A. EUMETSAT and SATMOS archive formats, and how to convert them

EUMETSAT provides MSG1/SEVIRI data in XRIT format. Data are available each 15 minutes, in 8 segments for low-resolution channels and 24 segments for the high-resolution channel.

For example, here is all the files associated to the SEVIRI channel IR_016, for the slot 11:45 on 22th june 2005. PRO is for 'PROLOGUE', EPI is for 'EPILOGUE'. Prologue and Epilogue files are common to all the channels.


[user@hostname EUMETSAT-ARCHIVE]$ 
[...]
/path/to/seviri_data/H-000-MSG1__-MSG1________-_________-PRO______-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000001___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000002___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000003___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000004___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000005___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000006___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000007___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-IR_016___-000008___-200506221145-C_
/path/to/seviri_data/H-000-MSG1__-MSG1________-_________-EPI______-200506221145-C_
[...]

Now imagine that there are 11 SEVIRI low-resolution channels and 1 high-resolution channel. This gives 114 files by 15 minutes, or about 11000 files by day.

cookie-cutter can't operate on separate segments. All the segments of the same slot (same hour) must be grouped together, with the Prologue and Epilogue files, before any processing by cookie-cutter. The operation is quite simple. You'll have to decompress all the files with xRITDecompress (a command provided with EUMETSAT), then to cat them in the order :

prologue
image segments
epilogue

The output must be given the following name (in the present case):


H-000-MSG1__-MSG1________-IR016____-CYCLE____-200506221145

The number of files is reduced by nearly 8. This is the SATMOS archive format, from the SATMOS archive center at Lannion. Be aware that the underscore in the original channel name (IR_016) is still present, but has been moved after the name (IR016_).

The cookie-cutter suite provides a small command catslot which does all this nasty job for you. Suppose you've got EUMETSAT data files in a directory EUMETSAT-ARCHIVE. To have them processed by cookie-cutter, you'll need to convert them into the SATMOS archive format, in a directory, let's say, of name SATMOS-YYYYMMDD:


[user@hostname cookie-cutter]$ catslot EUMETSAT-ARCHIVE SATMOS-20050622 20050622
[user@hostname cookie-cutter]$ catslot EUMETSAT-ARCHIVE SATMOS-20050622 20050622 1145
[user@hostname cookie-cutter]$ catslot EUMETSAT-ARCHIVE SATMOS-20050622 20050622 1145 1900

In the first command, all files from 22th june 2005 in EUMETSAT-ARCHIVE will be concatened into SATMOS files in SATMOS-20050622. The two other commands show how to convert only some slots (you may specify one slot, or a range of slots)

cookie-cutter is ready to process all the files in SATMOS-20050622.

Warning

In order to work, catslot supposes that xRITDecompress is available in your PATH. You won't find xRITDecompress in the cookie-cutter suite, you'll have to get it from EUMETSAT.