encoding models

Department of Energy facility, has been work-ing with other organizations, including theOGC, to develop an open interoperabilityframework for wide-area sensor networks.SensorNet is being deployed for a variety ofpurposes, including the enhancement ofsecurity at U.S. ports and highway facilitiesand a major military installation. Systemsconforming to the SensorNet framework sub-scribe to open standard interfaces, schemasand encodings. Measurements and alertsfrom legacy and new measurement systemsare combined and integrated into informa-tion for federal, state, local and privatestakeholders across the United States.

The ORNL approach takes advantage of theconsistency built into the OGC's suite ofspecifications. The developers have embed-ded SWE encodings into application schemasthat implement the OGC's OpenGISGeography Markup Language (GML) EncodingSpecification and OpenGIS Web FeatureService (WFS) Implementation Specification.Implemented in this way, each observation isa feature.

ConclusionOGC's SWE specifications are certain to bekey parts of an integrated framework for dis-covering and interacting with Web-accessiblesensors and for assembling and utilizing sen-sor networks on the Web. OGC members willcontinue to address new areas of SensorWeb Enablement in the OGC SpecificationProgram's committees and working groupsand the OGC Interoperability Program'stestbeds and pilot projects. OGC invitesadditional participation in the consensus pro-cess and also invites technical queries relat-ed to new implementations of the emergingstandards. See web links below.

Sam Bacharach ([email protected]) is

Director Outreach and Community Adoption with the

Open Geospatial Consortium. Readers interested in

greater technical detail can download and read the

OGC SWE Architecture Discussion Paper titled The

OGC Sensor Web Enablement Architecture (OGC docu-

ment 06-021r1, www.opengeospatial.org/pt/14140).

Copyright (c) 2006, Open Geospatial Consortium, Inc.,

All Rights Reserved. OpenGIS(r) and OGC(r) are trade-

marks or registered trademarks of the Open

Geospatial Consortium, Inc. in the United States and

in other countries.

for Spatial Data Infrastructures (SDIs). Thisincludes novel web services that providefunctionality for SDI management, mobilegeocomputing, and the integration of realtime geosensor data and spatio-temporalsimulation models into SDIs.

52 North developers are currently develop-ing a multi modal client framework called'OWS Access Framework' (OXF) that simpli-fies the implementation of OGC Web Services(OWS). As part of this work, they are devel-oping Sensor Web building blocks that aregeneric open source implementations of theSWE specifications.

The Sensor Web components of OXF arebeing used in Germanys contribution to theTsunami warning system being deployed inthe Pacific and Indian oceans. They havealso been used in fire monitoring systems inSouth Africa as well as in the watershedmanagement system in The Netherlands.

Members of the OGC are currently involvedin a major testbed activity called OWS-4. Inthe OWS-4 fictional scenario, different sen-sors and other support data are required toextract reliable information to avoid a poten-tial disaster at an airport. The University ofMuenster, a member of 52 North, is partici-pating in the SWE "thread" of the testbed,refining their OXF integrated frameworkthrough feedback from multiple participantswho are building on the OXF open sourceimplementations.

SensorNetIn a project called SensorNet, the Oak RidgeNational Laboratory (ORNL), a U.S.


Art ic le

Figure 6: One ORNL application involves chemical and radiation sensors at truck weigh stations. (Photo Metler Toledo.)

Prod_GEO_7_2006 27-10-2006 13:06 Pagina 23

Fiber-Based Laser TechnologyOn the Cutting-Edge of Todays LiDAR Systems

This article takes a look at fiber-based LiDAR technology and its geospatial development

spearheaded by German-based TopoSys GmbH. Currently this is the only organization

manufacturing and utilizing fiber-based LiDAR for airborne survey and remote sensing

applications.

