In the adjustment, three parameters were determined simultaneously for all 3631 scenes: translations in Northing and Easting and a rotation. The internal scene geometry, as depicted in the header data included in the full resolution products produced by NASDA (level 2.1), was preserved.
A total of 62245 tie points in the overlap areas between the scenes were measured using image correlation. The residual mean square error (RMSE) of the tie point observations was 36.5 metres in Northing and 33.6 metres in Easting, with maximum errors of 337.7 m and 338.7 m, respectively.
The RMSE of the scene translations - as compared with the scene center locations given in the header files of the original level 2.1 data - was 242.1 m in Northing, 317.7 m in Easting for the mosaic contained on this CD-ROM. The average difference in scene translations between the mosaics from the two seasons was -21.1 m in Northing and 283.3 m in Easting.
Note that the figures above describe the internal geometric consistency of the data set. In absolute terms, discrepancies of up to several kilometres have been observed when comparing the locations of mosaic coast lines to some digital map material. Absolutely corrected versions of all mosaics will be featured on the AFR2 CD-ROM.
In conclusion, the relative, or internal, geometry of the current mosaic is at subpixel level, while the absolute geometry may be several kilometres off in parts of the mosaic area.