Aerial Imagery and Terrain Modeling
FAA Approved Unmanned Aircraft Technology
In this test we refined our collection and processing methodologies. The testing validated the georegistration precision of AeroLogix GIS imagery mosaicking. We purposely chose testing points in the outer extremes of the area as their distances from our ground control points would reveal greater errors. The entire collection aligned perfectly with existing GIS imagery and shapefiles.
In this test, the GeoStar UAV collected a 0.5sm x 0.5sm area (160 acres) from an altitude of 550ft AGL achieving a Ground Sample Distance (GSD) of approximately 3.0cm per pixel. Six ground control targets were placed across the collection area and their positions were incorporated into the imagery processing. After AeroLogix processed the imagery into georegistered mosaic tiles, the Le Sueur County Surveyor shot 3 new “Control Point” positions with a RTK survey GPS along the roads that define the outer perimeter of the collection area. The Control Points were the corners of stripes painted on the roads. The precise positions and elevations were recorded and then converted to a GIS shapefile that allowed their actual positions to be compared against the reported positions in the AeroLogix mosaic tiles. The shapefile control points are depicted as a red “X” overlaying the mosaic tile imagery.
The geo-registration accuracy was determined to be a remarkable 0.5-3.3 INCHES Horizontal and 0.5-1.5 INCHES Vertical!
See the results below!
(Please keep in mind the pictures are low-resolution screen captures for web display. Actual AeroLogix imagery is much higher resolution)
25 NOVEMBER 2014 GEO-REGISTRATION EVALUATION - Le Sueur County, MN