By Frank Arts

Broad-based Research LiDAR (Light Detection And Ranging) is oftenthought of as being a fairly recent technolo-gy. Fact is that it has been in existence foralmost four decades after laser light was firstdeveloped during the early 1960s. Sincethen the basic technology has evolved tobecome a sophisticated sensing instrumentused for an increasing and diverse numberof applications that focus on object distance,speed, rotation or chemical composition.Fiber-based lasers are currently a hot topic inthe field of on-going LiDAR research anddevelopment. There has been a growingdemand for a decrease in component size,weight and manufacturing costs. Coupledwith an increased requirement for a morerugged system with improved precision, thishas brought about a shift in the basic LiDARdesign parameters, which have stood foralmost 20 years. To address these issuesand expand markets within the medical, avi-ation safety, and airborne/spaceborne remotesensing industries, fiber technology has beenintegrated as the optical componentdesigned to increase the levels of accuracycurrently generated with the traditional mir-ror-deflection systems.

The advantages of fiber technology includerelatively low-cost manufacture using COTScomponents which produce a lightweight,compact, yet very robust laser system. Fibertechnology offers optical-alignment stabilitywhich means instrument calibration needonly be done once during the manufactureand production stage. Fiber-based lasers,with fusion spliced optical links betweencomponents are highly efficient, broadly tun-able and for a spaceflight environment inparticular, require only a low power supply.

These attributes have attracted organizationssuch as the Japan Aerospace ExplorationAgency (JAXA) and Honeywell. Both of themare carrying out detailed research into theuse of fiber-based LiDAR systems to revealareas of clear air turbulence (CAT) ahead ofapproaching commercial aircraft. The thing isthat currently there is not a system availablewhich can reliably detect this phenomenon.

NASA is also heavily involved in researchingthe operational capabilities of fiber-laser sys-tems where the size/weight ratio is an impor-tant criterion for deep-space missions. In addi-tion, ONERA, the French national researchinstitution dedicated to the study of aerospaceproblems is testing fiber-based LiDAR to modeland measure aircraft wake vortices.

Initial DevelopmentDuring the 1980s, Dornier GmbH begandevelopment of a fiber-based laser in aneffort to produce an obstacle avoidance sys-tem for military helicopters, together with anautonomous vehicle guidance sensor. Theprimary goals were precision and reliabilitywhich fiber-optic technology offered. Thisultimately led to the successful developmentof the System 1 LiDAR, which was taken overby TopoSys GmbH., a spin-off companyfounded in 1995. TopoSys used it as the basis for their subse-quent development and production of theFalcon series of Fiber-based LiDAR systems,which became operational a year later.Dornier has continued its research intoobstacle avoidance technology and now pro-duces the HELLAS system designed to warnhelicopters operating close to transmissionlines of the potential for hydro cable strikes.

Geospatial UtilizationFor the geospatial community traditionalLiDAR systems have been commercially avail-

Oct./Nov. 200624

Specia l

Fiber-based Lidar optical principle (Image credit TopoSys, Germany).

Fiber-based Lidar scan pattern (Image credit: TopoSys,Germany).

Forest canopy model (Image credit: LFG Mecklenburg-Vorpommern, Germany).

Prod_GEO_7_2006 27-10-2006 13:06 Pagina 24

able for little more than 20 years, primarilyas a range-finding technology for ground-based survey and electronic distance mea-surement (EDM) instruments. Its value as apractical airborne sensing and data gatheringtool only became apparent during the 1990swith the subsequent integration of inertialnavigation systems and GPS technology. Thisallowed precise position and orientationinformation to be applied to the point datato compensate for the aircrafts movementabout its three axes, roll, pitch and yaw. Now with the increased interest in fiber-based LiDAR and its broad applicationpotential, Alexander Wiechert, ManagingDirector, TopoSys GmbH, comments on howthe technology has developed within thegeospatial community. Todays geospatialapplications are technology-driven withimage quality and data integrity forming thebasic foundation on which many projects arebuilt. Fiber-based LiDAR systems are quicklybecoming a mainstream geo-technology byproviding application-specific precision formany assignments. It has been recognizedthat high resolution laser data can provide abasis for detailed research and analysis. Forexample, this was seen with the Tidal InletsDynamics and Environment (TIDE) project,where the interaction between landforms andecosystem structures was effectively studiedusing a new generation of data modelingtechniques. The TopoSys LiDAR provided thehigh resolution data for this project and wehave since become involved with a numberof universities and scientific institutions fromGermany, Italy, France and the UK.

