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LiDAR Tools, Applications and

Experiences


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Overview

October 2006 GRF LiDAR Data Collect

Data Issues .

LiDAR tools, products and application areas Recent GRF LiDAR Projects

Lessons Learned


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LiDAR Defined

LiDAR is a an acronym for Light Detection And Ranging thatrelies on measuring the distance from an aircraft to the Earths

surface by precisely timing the round-trip travel time of a briefpulse of laser light

The travel-time is measured from the time the laser pulse is

fired to the time laser light is reflected back from the surface.

The reflected laser light is received and converted to distancefrom the plane to the surface based on the speed of light.


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LiDAR Data Collection

Laser Pulse Returns


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2006 AGRGLiDAR Data Collect


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3-Stage LiDAR Data Collection and

Management Process

1. Identification of Study Area2. Supply study area background files

3. Flight Planning

4. GPS Base Station Operation (Ground Crew)5. Hardware Install (Flight Crew)

6. In-Flight Data Collection

7. Raw data processing

8. Point Classification and Export

9. Creation of DEMs and other products

Pre-Flight

Post-Flight

Collection Day


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Identification of Study Area


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Supply of Background Files

Provided the following;

Georeferenced NTS Topo Map Image

Rivers, Roads etc. as shapefile vectors Survey Monuments text file


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Selected Best Available Base Station Monument


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Flight PlanningOptechs ALTM Nav Software is Used to Plan Flights


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Hardware Install


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2005 AGRG Summer LiDAR Workshop


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?


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GPS-Base Station Set-up96G7002 CRK 120 48 56 38.4634 57 56 59.0467 100 Y A R 2003 68.554 100 1 P 1 CGVD28 1999 1 1 012A13

98F001 98F001 100 48 56 38 57 56 59 S S 64.970 100 1 P 1 CGVD28 1999 1 1 012A13

98F002 98F002 100 48 56 38 57 56 59 S S 66.563 100 1 P 1 CGVD28 1999 1 1 012A1396F003 96F003 100 48 56 38 57 56 59 S S 67.709 100 1 P 1 CGVD28 1999 1 1 012A13


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Raw Data Processing

Data Sources

Aircraft Global Positioning System (A-GPS)

Base Station GPS Inertial Measurement Unit (IMU)

Inertial Navigation System (INS)

LiDAR Returns


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Applanix PosPac Software

Raw Data Processing(ALTM Workflow)

SBET File

A-GPS Base Station GPS IMU INS+ + +

Raw Flight Data is processed in PosPac to create an SBET File.

PosPac is used primarily for 3d sensor location.


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Raw Data Processing

Optech REALM Software

LiDAR Return

Data

LAS Binary File

SBET File

+

SBET file and LiDAR return data is processed to create a LAS Binary File


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Point Classification and ExportLAS files are processed in TerraScan to classify points as vegetation, ground, non-

ground etc.

LAS Binary File

VegetationGround Non-Ground

TerraScan (Microstation)


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LAS Files

LAS (LASer) contains LiDAR point datarecords which combine GPS,IMU and

laser pulse returns to produce X,Y and Z

point data.(others too like intensity)

ASPRS Open Data specification/standard

and format

Specification now at version 1.4, 2.0 is in

the works


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Item Fmt 0 Fmt 1 Fmt 2 Fmt 3 Fmt 4 Fmt 5 Fmt 6 Fmt 7 Fmt 8 Fmt 9 Fmt 10

X X X X X X X X X X X X

YX X X X X X X X X X X

ZX X X X X X X X X X X

IntensityX X X X X X X X X X X

Return NumberX X X X X X X X X X X

Number of Returns (given pulse)X X X X X X X X X X X

Scan Direction FlagX X X X X X X X X X X

Edge of Flight LineX X X X X X X X X X X

ClassificationX X X X X X X X X X X

Scan Angle RankX X X X X X X X X X X

User DataX X X X X X X X X X X

Point Source IDX X X X X X X X X X X

GPS Time X X X X X X X X X

Red X X X X X X

Green X X X X X X

BlueX X X X X X

Wave Packet Descriptor Index X X X X

Byte offset to waveform data X X X X

Waveform packet size in bytes X X X X

Return Point Waveform Location X X X X

X(t) X X X X

Y(t) X X X X

Z(t) X X X X

NIR X


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TerraScan Classification Options


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Point Cross-Section


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Point Classification and Export

Classified LAS points are exported as ascii xyz files

VegetationGround Non-Ground

Ground.xyz Non-Ground.xyz Vegetation.xyz

TerraScan


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RESULTS


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OCTOBER 2006 LiDAR


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Lots of Points..

343,083,691 Total Points!

More than 25GB of Data!


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Tiles make data Manageable

523 tiles in all


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Delivered Data Formats

14 industry standard LAS binary all hits files.

