Data format: Raster Dataset - GRID
File or table name: e854_sc
Coordinate system: Universal Transverse Mercator
Theme keywords: DEM, elevation, LiDAR, surface elevation, topography, hypsography, DSM
| Sturgeon Creek 1m LiDAR Grid | |
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Data format: Raster Dataset - GRID File or table name: e854_sc Coordinate system: Universal Transverse Mercator Theme keywords: DEM, elevation, LiDAR, surface elevation, topography, hypsography, DSM |
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Abstract:
The Sturgeon Creek LiDAR data is a raster layer in ArcInfo grid format. The raster is a 1m grid representing elevation. |
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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.
The Sturgeon Creek LiDAR data is a raster layer in ArcInfo grid format. The raster is a 1m grid representing elevation.
To provide a very accurate DEM of the Sturgeon Creek area.
Fugro Horizon's, Inc. LiDAR Acquisition/Processing/Quality Control 08-0699 Red River Basin Manitoba LiDAR Acquisition LiDAR acquisition for this project was collected with Leica ALS50 #64 LiDAR systems including an inertial measuring unit (IMU) and a dual frequency GPS receiver. Acquisition was accomplished on 5/06/09 - 5/23/09. The LiDAR flight specifications follow: Field of View: 45 Degrees Altitude: 8000 feet AMT Scan Rate: 33.1 Hz Pulse Rate: 93.8 kHz Airspeed: 165 knots Average Post Spacing: 1.7 meters Average Swath Width: 2050 feet Intensity Mode: 12+3 Total Flight Lines: 47 Number of Lifts: 4 GPS Data Collection A GPS receiver was in constant operation over a temporary control point during flight acquisition. The base station identification and location are listed below. Station Location CYWG 49 53 35.87063 -97 13 51.76728 206.5690 CJB3 49 33 20.65837 -96 41 06.36711 229.5010 CJA3 49 12 27.67021 -98 03 19.82268 265.2460 CYPG 49 55 01.49520 -98 16 46.33718 237.6450 KDVL 48 06 43.86554 -98 54 27.33776 415.7050 GPS Data Processing All GPS phase data was post processed with continuous kinematic survey techniques using "On the Fly" (OTF) integer ambiguity resolution. The GPS data was processed with forward and reverse processing algorithms. The results from each process, using the data collected at the airport, were combined to yield a single fixed integer phase differential solution of the aircraft trajectory. The differences between the forward to reverse solution within the project area were within project specifications (<10cm) in both the horizontal and vertical components, indicating a valid and accurate solution. IMU Data Processing An IMU was used to record precise changes in position and orientation of the LIDAR scanner at a rate of 200 Hz. All IMU data was processed post flight with a filter to integrate inertial measurements and precise phase differential GPS positions. The resulting solution contains geodetic position, omega, phi, kappa, and time for subsequent merging with the laser ranging information. LiDAR Data Processing LIDAR Data Preprocess. Flight Line Data Acquisition/Quality Control Check: LiDAR data and the IMU files were processed together using LIDAR processing software. The data set for each flight line was checked for project area coverage, data gaps between overlapping flight lines, and tension/compression areas (areas where data points are more or less dense than the average project specified post spacing). Based on this check it appears the entire project area is covered without gaps. Boresighting Process: Pre-processing of LiDAR corrects for rotational, atmospheric, and elevation differences that are inherent to LiDAR data sets. This process is called boresighting. LiDAR data was collected for bi- and cross-directional flight lines over the airport prior to and after acquisition of the project area. Using an iterative process that involves analyzing raster difference calculations the Omega, Phi, Kappa angle corrections of the LiDAR instrument were determined. The corrections were applied to the LiDAR data set for the project area. Vertical Accuracy Check: Extensive comparisons were made of vertical and horizontal positional differences between points common to two or more LiDAR flight lines. This was done for the airport bore-sight testing area and the project area. All flight lines (airport and project) were within project specifications for vertical accuracy. LiDAR Intensity Check: An intensity