The TopoSys Falcon series of LiDAR systemshave taken full advantage of the attributesassociated with fiber-optic technology togenerate high-quality elevation data. Preciselaser beam deflection, short laser pulse, fastecho detection and small viewing angledeliver an accuracy and reliability that nowposition their sensors as the benchmark

pattern. The scan lines are either uni-direc-tional or bi-directional. The individual pointsalong the scan line are produced using equalor varied angle increments at source, whichcan generate diverse and inconsistent pointspacing on the ground.

The two standard scanning techniques are:1. Oscillating Mirror2. Rotating Polygon Mirror

Oscillating mirrorUsing this technique the laser beam isdeflected by the mirror as it oscillates backand forth at varying speeds across a widerange of adjustable angles. This produces azigzag (sinusoidal) or bi-directional scan linewith non-uniform point spacing, a function ofthe cross-track and along-track spot position-ing. This random scan pattern can be partic-ularly coarse at the swath edges whereincreased along-track separation takes place.

Rotating polygon mirrorIn this configuration the laser beam isdeflected off the individual facets of thepolygon as it rotates producing a parallel oruni-directional scan line. Both mirror rotationand laser pulse rate are adjusted to corre-spond with aircraft speed and altitude pro-ducing a fairly uniform point density acrossthe entire swath.

These scanning methods are more suitableto small scale mapping projects or taskswhere the accuracy requirement is less strin-gent. Both methodologies are prone to com-ponent mechanical wear and are subject tore-calibration to ensure stated system accu-racies are maintained.

Fiber-based SystemThe fiber-based system is quite different. TheLiDAR developed by TopoSys operates withan array of 128 optical fibers in which the

technology for preci-sion DEM data collec-tion.

How AirborneLiDAR WorksAn airborne LiDARsystem generates apulsed laser lightbeam which is pro-jected onto a scan-ning mirror andreflected earthwards.Upon reaching anobject, such as abuilding, a tree or the

ground, the light pulse is reflected back tothe system. The speed of light is a knownconstant, so by using a mathematical equa-tion, the distance the pulsed light beam trav-els can be accurately calculated and effec-tively generates a Z (height) value for theobjects it encounters. The X and Y coordi-nates are determined using integrated GPSand inertial measurement unit (IMU) compo-nents which together produce precise posi-tion and orientation information for eachdata point. The result is an accurate set ofthree-dimensional coordinate data. Various other factors come into play such asslant measurements, multiple return signals,return signal intensity together with varia-tions in terrain and surface deformation how-ever, further discussion of these topics isbeyond the scope of this article.

Design DifferencesThe primary difference between the tradition-al LiDAR and the fiber-based alternative liesin the optical configuration and scanningmethodology used to deflect the laser beam.The quality of the sensor system, its opera-tional efficiency, point density and swathwidth are often established by the scanningmethod used and the resulting laser scan

Latest News? Visit www.geoinformatics.com 25

Specia l

Colour-coded lagoon near Venice (Image credit: EU-project TIDE).

Oct./Nov. 2006

3D raster city model (Image credit: Vermessungsamt Mannheim).

Prod_GEO_7_2006 27-10-2006 13:06 Pagina 25

transmitting and receiving optics are identi-cal, arranged in a linear pattern at the trans-mitter end, and a circular pattern at thereceiver end. The light from the transmitter-fibers is linked to the corresponding receiver-fibers via a very small mirror rotating at highspeed. The individual fibers are scanned insuccession and synchronized to deliver avery precise laser beam deflection with asmall viewing angle. The returning pulse isaccepted by its corresponding receiver fiberensuring absolute precision, a feature of thestable geometric orientation of the completefiber array. A single fiber is fed directly fromthe transmitter to the receiver acting as adedicated reference. Should any discrepan-cies arise in the measurement electronicsthey can be detected and immediately cor-rected to maintain data accuracy.

