Algorithm Specification

Algorithm Specification

This tool parses an (A)ATSR(-1/2_ ATS_TOA_1P product, then for each pixel in the Nadir and Forward views:

1. Computes the original geolocation of the measurement (UBT) using methodology taken from a Technical Note by Andrew Birks of Rutherford Appelton Laboratory - Instrument Pixel Coordinates and Measurement Times from AATSR Products - and methodology extracted from the AATSR Frequently Asked Questions (FAQ) document "Appendix A Interpolations of pixel geolocation in AATSR full resolution products" .
2. Computes the acquisition time of the pixels using the Andrew Birks TN. This methodology allows retrieval of the acquisition time on a pixel basis as opposed to the usual per scan basis. Note that there appears to be a systematic bias of +0.15 seconds in the acquisition time retrieval. This is hinted at in the Andrew Birks TN.