8.20. PeruSat-1

PeruSat-1 provides exact linescan camera models and RPC-approximated camera models in separate files. The names for these start with “DIM” and “RPC”, respectively, and end with “.XML”.

If desired to use the exact model, the stereo command is:

parallel_stereo -t perusat --stereo-algorithm asp_mgm \
    left.tif right.tif left.xml right.xml results/run

For the RPC model the option -t rpc should be used and the correct camera files should be passed in. See also Section 8.19.

If the -t option is not specified, it will be auto-guessed based on the content of the camera files provided as inputs.

For PeruSat-1 exact linescan camera models the atmospheric correction and velocity aberration corrections ([NC66]) are disabled, as these decrease somewhat the agreement with the RPC models.

DEMs created with the exact and RPC models differ by a systematic vertical shift of about 15 meters for unknown reasons, even though the intersection error maps are very similar. Nothing in the sensor manual or camera metadata suggests the cause of this. The pc_align tool can be used to reduce this discrepancy. The mean absolute difference of the (full-image extent) aligned DEMs is about 0.17 meters.

See Section 6 for a discussion about various speed-vs-quality choices.