Format of the PP-record metadata files (-summary.txt and –details.txt)
----------------------------------------------------------------------

Two simple pp-record metadata files are provided alongside each pp-file. 

The purpose of these files is to provide a basic description of the contents
of each 2-dimensional pp-field within each file. 

The "summary" (-summary.txt) and the "details" (-details.txt) files have the 
same basic format:

 * First header line:  start and end date/times
 * Second header line: column headers
 * Record lines:       there is a record line for each pp-field in the file,
                       the values relate to the column headers
 * Last line:          shows how many pp-field are in the file
 
The "summary" file is simpler as it contains less columns than the "details" file.

The column descriptions are listed below for both metadata file types ("summary"
and "details" files). Note that the official pp-documented header names and position
in the header file are shown in brackets where appropriate.

 START Y M D h m:      Start date/time. Header words 1-5. Printed as a zero-filled
                       12 digit integer with heading "   Y M D h m".

 END Y M D h m:        End date/time. Header words 7-11. Printed as a zero-filled
                       12 digit integer with heading "   Y M D h m".

 PROC:                 (LBPROC), header word 25. Processing code.

 STASH:                (LBUSER(4)), header word 42. Stash code.

 EXP:                  (LBEXP), header word 28. Experiment identification.
                       Decoded and printed as a 5 character string.

 LREC:                 (LBLREC), header word 15. Length of data record.

 LBLEV:                (LBLEV), header word 33, fields file level code.

 LEV:                  (BLEV), header word 52. Level.

 HLEV:                 (BHLEV), header word 54. A or C value of level.

 LAT:                  (BPLAT), header word 56. Latitude of pole of
                       projection.

 LON:                  (BPLON), header word 57. Longitude of pole of
                       projection.

 NPT                   (LBNPT), header word 19. Number of points in a row.

 ROW                   (LBROW), header word 18. Number of rows.

 CODE                  (LBCODE), header word 16. Grid code.

The files were generated using the Met Office pp-file utility called "ppfp", as follows:

{{{
 $ summary=${ppfile}-summary.txt
 $ ppfp -start -end -proc -stash -exp -lrec -lblev -lev -hlev $ppfile | grep -v ppfp | grep -v TIME | sed '/^$/d' > $summary

 $ details=${ppfile}-details.txt
 $ ppfp -start -end -proc -stash -exp -lrec -lblev -lev -hlev -lat -lon -npt -row -code $ppfile | grep -v ppfp | grep -v TIME | sed '/^$/d' > $details
}}}