Skipping problematic profiles

[Amirhossein Nikfal]

Hi,

Some of the profiles in my prof.dat file cannot be used for simulation (due to zenith angle > 75, etc). Before running the program, is it possible to set it up to skip those problematic profiles? So the program will not be terminated and the output for those profiles will be written as missing values.

Regards,
Amir

[James Hocking]

Hi Amir,

If you are simulating one profile at a time then within the loop that reads the profiles and runs RTTOV you can put a check on the zenith angle and if it exceeds 75 degrees then skip the call to RTTOV for that profile (e.g. “cycle” the loop before calling RTTOV). If you want to run additional checks on the profile in addition to zenith angle you can use the rttov_user_profile_checkinput subroutine (see Annex N of the user guide and section 7.3 (page 46 in the RTTOV v13.2 user guide) to screen out problematic profiles.

If you are simulating multiple profiles in each call to RTTOV you can manage it in a similar way, for example, read in the profile data and run a check: if the profile is bad, then do not call RTTOV and “cycle” the loop without increasing the profile index so that the next profile to be read in overwrites the bad profile.

As a general point (and as noted in the RTTOV documentation), the “prof.dat” input file is intended as a human-readable way of demonstrating how to run RTTOV. It is common and recommended to change the example code to read profile data from whatever source file format it comes in rather than having to get it into this custom ASCII file format. I recommend considering this for your application if you are simulating many profiles.

Best wishes,
James

[Author]

Posts