makesum
This program generates ascii summary files from Chilbolton-format
data files. Summary files are required by all the programs in this
collection whenever particular rasters need to be extracted from data
files, because they contain the offset in blocks (4092 bytes) of each
raster from the start of the file. They are usually distributed with
the data files, but this program is useful if ever you need to
regenerate them. Summary files generated by makesum differ
from those generated at Chilbolton by the Fortran summary
program in the following minor ways:
- The number of scans reported in the penultimate column is correct;
it allows for the fact that multi-scan rasters are often aborted half
way through.
- The range-gate spacing is correct for cloud data; in some summary
files from Chilbolton the range-gate spacing is reported as 0 metres.
- The date and time are padded by zeros, resulting in for example
`01/01/00' instead of ` 1/ 1/ 0'
It also uses fseek to traverse the file rather than reading
the blocks into memory. This may make it somewhat faster.
The format of a summary file is simple. The first line contains the
name of the corresponding data file, followed by the tape number. The
remaining lines each correspond to a raster and have 20 columns which
are formatted using the C-style format string
"%5u%4u %02u:%02u:%02u %02u/%02u/%02u %c %c %2s %s%5.1f%3d%4d%4d%4d%2d%6.1f%6.1f%6.1f%5.1f%3d%2d\n"
The columns are:
- Block number (1 based) where a block is 4092 bytes
- Raster number
- Time (UTC) in the form HH:MM:SS
- Date in the form DD/MM/YY
- The letter `A': I don't know the significance of this...
- The scan type: can be U (unknown), R (RHI), P (PPI), S (slant
plane), F (fixed), C (calibration) or T (time series)
- Experiment code: there are quite a few different ones, but the
most common are `Cr' (Chilbolton radar?) and `Cl' (Cloud)
- First three letters of the username of the radar operator
- Z calibration figure in dB (i.e. add this figure to the raw values
to get the calibrated values): note that because calibration wisdom
can often change months after the event, this field is NOT used by any
of the programs to perform calibration, it is rather up to the user to
specify what calibration figure to use
- ZDR calibration figure in dB
- Always zero...
- Byte 30 (0 based) of the raster information record
- Gate spacing (m)
- Always zero...
- Minimum angle of scan (degrees)
- Maximum angle of scan (degrees)
- Initial angle of scan (degrees); this is the elevation for PPIs and the azimuth for RHIs
- Angle increment (degrees)
- Number of scans in the file
- Sensitivity flag
Usage
makesum [options] file1.dat [file2.dat ...]
The options are:
- -echo
- Print the summary information on standard output as well as
writing to a file.
- -Zcal f
- Specify Z calibration as f dB.
- -ZDRcal f
- Specify ZDR calibration as f dB.
- -h
- Print help information (can also get help information if
makesum is run with no options).