Corrections to aircraft pressure level radiances (incl. jacobians)

[BenjaminTJohnson]

Recent studies from NASA colleagues have identified issues with radiances produced at aircraft altitudes.

(1) Under certain circumstances, the radiances produced are either unexpectedly different or behave like clear-sky radiances.

(2) The jacobians produced for aircraft are exactly the same as TOA radiance jacobians. This is because there's no aircraft-specific codes in the TL/AD/K_Matrix code in CRTM. This is problematic for DA using aircraft data, as it will produce incorrect jacobians.

Conversation with NOAA STAR colleagues suggests that there's a fundamental issue with the current aircraft implemenation.
See attachment.
Introduction_to_CRTM_solver.pdf

Code changes to be provided by Q. Liu. This issue will be updated when the code has been committed to the CRTM repository (initially v2.4.0, but will be quickly ported to CRTM v3.x).