Data format: Raster Dataset
File or table name: Ralls Island, The Pas LiDAR DEM
Coordinate system: Universal Transverse Mercator
Theme keywords: elevation, environment, geoscientific information
| Ralls Island, The Pas LiDAR Bare Earth | |
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Data format: Raster Dataset File or table name: Ralls Island, The Pas LiDAR DEM Coordinate system: Universal Transverse Mercator Theme keywords: elevation, environment, geoscientific information |
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Abstract:
Description of data and location to be completed by client. LiDAR data was collected using LSI's proprietary Helix LiDAR system - Novatel GPS and IMAR inertial unit, coupled to a Riegl Q560 digital waveform ranging laser and mounted in a Bell 206 helicopter. LiDAR was collected at 600m AGL, and a ground speed of 120km/h. Data is in an ASCII XYZ coordinate format. |
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Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
Description of data and location to be completed by client. LiDAR data was collected using LSI's proprietary Helix LiDAR system - Novatel GPS and IMAR inertial unit, coupled to a Riegl Q560 digital waveform ranging laser and mounted in a Bell 206 helicopter. LiDAR was collected at 600m AGL, and a ground speed of 120km/h. Data is in an ASCII XYZ coordinate format.
The Province of Manitoba is committed to the continuous improvement of the Province's flood protection infrastructure capabilities. Appropriate and judicious investments in flood protection infrastructure have proved effective in protecting communities from the devastating impacts of severe flooding. The Province of Manitoba and The Rural Municipality of Kelsey recognize the need for permanent flood protection infrastructure for the Saskatchewan River, Ralls Island area. The purpose of LiDAR topographic surveys is to implement a program to construct new flood protection infrastructure and increase the capacity of existing flood protection infrastructure to stabilize the economy and protect the people and property of the Ralls Island area. Obtaining detailed topographic information of the Ralls Island area is required for the accurate preparation of flood protection dikes. Therefore, LiDAR topographic surveys are to be obtained for The Ralls Island area.
ground condition
none
250, 3115 12th Street NE
This data set was developed for Province of Manitoba by LiDAR Services International Inc.
Ground points were initially classified using an automatic classification routine. The ground surface model was edited and verified by creating a shaded relief model and identifying erroneous points and voids in the ground surface.
Data was verified by viewing shaded relief models. Points were checked against those from adjacent flightlines to ensure positional accuracy. The intensity of the LiDAR returns was viewed and compared against adjacent data to verify horizontal positional accuracy.
Horizontal accuracy is verified by comparison of horizontally identifiable features in the LiDAR data against similar features in another flightline of LiDAR data over the same geographic area.
Vertical accuracy is verified by comparison of points from the calibration flights to conventionally surveyed ground points at the calibration site.
Control point used to build GPS network from which positions of kinematic GPS solution and calibration points were derived. NAD83 published coordinates are Lat: 53 58 11.3379, Long: -101 10 32.3736, Ellipsoid Height: 237.54m. This point was occupied during kinematic GPS collection.
Kinematic GPS data was processed using published coordinates. Kinematic GPS and inertial information were combined to create the final position and attitude trajectory. The position and attitude trajectory was combined with data from the scanning laser to produce a raw XYZ point cloud.
250, 3115 12th Street NE
Overlapping flight lines were compared at the calibration site and within the project area to determine the boresight corrections required to remove systematic errors. Raw point clouds were generated using the attitude information and scanning laser ranges.
250, 3115 12th Street NE
Raw XYZ point clouds were combined and divided into 500m x 500m tiles. Redundant data between overlapping flightlines was removed.
#250, 3115 12th Street NE
An automatic ground classification routine was run on the LiDAR data using TerraScan, and the results were verified by viewing a shaded relief model. Points that existed above ground were classified to vegetation and then buildings were classified manually from the vegetation points using the shaded relief model to identify them. Points that could not be identified as vegetation or ground were classified as non-ground; bridges and transmission lines were classified to non-ground.
250, 3115 12th Street NE
LiDAR data was adjusted from ellipsoid to orthometric elevation using the CGVD28 height model.
#250, 3115 12th Street NE
A gridded ASCII XYZ file with a horizontal spacing of 1m was created. Elevations were derived from triangle facets in the TIN model (built using ground points only) at the centre of the grid cell.
#250, 3115 12th Street NE
A surface was created from the ground, vegetation, building, and non-ground points in TerraScan, and a gridded ASCII XYZ file with a horizontal spacing of 1m was created. Elevations were derived from the highest point elevation within the grid cell.
#250, 3115 12th Street NE
Metadata imported.
copied compressed .gz files to local disk unzipped using 7 ZIP created a grid from the first text file to be used as the snap grid CREATETIN GENERATE (TEXTFILE) POINT TINARC POINTGRID ran aml called ld_lidar_grid to generate grids from all text files used mosaic to new grid in arcgis toolbox 9.2 used 32 bit float 1.0 metre cell mean used con(isnull (lidar), focalmean(lidar, rectangle, 3, 3,), lidar) to fill in gaps between the tiles of data. The Pas bare earth grids were successfully created.
The only attributes assigned were point classification during the processing phase using TerraScan. See process steps for details.
None
250, 3115 12th Street NE