TerraSAR-X orbital accuracy and precise radar metrics enable space-based Ground Control Point Collection World-Wide
CompassData offers Remotely Sensed Ground Control Points (RSGCP™), providing control for those areas that are too remote, or too dangerous, for field data collection crews to go in person or where on-ground GNSS surveys are not possible.
The Remotely-Sensed GCP data are delivered to the customer in the same fashion as CompassData terrestrial GNSS control points, including:
- An Image Chip corresponding to the SAR Image Chip for the control point
- Metadata file in CSV format
- SHAPE file for the Area of Interest
- KML file for viewing in Google Earth™
- An Accuracy Report and a Site Sketch providing additional details regarding the RSGCPs
To complement CompassData’s archive of terrestrial GNSS collected GCPs, we are working with Infoterra GmbH, as an authorized re-seller, using the new Synthetic Aperture Radar (SAR) sensor technology, combined with an extremely precise on-orbit platform.
Although GCPs collected by terrestrial means typically offer higher accuracies, this spaceborne approach is a significant milestone in control.
This is possible through:
- A very high degree of orbital accuracy of the TerraSAR-X satellite, (residing in the centimeter range)
- Very precise radar beam tracing
- Extremely high-resolution capabilities of the satellite and the resulting high geolocation accuracy of the SAR imagery (<1m in Range and Azimuth for two collection modes)
The sensor is highly suited for collecting precise and accurate 3D ground information regardless of whether or daylight conditions.
Infoterra follows the accuracy standards established by CompassData Inc. to provide data collection in two standard offerings:
- RS-1 Precision: Based on 3-4 High-Resolution SpotLight scenes, 5 GCPs at <=1m accuracy can be generated within an area of 20 km2
- RS-2 Precision: Based on 2 StripMap scenes, 8 GCPs at <=3m accuracy can be generated within an area of 1,000 km2