Continental Mapping has held two consecutive contracts to collect satellite imagery and provide orthorectification services for 150 airports throughout the Middle East and Central Asia.
In 2011, an award was made by the US Air Force Central Command (AFCENT) to Continental Mapping to collect 10,000 sq km of imagery (100 areas of interest or AOI) twice over two years
In 2014 a follow-on award was made to Continental Mapping to collect 15,000 sq km of imagery (150 AOIs) twice over two years. AOIs were centered over airfields and the minimum AOI per unique collection was 10km by 10km.
Parameters used to determine the feasibility of satellite tasking during the project timeframe were as specified:
- ≤17 degrees off nadir
- 0% cloud cover over airfield
- ≤10% cloud cover within installation boundary
- ≤20% cloud cover for the rest of the AOI
- Free of snow over 75% of the AOI
AOIs across AFCENT’s region, many sites had to be collected multiple times to meet project parameters. Continental Mapping leveraged our relationships with commercial satellite providers to obtain 8-bit, ≥ 60 centimeter resolution, 3-band pan sharpened ortho-ready imagery. Continental Mapping then obtained various sources of ground control to achieve the necessary accuracy, obtained available DEMs for each unique collection and orthorectified the imagery.
Deliverables consisted of 3-band pan-sharpened natural color orthomosaics in both GeoTIFF and a lossy MrSID Generation 3 format with associated world files. The MrSID had a 20:1 compression ratio. Positional accuracy had a root mean squared error of less than 4 meters. All of the imagery was delivered in WGS84 datum and projected in the appropriate UTM zone.
The imagery was 8-bit, better than 60cm resolution, 3-band pan sharpened. Continental Mapping sought and used existing sources for the ground control to achieve the needed accuracies and obtained and used various DEMs to support the orthorectification process. The project received excellent reviews from AFCENT staff.