5. Some practice

It's time to do some practice. Here is an example of how to use cookie-cutter

Before going on, you should have built and configured the package.

1) Look for an EUMETSAT archive directory (with compressed files). It should contain files like these:


[user@hostname EUMETSAT-ARCHIVE]$ ls
[...]
/path/to/seviri_data/H-000-MSG1__-MSG1________-_________-PRO______-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000001___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000002___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000003___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000004___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000005___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000006___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000007___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000008___-200506011200-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-_________-EPI______-200506011200-C_
[...]

2) catslot one day of the directory content into another directory (see appendix A for a brief description of the command catslot and the SATMOS archive format):


[user@hostname cookie-cutter]$ catslot EUMETSAT-ARCHIVE SATMOS-20050601 20050601
[user@hostname cookie-cutter]$ cd SATMOS-20050601
[user@hostname SATMOS-20050601]$ ls
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010000
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010015
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010030
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010045
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010100
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010115
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010130
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010145
H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506010200
[...]
Of course, the previous steps are in no way necessary if your MSG data were provided by the SATMOS archive center.

3) get (or produce) a text file containing node times and longitudes for this day. We'll call it nodes_20050601.txt:


2005-06-01 01:07:50     184.1
2005-06-01 02:46:43     159.38
2005-06-01 04:25:36     134.66
2005-06-01 06:04:29     109.94
2005-06-01 07:43:23     85.22
2005-06-01 09:22:16     60.5
2005-06-01 11:01:09     35.78
2005-06-01 12:40:02     11.06
2005-06-01 14:18:55     346.34
2005-06-01 15:57:48     321.62
2005-06-01 17:36:41     296.9
2005-06-01 19:15:34     272.18
2005-06-01 20:54:27     247.46
2005-06-01 22:33:20     222.74

4) Find the following orbital parameters of the chosen sun-synchronous orbit: inclination (we'll take 98.2° in this example) and orbital period (we'll take 98.88 minutes).

5) Choose a width of extraction (in degrees of longitude at the equator). We'll take 10°.

6) Run the command:


[user@hostname cookie-cutter]$ cookie-cutter -i 98.2 -T 98.88 -w 10 \
      nodes_20050601.txt SATMOS-20050601 output_file

The last argument is the name of the file which will be created by cookie-cutter. In fact, two files will be produced: output_file.hdf and output_file.ppm. The first one is a standard HDF file and the other one is an image in ppm format.