1. Using free and/or open source tools to build workflows to manipulate and process LiDAR data Christopher Crosby

2. Point cloud filtering (classification)

3. Software options for point cloud filtering: ALDPAT - http://mitigation.fiu.edu/lidartool.htmlhttp://mitigation.fiu.edu/lidartool.html –Open source option for full LiDAR workflow: Task 1. Split Tape Files into Strips Task 2. Separate First and Last Return Measurements from a 9 Column Strip File Task 3. Convert ellipsoid to orthometric heights Task 4. Estimate strip boundary Task 5. Merge Boundary Files Task 6. Create Shape File Task 7. Tile Strips Task 8. Filter LIDAR Points Task 9. Gridding Tiles Task 10. Convert Surfer Grids to ArcGIS Grids Miscellaneous Tasks Very linear – output of one task is input for following task

4. ALDPAT filtering algorithms Elevation Threshold with Expand Window (ETEW) Progressive Morphology (PM) 2D Morphological Filters (Square or Circle Window Maximum Local Slope (MLS) Iterative Polynomial Fitting (IPF) Polynomial Two-Surface Filter Adaptive TIN (ATIN) Refer to users guide for description and parameters for each

5. Software options for point cloud filtering: ArcGIS 3 rd Party Extensions: Qcoherent LP360 - http://www.qcoherent.com/http://www.qcoherent.com/ VLS LiDAR Analyst - http://www.featureanalyst.com/lidar_analyst.htm http://www.featureanalyst.com/lidar_analyst.htm ~ $1k / seat (academic) Industrial Solution: TerraSolid Software suite - http://www.terrasolid.fi/en/products/4 http://www.terrasolid.fi/en/products/4 $10k - 30k depending upon bundle

6. Game plan Convert LAS point data to ASCII - LASTools Grid ASCII points – Points2Grid –Experiment with search radius and gridding parameters Visualize results – ArcGIS or Global Mapper Grid file format conversions and projection - GDAL

7. Tools: LasTools (point cloud format conversions) GEON Points2Grid (DEM generation) GDAL w/ discussion of EPSG (Raster data conversion and projection) * ALDPAT (point cloud filtering) – time and complexity doesn’t permit full discussion

8. MS-DOS Commands… Run > “cmd” to get command line window Basic Navigation: cd directory - go into directory cd.. - up a directory cd../.. – up two directories dir to list contents of a directory help command - lists flags and usage exit - … TAB – auto complete

9. LAStools http://www.cs.unc.edu/~isenburg/lastools/ Martin Isenburg, Jonathan Shewchuk - UNC “converting, viewing, and compressing LIDAR data in LAS format” MS-DOS command line tools

10. GEON Points2Grid Desktop application to generate DEMs and shot density plots from LiDAR point cloud data. Same algorithm as available in the GEON LiDAR Workflow system online Algorithm by Han Kim (UCSD) Windows implementation by Newton Alex (ASU)

11. http://lidar.asu.edu/points2grid.html

12. GDAL - Geospatial Data Abstraction Library “is a translator library for raster geospatial data formats that is released under an X/MIT style Open Source license by the Open Source Geospatial Foundation” http://www.gdal.org/ Very powerful tool for raster file conversions and projection. Available for Linux, Mac, Windows Recommend installing full FWTools package which includes GDAL: http://fwtools.maptools.org/ http://fwtools.maptools.org/ –Open Source GIS Binary Kit for Windows and Linux

13. EPSG Numeric codes that refer to a specific coordinate system. Used by software such as GDAL to define projection. http://spatialreference.org/

14. http://lidar.asu.edu/LViz.html