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WAM developed a unique approach to meet the needs of the US Army Corps of Engineers-Kansas City District; to map the Digital Multipurpose Training Range (DMPTR), Multipurpose Range Complex (MPRC), and Screening Range. Special requirements included schedule, accuracy and avoidance of unexploded ordinances in the project area.
To meet planned design and construction schedules, aerial acquisition was done in July during full leaf-on vegetation. Tall prairie grass (6 to 8 foot) obscuring the terrain. The risk of unexploded ordinance (UXO) prohibited a traditional ground topo survey to supplement the photogrammetric mapping. To meet the design accuracy requirement of 1' contours and line-of-sight visualization for range targeting systems, WAM choose the use of LiDAR for capturing the terrain elevation.
Aerial photography with ABGPS and IMU was flown during the daytime. LiDAR flights were flown at nighttime under close coordination with Range Control at Ft. Riley within a 24 hour period to minimize disruption to the DMPTR and MPRC schedules.
WAM performed all photogrammetric tasks (AT, mapping & orthos) using digital softcopy workstations. WAM also performed a 100% QC verification internally using TerraScan software for the "bald earth" LiDAR surface model produced by subcontractor LandAir.
A unique quality control plan (QCP) used 188 ground check points (GCP) surveyed in areas safe from UXO's; including locations of underground utilities, wells, culverts, manholes, and other features field surveyed
Statistically, 90% of elevation differences between LIDAR shots and GCPs were less than 6', a
RMSE of 0.328' for the entire dataset; complying with the VMAS standard for 1-foot contour
mapping. By isolating the 10% outliers, the RMSE drops to 0.228 feet, meeting NSSDA standards,
which indicates a very good overall topographic accuracy of the dataset.