raster for each flight line was generated. The raster was checked and verified that intensity was recorded for each LiDAR point. Project Coordinate System: LiDAR preprocessing software outputs data to its corresponding UTM zone in meters and a GRS80 ellipsoidal height. Vertical Bias Correction: LiDAR has a consistent vertical offset. LiDAR ground points were compared to independently surveyed and positioned ground control points at both the airport bore-sight area and the project area. Based on the results of these comparisons, the LiDAR data was vertically biased down to the ground. Project Ground Control Check: Comparisons between on-site ground survey control points and LiDAR data yielded the following results: Vertical Accuracy (RMSE): 0.036 Standard Deviation: 0.037 Mean Difference: 0.006 Number of Points: 11 LiDAR Data Surfacing Process. Raw LiDAR Data Set: LiDAR data in overlap areas of project flight lines was removed and data from all swaths was merged into a single data set. The data set was trimmed to the digital project boundary including an additional buffer zone (buffer zone assures adequate contour generation from the DEM). Resulting data set is the Raw LiDAR data. The Raw LiDAR data set was processed through a minimum block mean algorithm and points were classified as either bare earth or non-bare earth. User developed "macros" that factor mean terrain angle and height from the ground, were used to determine bare earth point classification. LiDAR Surfacing Process: The surfacing process is a 2D-edit procedure that ensures the accuracy of the automated feature classification. Editors used a combination of imagery, intensity of the LiDAR reflection and tin-editing software to assess points. The resulting data set is 2D Surfaced Bare Earth. The LiDAR data is filtered using a quadric error metric to remove redundant points. This method leaves points where there is a change in the slope of surfaces (road ditches) and eliminates points from evenly sloped terrain (flat field) where the points do not affect the TIN LiDAR data. The resulting data set is 2D Surfaced/Filtered Bare Earth LiDAR Data 3D Edit Process. LiDAR 3D Edit Process: The 2D surfaced/filtered bare-earth LiDAR data and stereo imagery are edited in softcopy photogrammetric workstations with 3D viewing and compilation capabilities. Contours generated from the LiDAR data were compared to the imagery. Breakline features (as necessary to generate accurate contours), water features and planimetric data were collected. Data points still present on structures and/or vegetation were removed. LiDAR data erroneously removed during the surfacing process was replaced. LiDAR points required as spot elevations are classified. Resulting data set is 3D Bare Earth LiDAR. LIDAR Graphic Edit Process: Contours were generated from the 3D linework and bare-earth LiDAR data and reviewed by experienced graphics edit technicians. LiDAR points that create small "tops and depressions" are removed from the data set. Anomalies in the data set were corrected in the TIN at the softcopy photogrammetric workstations. 3D linework was reviewed for uniformity and completeness. Water bodies (i.e. streams and lakes) were analyzed for proper elevations and flow characteristics. LiDAR points located within the water feature boundaries are removed (LiDAR does not accurately measure water surface elevations). The resulting data set is the Digital Terrain Model data used to generate the final contours - DTM data includes 3D breaklines and filtered LiDAR data.
ground condition
none
3600 Jet Drive
This data set was developed for the Province of Manitoba by Fugro Horizons Inc.
N/A
Fugro Horizons Inc. compared on-site ground survey control points and LiDAR data: Vertical Accuracy (RMSE) 0.036 Standard Deviation 0.037 Mean Difference 0.006 Number of Points 11
Dataset Conversion: Converted a geodatabase raster catalog accessing bare earth floating point grids to a raster dataset within the geodatabase. Exported the raster to ArcInfo GRID format.
200 Saulteaux Crescent
Vertical Accuracy Verification: Vertical accuracy was verified by calculating the difference between 7532 GPS points provided by Manitoba Infrastructure and Transportation (MIT) and LiDAR closest bare earth points. Calculations showed that 99.3% of differences were within 15cm and 100% of differences were within 30cm.
200 Saulteaux Crescent
200 Saulteaux Crescent
200 Saulteaux Crescent