Geometric Quality Testing of the WorldView-2 Image Data Acquired over the JRC Maussane Test Site using ERDAS LPS, PCI Geomatics and Keystone digital photogrammetry software packages - Inital Findings
This report presents the geometric quality results recorded for the five samples of the WorldView-2 Basic and Standard (processing level 1A and 2A) imagery acquired over the JRC Maussane Test Site. Different mathematical models of the WV2 sensor were tested, i.e. RPC-based and rigorous models implemented into PCI Geomatics, Keystone Spacemetric, and ERDAS IMAGINE& LPS software based on the following auxiliary data:
- several configurations (eg. 9, 6, 4) of equally distributed GCPs of 0.1m<RMSEx,y,z<0.6m;
- DEM of 2m grid and RMSEz=0.6m;
- 12 well-distributed independent check points (ICPs) of RMSEx,y,z<0.6m.
The preliminary results of the analysis show that the 1-D RMSE of the WV2 image characterised by large off-nadir angle, i.e. greater than 30 degrees (or elevation angle less than 56 deg) is close to or below the 2.5m EU acceptable threshold.
Further testing is required, especially for less accurate DTM data, diverse terrains and images characterised by high satellite inclination angle.
Consequently, this report recommends that at least 6 (or 9 in areas with terrain slope diversity or high off-nadir angle) well-distributed ground control points during the WV2 sensor modelling phase using the Rational Functions mathematical model should be used. The rigorous model requires a minimum 9 or more ground control points. Accuracy requirements for auxiliary date, i.e. ground control points and DEM, given in ¿Guidelines for Best Practice and Quality Checking of Ortho Imagery¿ should be strictly followed.JRC.DG.G.3-Monitoring agricultural resource
