n29 - geodetic and photogrammetric

7/30/2019 n29 - Geodetic and Photogrammetric

1/10

cuadernosde arquitecturamesoamerlcana nmero 29 marzo 1995

SE\tINARlO 1>l::AltQl ITE(Tt ItA PR"]IISP,"IC.ACf::\ITROo.: 1.." ' ...STlG,\CIO....:s 1:.""'1 ARQl-mXJUtA.yUItBA....s\to.-ACl:LTAD DEARQI rTECJltll\


2/10

cuadernosde arquitecturamesoamericanaCENTRO DE INVESTIGACIONES ENARQUITEcruRA y URBANISMOSEMINARIO DE ARQUITEcruRAPREHISPNICAFundador:Paul Gendrop tEditor:Juan Antonio SillerConsejo Editorial:JessAguirre CrdenasGeorge F. AndrewsRicardo ArancnJuan Benito ArtigasAlfredo Barrera RubioJohanna BrodaMnica Cejudo ColleraXavier Corts RochaBeatriz de la FuenteHorst Hartung tHasso HohmannMiguel Len PortillaJaime Litvak KingH. Stanley LatenAlejandroMangino TazzerLinda ManzanillaKarl Herbert MayerAugusto MolinaVctor RiveraRicardo de RobinaErnesto Velasco LenRedaccin y Diseo Grfico:Ma. Cristina AntnezM.Juan Antonio SillerRevisin Final:Ma. Cristina AntnezM.Traduccines:Natalie Bouchery Ma. Cristina Antnez M.Armado-edicin en tipografa electrnica:A. M. Ediciones Electrnicas. Cuernavaca,Morelos. Tel (73)19-03-73 (Fax)Impresin:Grficas Artsticas, S. A. de e. V. Impresores.Prolongacin Sanctorum 6, Lamas de Sotelo,53390, Naucalpan de Jurez, Estado deMxico.Telfono: (5)3-95-37-11Distribucin:En las libreras de la Distribuidora de Librosde la UNAM (Centro Comercial - e.U.) yCentro Cultural Universitario - Ce. U.)TiriVe: 1000 ejemplaresNota:Los artculos deber n ser r edac tados enespaol y acompaados de un breve resumenen ingls o bien en ingls con resumen enespaol. Sern dir igidos al Seminario deArquitectura Prehispnica, Facultad deArquitectura, UNAM, San Angel, DelegacinAlvaro Obregn, 01000, Mxico, D. F.El consejo editorial, con arbitraje internacional, se reserva el derecho de seleccin. Autorizada la reproduccin parcial de artculos acondicin de que se cite la fuente.

nmero 29 marzo 1995ARQUITECTURA MAYA 8

ndiceEDITORIAL 1English 2

F r a n ~ a i s 2PLAN DE INTERVENCIN DEL TEMPLO 1DE TIKAL,EL PETN, GUATEMALAOscar Quintana .................... .................... ..................... ................... ..................... ......... 3LOS TRES CENTROS MAYORES A LO LARGO DELRO CHAMELECN EN LA REGIN DE LA ENTRADA, HONDURASKazuo Aoyama ............................... .................................... ................................. .......... 15GEODETIC AND PHOTOGRAMMETRIC SURVEY OFMONUMENTS AND SITESRobert Kostka y Hasso Hohmann 21CONSIDERACIONES SOBRE LA TCNICA CONSTRUCTIVA DE LA ARQUITECTURA PUUCHans Prem 29FICHA TCNICA DE REGISTROARQUITECTNICO:PROYECTO ARQUEOLGICOXKIPCHHans Prem ....................................................................................................... 39LAS PLAZAS DE HORMIGUERO: TRANSFORMACIONES URBANAS EN UN SITIO MAYADE LA REGINROBECArturo Pascual Soto 45UN EJEMPLO DE LA EVOLUCINDE LA ARQUITEC-TURA PUUC, EL GRUPO AH-CANUL DE OXKINTOKAlfonso Muoz Cosme y M. Cristina Vidal Lorenzo 53ALGUNAS CONSIDERACIONES SOBRE LATORRE DEPALENQUE, CHIAPASMiriam Judith Gallegos Gmora ................................................................ 59ATLAS ARQUEOLGICO DE YUCATN: INFERENCIASSOBRE LA UBICACINDE LOS ASENTAMIENTOS PRE-HISPNICOSEduardo B. Kurjack, Norberto Gonzlez y Silvia Garza 71THE PALACEATSANTA ROSAXTAMPAKGeorge Andrews ............................................................................................................ 79