In general, this methodology employsextremely small moving parts, but there areno moving parts associated with the beamdeflection. Therefore, it is possible to reachscanning speeds as high as 630Hz, which isnot possible with the other two scanningmethods.

TopoSys Latest TechnologyFalcon III is the companys latest system,which generates 125,000 measurements persecond in a slight swing motion. This pro-duces a regular scan pattern with a snakingeffect which allows the point distribution toachieve optimal ground coverage. The typicalcharacteristics are a narrow viewing angle, inthis case 28 degrees, a wide beam, whichtranslates as 0.7m ground diameter from analtitude of 1000m, and high measurementoverlap. The wide beam generates multiple echoes(up to eight) from a single pulse, detectingdifferences in elevation of at least 1m. In

addition, a full wave formrecording is also available.Adjacent scan displacement is16cm with an aircraft flyingspeed of 65 m/sec. The stan-dard point density averagesbetween four and five mea-surements per 1m2 and couldbe increased to more than 25measurements per 1m2 byusing a helicopter platform forapplications such as corridormapping. Consequently, thereliance on a single measure-ment to generate an accurateresult is eliminated.

AdvantagesThe high measurement overlap

and optimal ground coverage provide a num-ber of distinct advantages. One of the most beneficial ones is the ability to detect small linear-type objects and dramatic changes inelevation, caused by planimetric featuressuch as retaining walls, ditches, ridges andembankments. The first and last echo fromall pulses which intercept these elements, are identified. This powerful edge-detection capability eliminates the require-ment to capture additional photogrammetricbreaklines in order to generate a true topo-graphic representation. Prudent data filteringwill clearly identify buildings and roof linesfor example, or drainage patterns and otherhydrographic details.This level of accuracy has enabled a diverseapplication potential, such as urban planningand the production of 3D city modelingwhere composite cadastral and engineeringdata can be integrated with rendered build-

ing structures to visualize expansion plans,redevelopment projects and infrastructurenetworks. Similarly, archeological landformsand historic sites, not readily discernible atground level, can be accurately identified,measured, analyzed and displayed veryquickly when compared to traditional data-gathering methodologies using conventionalfieldwork.

For the forest management community, fiber-based LiDAR systems enable single tree seg-mentation and crown area verification, trunkdiameter measurements and tree centercoordinates values, to be precisely deter-mined. In areas where open foliage is limit-ed, the wide beam, narrow viewing angle,and optimal ground coverage vastly increasethe probability of canopy penetration.

Multi-sensor SystemsSince 2004, the Falcon LiDAR has been inte-grated with a passive RGB/NIR line scannerto produce digital RGB and CIR true orthoimages, with the result that precision digitalelevation models and spectral image datacan be produced from a single flight.

Roman Kathofer, TopoSys representativeNorth America, explained: Both the LiDARand the line scanner operate simultaneouslyusing a single, integrated inertial/GPS systemusing independent, sensor-specific lever-armcalculations to provide position and orienta-tion information for both data sets.Generating accurate three-dimensionalgeospatial information can be a costly enter-prise so maximizing airborne mission time iscrucial. Until recently both data sets wereoften captured on separate flight missions at

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3D forest DSM, Billenhagen (Image credit: LFG Mecklenburg-Vorpommern,Germany).

3D view of point cloud for powerline corridor (Image credit: TopoSys, Germany).

Prod_GEO_7_2006 27-10-2006 13:06 Pagina 26

different altitudes, a result of the dissimilarfield-of-view and area coverage of LiDAR andlarge-format digital cameras. He continues: However, in the last fewyears a move towards integrating medium-format digital cameras with standard LiDARsystems has been very successful. The simi-larity in area coverage between both tech-nologies has improved their compatibility.This can be seen with the TopoSys Harrierseries of standard LiDARs which offer theApplanix DSS 322 digital camera systemintegrated with a Riegl laser scanner.Similarly Optech also promotes a LiDAR/digi-tal camera combination with its ALTM LiDARand Rollei camera.

