L1C Software

• Introduction
• Running L1C
• Example
• Updates

30OCT07

This page describes the L1C software versions 23MAY05 and later, which create L1C format 2.0 files required for input to MORSE v3. Documentation for the earlier versions of L1C is here.

The main program l1c.pro and associated procedures l1c_*.pro are available as a compressed tar file: l1c_30OCT07.tar.gz
Note that the main program contains a !PATH = ... statement which should be edited to point to the directory where the other modules are stored unless all in the local directory.

Part of the new L1C format requires the addition of 'nominal' tangent altitudes to each sweep as well as the actual altitudes. However, the L1B data contains no equivalent information so at the moment the l1c.pro has hard-wired altitudes dependent on the number of sweeps in the file which works for both the 17 (up to Aug04) and 27 (Jan05 onwards) nominal modes but not for the various special modes which have also been used (although in principle these could also be added).

There is also a separate IDL procedure read_l1c.pro which can be used to read in L1C data into a structure, with the microwindow information conveniently sorted.

Running L1C

L1B file:

Enter name of the MIPAS L1B file.

Note that the entered response is saved in a local file l1c_l1bfil.save, so if the program is run subsequently the prompt will be L1B file [<CR>= use l1c_l1bfil.save]: and the user has the option of hitting the carriage return to reuse the same filename.

Microwindow list [=none]:

Enter the name of the file containing the list of required microwindows.

See MORSE inputs for definition of an input .lst file.

The file format allows several such files to be simply appended, eg mwlist.lst, which contains the pT and H2O microwindows used for generating the sample data in the MORSE distribution file. The absorber indices (following the altitude ranges) are not read by l1c.pro.

If the user types carriage return, no apodisation is performed and the output will simply contain a list of scan/sweep headers (which may be useful for examining the locations of L1B spectra).

First,Last Scan Nos [=1, 72]: (where eg 72 is the number of scans in the L1B file)

Enter the first and last scan numbers required for processing, separated by a space or a comma.

If carriage return is typed, all scans within the L1C file are processed.

Scans containing a different number of sweeps to the nominal number are skipped.

Outputs are written to files L1C_ooooo_SCAN#ss where ooooo is the Absolute Orbit Number and ss is the scan number, eg L1C_02081_SCAN#13 (as used in the MORSE distribution file).

Example

IDL> .run l1c
% Compiled module: $MAIN$.
L1B file: MIP_NL__1P020724_112130_oldNL_M3_2081_020918 
or L1B file [= use l1c_l1bfil.save]:
% Compiled module: L1C_INPMPH.
% Compiled module: L1C_INPSPH.
% Compiled module: L1C_INPMIC.
Microwindow list [=none]: mwlist.lst
% Compiled module: L1C_NBFAC.
First,Last Scan Nos [=1, 72]: 13 13
% Compiled module: L1C_INPSCAN.
I-L1C: Processing Scan#      13
I-L1C: Creating File L1C_02081_SCAN#13
% Compiled module: L1C_WRTHDR.
% Compiled module: L1C_SWPTIM.
% Compiled module: L1C_INPMDS.
% Compiled module: L1C_SWPMIC.
% Compiled module: L1C_CLDIDX.
% Compiled module: MEAN.
% Compiled module: MOMENT.
% Compiled module: L1C_APOD.
% Compiled module: REVERSE.
% Compiled module: L1C_CLDRAD.
% Compiled module: L1C_WRTSWP.
% Compiled module: L1C_TIME.
% Compiled module: CALDAT.
% Compiled module: L1C_SZALST.
% Compiled module: L1C_MICNOI.
% Compiled module: L1C_WRTMIC.
IDL>

Updates

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