RTTOV missing values are different than ours, so don't let them get in
The problem is surface emissivity (when running with RTTOV) is set in two stages.
- Get land emissivity from RTTOV atlas
a. This actually fills the emissivity with RTTOV missing values (-127?) over ocean - fill ocean using constant value based on surface type.
a. surface type is from ancil hdf file, a different source.
b. sometimes RTTOV atlas says "location is ocean, no emissivity data" and surface type says "location is land, skipping fill with constant value". so no surface emissivity - before this commit, the value that would end up in the output was the RTTOV missing value, which wouldn't be recognized as missing because RTTOV uses -127 or something that's not -999.0