True Ortho ImagesThe TopoSys LiDAR/line scanner configura-tion is also multi-sensor compatible buttakes a different approach to image genera-tion than that of a digital camera. Theimagery is generated line-by-line producing a

What the Future HoldsWiechert predicts an exciting future for fiber-based lasers: We are seeing an increase inthe demand for reliable and extremely pre-cise elevation and image data, an indicationthat the geospatial market continues todevelop in this direction. Years ago, themost common product our customers askedfor was a 2m grid size elevation model.Nowadays, it is extremely rare for someoneto ask for data with a lower resolution than1m. He continues: While the common mirror-based technology, particularly the oscillating-mirror system, seems to be at the end of itsdevelopment cycle, fiber-based technologyhas an enormous potential for further devel-opment. TopoSys has continuously focusedon precision LiDAR, both in sensor develop-ment and as a service provider. Falcon III hasbeen a major step forward. By integratingthe precision of a fiber-based laser with theproduction capacity of a mirror-based sys-tem, the geospatial community can now takeadvantage of an unmatched functionality,which is a very exciting prospect.

ReferencesKatzenbeiber, R., Schnadt, K.,Unique AirborneFiber Scanner Technique for Application-Oriented LiDAR Products (ISPRS workinggroup VIII, 2004) Wiechert, A., Precise LiDAR Data and True-Ortho Images (Map Asia, 2004)

Frank Arts ([email protected]) is a

Contributing Editor of GeoInformatics. For more

information visit www.toposys.com and

www.cluin.org/programs/21m2/openpath/lidar/.

continuous strip with a swath width 1.5times larger than the LiDAR. This increasedlateral overlap allows for minimized shadow-ing when generating mosaics from multipleflight lines.

The Falcon III multi-sensor produces what aretermed true ortho images. It applies imagerectification and georeferencing using intelli-gently-filtered LiDAR data to produce posi-tion-accurate imagery. The correct positioningof all features, such as buildings, bridges,towers and trees, is achieved by incorporat-ing the elevation data from these featurestogether with the terrain data to effectivelyeliminate object displacement. Compatibilitybetween the fiber-based LiDAR and the linescanner can be seen in its successful useparticularly for corridor surveys, where seam-less, rectified image data and a precisiondigital surface model can highlight transmis-sion line components and pipeline construc-tion details with remarkable clarity.


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Falcon system installation in a Piper Seneca II (Image credit: TopoSys, Germany).

Terrain relief image of Celtic chieftains settlement, Heuneburg (Image credit: Landesdenkmalamt Baden-Wurttemberg, Germany).

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The Geospatial Peter PrincipleWhy GIS Needs Surveyors

Many professionals rely on GIS technology to solve specific problems and answer

defined business needs. Over time, additional applications are added and connected

to the GIS that provide enhanced and new capabilities, however these new functions

may have outpaced or outgrown the system, hardware, software and data. Hardware

manufacturers and software companies keep up with these needs, but what about the

data in GIS?

By Brent Jones

Not QualifiedIn his book, The Peter Principle, LaurencePeter stated: In a hierarchy every employeetends to rise to his level of incompetence.While Peter was referring to being promoteduntil you eventually rise to a position youare not qualified to perform, the principlecan also apply to the data in a GIS. A GIS is constructed to solve a specific set ofproblems and geospatial data is developedfor the system, focused on these specificfunctions. Over time, more applications andfunctions are added to the GIS until the datais not fit for the new applications and func-tions. The specifications for the data weredeveloped for the original functions, but notall of the additional add-ons. The GIS func-tions have risen to a level where the existing

data cannot properly return the desiredresultthis is the Geospatial Peter Principle.

Investment in DataWhen new applications are added to a GIS,the data may be unfit for those applicationsfor a variety of reasons, including lack ofattributes, missing features, or inadequatespatial accuracy. The investment in data for aGIS is great and organizations generally can-not justify gathering a completely newdataset and tossing out the existing datawhen new applications are added. What isneeded is a process to incrementally improvethe quality of data in GIS, including the spa-tial accuracy of the existing data. Surveyorsare the logical contributors, but many sur-veyors have not embraced GIS technologyfor a variety of reasonssuch as the factthat existing data in GIS does not have ade-quate positional accuracy for survey func-tions, parcel record measurements are notmaintained, reliable survey data is manipu-lated and its benefits lost, and the data inthe GIS is not tied to survey control.

