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10.11 Incomplete Looking Raster Maps

This caveat comes from the investigation of PHT-P raster maps:

Caveat: If the flux on the detector is small, close to zero or even negative signals can occur at the end of the DERIVE_SPD processing stage. The signals are flagged `zero signal for plateau' (see Table 13.3). OLP 10 does not continue to process these flagged data in DERIVE_AAR, see Section 13.3 for SPD product types. This leads to PGAI map products which look apparently incomplete. The most likely observations that are affected involve the short wavelength filters of PHT-P1 (where the sky background is low) in combination with small aperture sizes.

ISO Handbook Volume IV (PHT), Version 2.0.1, SAI/1999-069/Dc