Prximos Nmeros PINTURA MURAL 1 ARQUITEcruRA DEL ALTIPLANO 3 JORNADAS DE ARQUITEcruRA PREHISPNICA EN MESOAMRICA VIHOMENAJE A GEORGE ANDREWS JORNADAS DE ARQUITEcruRA PREHISPNICA EN MESOAMRICA VIIHOMENAJE A STANLEY LOTEN TEORA E HISTORIA DEL URBANISMO EN MXICO - POCA PREHISPNICA 3 DOCUMENTOS DEL PATRIMONIO CULTURAL2 NDICE DE LOS CUADERNOS DE ARQUITECTURA PREHISPNICA 1 DOCUMENTACIN DE ARQUITECTURA 1 GEORGE ANDREWSEl Consejo Nacional de Ciencia y Tecnologa (CONACYT) ha includo estos Cuadernos deArqui tectura Mesoamericana en el NDICE DE REVISTAS CIENTFICAS MEXICANAS DEEXCELENCIA. Mxico, D. F., abril 15 de 1994.


3/10

GEODETIC AND PHOTOGRAMMETRIC SURVEY OF MONUMENTS ANDSITES

Robert Kostka and Hasso Hohmann *

To analyze architectonical vestiges and the architecture of ancient cultures, adetailed documentation is themost importantand basic action. To reconstruct nLnsand to analyze its orientation, not only of isolated monuments and to make com-parative studies. The authors propose that the geodesic and photogrammetricmethods could be ve!)' efficientfor the field work in the evaluation of the elementsandmoreover if they are supported with the registration ofdata in drawings.

Vieta. (Fig. 1).- StructureIV at Becan, Campeche: perspective -viewfrom the southwest;at the northern side of Structure IV thcre arefour stories.

* Investigador/Doctor, Miembro del ConsejoEditorial de Cuadernos de Arquitectura Me-soamericana.

1.) For the analysis of the architecture or architectural remains ofancient cultures, it is very important to use detailed documentation. This is true for single monuments as well as for comparative studies, the reconstructionof ruins or the examination of e.g. orientation.Uthe architectureis very complex, not rectangular,the ground plan very differentiated, large-scale, on different leveIs etc., it is very difficult to produce an architectural documentation by applying common methods like hand-recording. Then,geodetic and photogrammetricmethods may be more efficientfor fic1dwork and evaluation ifthey are cleverly supported byhand-recordings.2.) Structure IV at Becan, a ClassicMaya bui lding in Campeche,Mexico, may serve as an exampIe. It should demonstrate thepossibilities and limitations fousing geodetic-photogrammetric surveyingmethods in combination with other recording methods. Structure IV at Becan is asingle architectural object,which can hardlybe recorded byhand-recording only (fig. 1).What makes recording difficultare, for example, a very complexand irregular non rectangularground-plan, different levclswithin one story, four differentstories - the third one with hardlyanyvisible connection to the outside, surface not to be definedgeometrically - due to the destruction caused by nature such

as erosion and vegetation. Sorneparts of the architecture are fragile and cannot be entered. Mostrooms cannot be seen frorn theground-Ievel, as they are hiddenby outer walls. These parts ofthearchitecture, however, also haveto be recorded.

3.) It is necessary to know severalpoints of the object in positionand c1evation if an exact geodetic survey of a building-cornplcxlike structure IV at Becan is toby car ried out. For detailedmeasurements, these points canbe used as fixed-points. Variousgeodetic methods can be usedfor recording these points like,for example, measuring anglesnot space-ang1es but horizontaland vertical angles - or measuring horizontal and/or obliquedis tances. Inst ruments like atheodolite, distancer or a cornbination of both must be available.The measurements may be carried out by polar survey (fig. 2)or by intersection from a pair ofpoints (fig. 3). U the object islarge, more structured and cornplex, so that not aH interestingpoints of the object can be seenfrom one point or from one pairof points, measurements are tobe taken from several points (fig.4). The position of these pointscan be recorded bymcasuring atraverse and by detcrmining theangles and distances betweenthese points. I f there is an already existing triangulation net,the computations need not bebased on a local position and

21


4/10

Arriba. (Fig. 1).- Plan of the Struc tu re IV at Becan, Campeche. Abajo. (Fi

g.l). A section oC S truc tu re IV at Becan, Campeche.

22

----1-==;----I 1 oe "


5/10

height system. Then the measurements can be integrated intothe more comprehensive systemof the triangulation net.Using a more comprehensivetriangulation net has the advantage of representing the resuItsof geodetic surveys carried outat different sites within onesystem, which aI10ws the varioussites to be compared in heightand position. The orientation ofsuch a site-map may not only bebased on the northern directiondefined by the grid (of coordinates) but also on the True Northor Astronomical North definedby surveying stars or the sun forthe azimuth determination andon the Magnetic North determined by using a compass. It is important to realize, however, thatthe directions based on the various determinations of theNorth mentioned aboye are notto be interchanged and especiaI1y that the Magnetic North isnot constant, but changes its declination with time (fig. 5).It is not possible to carry out ageodetic survey with absoluteaccuracy. The letIter depends onthe instruments applied, on themethod and disposition (and ofcourse on the way the measuredpoint can be defined). An adjustment is possible if t he re arepoints which have been determined more than necessary for defining their positions. Such anadjustment makes the results ofthe measurements and caIculations accurate and the degree oftheir accuracy more reliable.