Parcel NetworkNew technology addresses these issues.Consider land parcels as a networka com-pilation of lines constructed from the dimen-sions from plans and deeds (record measure-ments). This parcel network looks like apiece of fabric where each of the parcel linesappears as a thread in the fabric. Next pic-ture points of this fabric pinned to theground with accurate GPS observations. Thisforms the basis of the parcel fabric. Now imagine a least squares adjustment ofthe fabric record measurements between thefixed GPS control points. The result is a sur-

vey controlled representation of the parcelrecord in a GIS. The parcel fabric technologyengages surveyors to participate in the GIScommunity and use their expertise in mea-surement to incrementally update the spatialaccuracy of data in GIS without costly whole-sale updating.

Displacement ParametersThe parcel network can be adjusted basedon field and record measurements, but otherdata in the GIS will no longer be in its rela-tive position to the parcel network. Newtechnology also exists to adjust the otherGIS data using the same displacementparameters that were derived from the leastsquares adjustment of the parcel fabricadjustment. This methodology is easily adopted by GISprofessionals for spatial data improvement ofall data in a GIS. New surveys- plans,descriptions, subdivisions, control, etc.- canbe entered into a GIS, improving existing GISdata through least squares adjustment. Whileusing this parcel fabric methodology to man-age data presents opportunities for survey-ors to participate in the GIS community, italso presents opportunities for the GIS com-munity to utilize the expertise of surveyors.

Larger DatasetsGIS technology creates efficiencies, promotesbetter decision-making, and helps us bettermanage our manmade and natural resources.This will continue and the demand for largerdatasets with more accurate data will growin turn to meet the data needs of new GISfunctions. Fortunately, systems are in placetoday to combine GIS software technologywith surveying technology and for surveyorsto participate with the GIS professional tomeet this demand and eliminate theGeospatial Peter Principle.

Brent Jones ([email protected]) is the SurveyingIndustry Manager at ESRI, and the President Elect ofthe Geospatial Information & Technology Association.

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IfSAR: an Emerging TechnologyNo Topography and Weather Constraints

In todays geo-technology arsenal, Interferometric Synthetic Aperture Radar (IfSAR) is

quickly emerging as one of the most efficient tools for generating fast, accurate, and

cost-effective digital topographic data. With its ability to penetrate clouds, rain,

vegetation and even soil, IfSAR has found a unique role by being able to successfully

map some of the more inaccessible and rugged equatorial rainforest areas around the

world.

By Frank Arts

What is IfSAR?IfSAR is an active sensor which operates inthe microwave portion of the electromagneticspectrum. Unlike LiDAR, which functions inthe visible or near-infrared part of the spec-trum, IfSAR uses microwave energy, illuminat-ing an object by reflecting off its surface togenerate elevation and feature-recognitiondata. As a remote sensing tool, IfSARbecame commercially available during themid 1990s, after several decades of techno-logical development and experimentalresearch.

The SystemA typical IfSAR system utilizes two antennas torecord elevation information at specific groundlocations in the form of x, y, and z coordi-nates. This is based on the time it takes forthe transmitted frequency to reach the targetand return to the antennas, the strength of thereturn signal, and the signal phase (the exactpoint in the signal wave oscillation when itreaches the receiver). To calculate an accurate elevation measure-ment, the system uses the phase differencebetween the signal response to the first and

second antenna. The ground coordinate valuesare determined using an integrated inertialmeasurement unit (IMU)/GPS system, a prima-ry component in IfSAR technology.