523 ASCII space delimited x,y,z,i files for

Ground Only Returns

523 ASCII space delimited x,y,z,i files for All

Hits


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Derivative Product Development

ReformattedASCII

Raster

ASC Raster

GDB

Raster

MosaicsSurfer

Grids

Shapefiles

DEMS

DSMSlope

Grids

Vegetation

Grids

Aspect

Grids

Hillshade

Grids


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342475

Ground Points

Points


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DEM from Ground Points


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Hillshade


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Slope


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Aspect


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Surfer Tile294 Ground ONLY


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Surfer Tile294 Ground ONLY


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Selected LiDAR Software TerraScan (Part of TerraSolid)

Surfer

QT Modeler

LP360

LiDAR Analyst

LASTools

Voxler

Pointools

ArcMAP/ArcToolbox


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Terrasolid(Terrascan)

S f


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Surfer


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QT Modeler/Reader(Applied Imagery)


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LP360 in ArcMAP


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LP360 in ArcMAP

LiDAR Analyst (Overwatch)


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LiDAR Analyst (Overwatch)

l ( i b )


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LasTools(Martin Isenburg)

* txt2las.exe converts LIDAR data from ASCII text to binary LAS format

* las2txt.exe turns LAS into human-readable and easy-to-parse ASCII text

* lasinfo.exe prints out a quick overview of the contents of a LAS file

* las2shp.exe turns binary LAS into ESRI's Shapefile format

* shp2las.exe turns an ESRI's Shapefile into binary LAS

* lasmerge.exe can merge several LAS files into one * las2las.exe extracts only last returns, clips, subsamples, etc ...

* lasthin.exe implements a simple point thinning algorithm

* las2tin.exe triangulates the points of a LAS file into a TIN

* las2dem.exe rasterizes them into a DEM

* las2iso.exe extracts, optionally simplified, elevation contours

* lasview.exe visualizes the contents of a LAS file.

* lasclip.exe clipping LiDAR points

* ArcGIS for Desktop toolbox.

Voxler (Golden Software)


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Voxler (Golden Software)


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ESRI Las Dataset


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ESRI Tools

Point File Informationfile name, point count, z-minimum, z-maximum,

and point spacing

LAS to multipoint

LAS Point Statistics as Raster

pulse count, return count, intensity range others

LAS Dataset to Raster Entire Section dedicated to LAS in help

including Canopy Height workflow


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2006 Data Issues

and

Processing Screw-ups !


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City and Marble Holes


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Low Point Density

0.63 points/Square m

Up to 15 points m2possible


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March 2009 before all issues were fixed.


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Applications

(For good LiDAR!)


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What is it used for ?

Lidar data can be used to accurately measure the topography

of the ground, even where overlying vegetation is quite dense.

The data can also be used to determine the height and density

of the overlying vegetation, and to characterize the location,

shape, and height of buildings and other structures.


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Selected Products, Uses and Applications

High Accuracy DEM (Derived Products Slope, Aspect etc..)

3D fly through simulations

Landscape visualizations

Tourism and Municipal applications Accurate contours for a variety of mapping applications

Geophysical applications and visualizations

Flood Hazard Mapping, Coastal zone mapping and assessment

Delineate vegetation height and type


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Classified LiDAR(Leading Edge Geomatics)

RGB Cl ifi d LiDAR (L di Ed G ti )


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RGB Classified LiDAR (Leading Edge Geomatics )


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Recent GRF LiDAR Projects

LiDAR /Ortho Data Collection for 10 sites in

Western Newfoundland collected in July 2010

Avalanche Research with MUN SWG Campus

Geohazard Monitoring in conjunction with CCRS

New flight planned for this Summer 2013

A l h H d M


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Avalanche Hazard Maps


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Avalanche Services/Web Apps


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Google/JavaScript App


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Daniels Harbour:


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The houses are constructed on a marine

terrace with a surface elevation of about 24

m above present sea level. The NorthernPeninsula Highway is located about 20-70

m inland of the cliff edge, between which

14 buildings were located.October 20, 2006

April 15, 2007

Newfoundland, Canada

50 0 50There is no an existing high resolution DEM. Therefore, 3-pass

Daniels Harbour InSAR Displacement Map:


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RADARSAT-2 Ultra Fine

Master: 20090610

Slave: 20090914

Descending Orbit

Perpendicular Baseline: 67 m

Deformations are only shown where the scene coherence exceeds 0.5

RADARSAT-2 - 3x3 multi look intensity image

-50 0 50

Vertical displacement [mm]

April 2007

differential interferometric processing applied to monitor the

temporal evolution of landslide.


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F A (D i l h )


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Focus Area (Daniels hr.)


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T i


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Terrain

1 R


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1m Raster

Hill h d


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Hillshade

Sl


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Slope

A t


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Aspect


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L L d


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Lessons Learned

Discuss data sharing policies and distributionbetween partners, vendors and external

stakeholders

Dont be locked into a single GIS platform usethe best tool for the job(Some SW slow.)

Leave the raw LiDAR processing to the

vendors focus on GIS ready deliverables Use a reputable experienced vendor (Highly

recommend Leading Edge Geomatics.

Lidar Project Partnerships


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Lidar Project Partnerships
http://www.intrd.gov.nl.ca/intrd/

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