4.) Photogrammetric surveys for record ing architec ture have theadvantage that the surveyerneed not touch the object whichhas to be recorded, as the measurement process (photogrammetric survey) is carried out bytaking metric photographs. Theprocess of the measurement itseU, therefore, is very short ; itonly takes the moment of exposure.The evaluation can be doneat any other place later on.GeneralIy, photogrammet ricsurvey may be descr ibed as the

Up. (Fig. 2).Polar-suIVey with a distancer. Down.- (Fig. 3). Measurements through intersectionforma a pair of points with a theodolite.

23


6/10

Up.- (Fig. 4).- Measurements from several points. Down. (Fig. 5).-True North andMagneticNorththe declination of Magnetic North changcs with time.

proeess of produeing a metriepieture of the objeet to be reeorded (fig. 6) and of obtaining information on the object recorded by measuring the imagecoordinates. The measurementswithin the photograph must becarried out with great accuracyas the picture is usually verysmall in re lation to the object.Moreover, it is necessaryto haveinformation about the inner andouter orientation. Jnner orientation means information aboutthe photogrammetric camera(focallength, image coordinatessystem, distortion, outer orientation is defined by informationabout the coordinates andheight of the camera station andthe orientation of the cameraaxIS.Non-metric cameras canbe usedonly with considerable improvisation for photogrammetric surveys. The instrument (photogrammetric camera, phototheodolite) should be adapted to thispurpose. These cameras are quite expensive as they must be extremely accurate. Apart fromthis, sorne equipment is requiredfor the evaluation of this photographic material.Photogrammetric surveys canbeearried out by using single pictures. A clear result can be obtained only ifthe reeorded object isplane or iffurther information isavailable. The evaluation is possible, for example, by rectifyingthe photograph, which is easiestif the object plane is paral lel tothe image planeoThen the objectand the image can be related toone another as far as propor-tions are concerned. Only thescale of the image has to bechanged. For recording threedimensional objects, a commonmethod is the so-called "stereophotogrammetry".The surveyer needs specialequipment for producing a stereoscopic pair of images. Withthis method, the position of thecamera is very important (fig. 7),which means tha t the surveyermust pay at tention to the base-

:0 __/ \ "~J _______

24


7/10

Up. (Fig. 6).- Metriccamera on top of an adapted theodolite for a metric picture. Down.- (Fig. 7).The same combination for a pair of metric pictures - a photogram.

depthratio, the relationbetweenthe distance of the two camerastations to the camera-to-objectdistance and the orientation ofthe single pictures. Photographswith camera axes at right anglesto the base line, as well as parallel and perpendicular photographs to the right and left withhorizontal and inc1ined cameradirections are often used for recording three-dimensional objects (fig. 8). The choice of thebase-line depends on the localcircumstances. It should minimize the number of non-visibleareas. Vertical or oblique photographs taken, for example, froma heIicopter, maybe useful additions to such stereopairs.For the right choice of scale andheight connections, the geodeticmeasurements are necessary.Position and elevation of the camera station and of sorne striking points of the specific objectas weIl are necessary to guarantee good evaluation to scale.Even objectts with shapes whichare not or difficult to define geometrically can be recorded bystereo-photogrammetry. I f theposition and eIevation of certainpoins have to be recorded asexactly as possible; it is helpful totake sorne overlapping picturesof the object (fig. 9). From thesepictures, information about directions (from the camera station to the point of object) necessary for the determination ofpoints. Work with modern facilities like computers no longer require a strict orientat ion to theimage. Computing makes it possible to obtain the most reliablemeasurements and their uncertainty by running and adjustment routine.Photogrammetric recording offers various advantages: * thegeodetic work at hte object itselfonly takes a very short time, andthe detai led work can be donelater on, even at a time when theobject does not exist any more. You need not to touch orwalkon the object. One mainbenefit is the possibility of

25


8/10

Up. (Fig. 8).- Different ways to take stereo-pictures. a) perpendicular photographs taken at rightangles to base line; b) perpendicular photographs taken with camera in horizontal parallel direclions, pointing to the left; c) photographs with obligue camera axes - at right angle to base line.Down. (Fig. 9).- Points represented in several overlapping pictures.