Radar FrequenciesUsing wavelengths of between 1cm and100cm, two radar frequencies are used, X-bandand P-band, each of which reacts differentlywith the surfaces they contact. For forest map-ping, the higher frequency X-band will interactwith smaller features, such as leaves and smallbranches, producing a first return backscatterthat will enable accurate tree canopy eleva-tions to be computed as a digital surfacemodel (DSM). Depending on the polarizationmode chosen, vegetation type and physicalstructure can also be determined. In contrast, the lower frequency P-band willpass through the dense vegetation and reflectoff the ground surface, tree trunks, largerbranches and under-canopy foliage, deliveringa diverse set of data. A bald earth elevationcan be determined as a digital terrain model(DTM) as well as forest biomass information,and to a certain degree soil substructure.Resolution is governed by the pulse durationand the length of the antenna aperture, theshorter the pulse, the higher the cross-trackresolution. The longer the antenna aperture,the higher the resolution will be in the direc-tion of flight.

Operational ConsiderationsAn aircraft-mounted IfSAR system is config-ured to produce a side-looking swath thatwill generate wide-area coverage. The imageangle is typically between 30 and 60degrees, which means areas in the shadow ofhigh relief terrain cannot always be targetedunless additional flight lines are carried outto capture these areas. Because of the side-looking perspective the image is more fea-ture-accentuated than a vertical aerial photo-graph, visually enhancing the perception ofelevation. Depending on the particular sys-tem, pixel resolution is generally between1.25m and 3.0m and average tile size is10km x 10km. The technologys penetration capability(cloud, rain, haze, smoke, light snow) isremarkable, eliminating the most commontime-delay problems associated with airborneoperations, inclement weather and clouds

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The island of Sulawesi, located in the middle of the Indonesian archipelago, credits its unusual geographic shapeto the collision of three large land blocks converging some 15 million years ago. The landscape is dominated byvolcanic mountains and lowland plains, which is evident in this 3D perspective image showcasing Intermap's digi-tal surface model. Image credit: Intermap Technologies Corp.

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over the target area. In addition, missionshave the option of being flown at night whenturbulence is much less of a problem.Depending on the project accuracy require-ments and the inaccessibility of the terrain,ground control is not always necessary. Thedirect georeferencing capability of the inte-grated inertial/GPS system will control thedata. However, the use of strategically locat-ed radar reflectors and GPS base stations canimprove results.

Geospatial ProductsThere are a number of geospatial productsderived from IfSAR data, the most commonone being DTM, DSM and orthorectified radarimage (ORI). As the term suggests an ORI isa grayscale radar image which has had thegeometric distortion removed using the eleva-tion data to perform the rectification. In addi-tion there are options to produce valueadded products such as contours,Topographic Line Maps (TLM), shaded reliefimages, slope and aspect computations andthematic maps. In many tropical rainforestareas, where very little accurate mappinginformation has been available, these productoptions are proving invaluable.

poor weather conditions, dense forest coverand rugged terrain.

EarthDataUS-based Earthdata has been using itsGeoSAR system since 2002. It is mountedonboard a Gulfstream II jet aircraft, and is theonly system capable of generating single-pass,interferometric, simultaneous X and P-bandradar data for each flight line it maps. TheGeoSAR system comprises two units, onepositioned on either side of the aircraft plus acentral-mounted terrain-profiling LiDAR whichprovides high accuracy terrain data to aug-ment ground control. Operating at altitudes ofbetween 11km and 12km, and at a speed of400 knots, GeoSAR can capture 288 km2 ofdata per minute.

The dual-sided configuration allows for redun-dant coverage, ensuring every point on theground is targeted twice from the left andtwice from the right, using four X-band andfour P-band antennas to deliver overlappingswaths on opposite sides of the aircraft. Thisarrangement generates eight separate mea-surements for every map pixel which enablesfull-image mosaic-generation, with the elimina-tion of shadowed areas and obscured featurelayover. For location-specific applications, thesystem can also be flown in a circular patternto produce high resolution (50cm) radarimagery from a 360 degree aspect.

Working with the National Geospatial-Intelligence Agency (NGA), EarthData begancapturing IfSAR data as part of the GLAD-Pprogram (GeoSAR Latin America DemonstrationProject) in 2003. The program generated193,000 km2 of data, much of it in previouslyun-mapped and remote regions of Colombiawhere the rugged terrain is often under thickjungle canopy and c

geoinformatics 2006 vol07

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