Bug Status: Fixed

There is a minor bug which can affect cases with profile interpolation when apply_reg_limits is TRUE and the surface lies above the bottom of the input profile: it is possible that the regression limits are not applied to the coefficient level(s) just below the surface. These levels can contribute to the interpolated optical depths, and this may impact the TOA radiance. Whether this bug has any effect on radiances depends on the relative positions of the coefficient and user levels with respect to the surface pressure. To have an effect the input profile must also fall outside the regression limits in the near-surface levels. For cases where this does have an impact on TOA radiances, the size of the impact depends on how far beyond the regression limits the input profile variables are. However, the impact on BT would typically not be more than a few hundredths of a Kelvin for surface-sensitive channels. The coefficient regression limits can be seen in these tables.

A code fix is available which also includes the bug fix dated 13/10/2014 below: download this gzipped tar file, extract in the src/main/ directory and recompile RTTOV.