26

recording shapes which arealmost to define in geometric terms by means of stereo-photogrammetry. Theseshapes may then be represented in the form of equidistants, vertical or horizontal sections.These have only been sorne exampIes in favour of this geodetic method. Of course, there are also sornedisadvantages which have to be mentioned:. the high cost of the equipment for fieldwork and evaluation;

.areas of objects maybe nonvisible due to the position ofthe camera stations. Therefore, important details maybe missing.In such cases, it is necessary tocarry out hand-recordings based ongeodetic photogrammetric survey.

Both surveying methods have tocomplement one another.5.) For the hand-recording method,only very simple and inexpensiveinstruments have to be availablelike a tape, a water-Ievel and aperpendicular. The method ofhand-recordingshould alwaysbe

applied when the expenditurewould be higher with other methods. Simple architectural structures, for examp1e, with geometrically definab1e forms, especially the usually non-visible inside areas, should be recordedby hand. In manycases, a combination of both, the photogrammetric survey and hand-recording is best.The first and most importantstep ofhand-recording is the decision ofthe best way of objectrepresentation: where to situatethe virtual horizontal and vertical sections through the object;where, how and in which direction to draw the front-views.Thesetions and views have to be chosen in such a way that the representations allow a clear description of the object. No detailshould be missing, because atthe end it should be possible toreconstruct the object from thegraphic representations.


9/10

Up.- Structure IV of Becan. Down.- Map of the Maya area showing the site of Becan. Both weredrawn by George F. Andrews.

Literature

0Z 5 5 0 7S 1OD IC I l, I , , I

POTTER, David F.1977 Maya Architecture ofthe Central Yucatan Peninsula. Mexico. Publication 44, Middle A-merican Research Insti tute,Tulane University, New Orleans.

IIOIIMANN,lIasso1989 "Structure IV at Becan, Documentation and Analysis onForm and Construction of itsArchitecture". Mercedes de laGarza, el al. Hrsg., Memoriasdel Segundo Coloquio Interna-cionalde Mayistas, Vol. 1: 127138, UNAM. Mxico, D. F.

CUlr or , . [ J l eo

nument, which cannotbe rcorded satisfactorily with other geodetic methods.Our geodetic survey of StructureIF at Becan may serve as an examplefor the efficiency of the combination

of both methods. It took only threepeople two days to do the fieldworkat Structurc IV at Becan.The evaluation, however, took several monthsand resulted in more than 120 drawings to scale. Besides, the combination of stereo-photogrammetry andhand-recording enabled a bcttcrgraphic rcpresentation of the structure as can be demonstrated bycomparing it with earlier drawings byDavid F. Potter (Potter, 1977: fig. 6, 8, 9.(fig. 11).

The second step is to produce architectural sketches and to definewhere the measurements have to bemade.The third step is to per fomr themeasurements with the aboye mentioned instruments. The measurements consist mainly of horizontal

and vertical distances. Irregular angles can be measured by taking thediagonales. For control purposes acomplete system of triangles shouldbe established.

The last step is to draw the wholematerial to scale.Very often, ancient monuments orarchaeological sites are in a verypoorstate. I f themissing parts of the architecture should be rcprcsented in reconstrucion drawings different ways

of representation must be used forexisting, inductively added andhypothetically completed parts bymeans of a solid line, a broken or adotted line (fig. 10).

In addition, photographs takcn ofthe recorded architecture may be ofgreat value. Frontal pictures of everysinglewall are most useful; such photographs canbe enlarged or reduccdto certin scales. Should any measurement be missing, it can be obtainedfrom these pictures. Especially f a ~ a -des showing flat dctails can be recorded and representedquite easilywiththis method. Therefore, the survcyershould be generous in using photomaterial for such frontal pictures. I fpossible, a photograph should be taken of very single detail of the wall.6.) Air pol1ution, rain, vegetat ion

and especiallymen keep on destroying monuments and sites allover the world. We cannot saveall the innumerable monumentsbecause of financial contraints.Thus, we havc to find methodswhich allow us to record aH existing fragments of various cultures as quickly as possible. At themoment, it is not necessary toevaluate all the recordcd material, but it is our tak to file it forfuture generations.From this point of view, the photogrammetric method turns out to beveryefficient. However, it should notreplace hand-recording but shouldbe used additionally to produce thebest results. The photogrammetricmethods should help to record mo-

27


10/10

BECAN, STR.IV.

Vp.- Existing architecture inductivly added parts hypothetically completed parts. Down.- Map oC H. Hohmann and R. Kostka oC Structure IV at Becanwith contourlines.

I - - - + - - - - - - " ' . ~....., . ~ ~ ~ : : : ' : . W : : : : ~ ~ ; : : .,.; : : ; 1 ~ b : ; ) : ; b : ' ; b ; : : -

4/)rntOf'cd 1----- ._-._.. _ .

28

n29 - geodetic and photogrammetric

Documents