This program converts Chilbolton-format radar data to ascii. The processing options are shared with chilplot, chil2nc and loadchil, and are described here. The ascii files are written in the current directory. In the case of scanning data, separate files are written for each scan, and the filenames have the form FFFFrRRRsSS.dat, where FFFF is the file or tape number, RRR is the raster number and SS is the scan number. Cloud data is grouped by day, and the filenames have the form YYYYMMDD_FF.dat, where YYYY is the year, MM is the month, DD is the day and FF is the radar frequency in GHz.
The file format is very straight forward. First there is a header in which each line is prefixed by a `%' symbol, followed by the data, one line per pixel. A value of -999 means no signal. Here is an example of running the program on some scanning datacorona$ chil2a /cdrom/6421new.dat 27 -polar -41.7 -43.7 -43.7 -minLDR -10 -ZDRcal 1.5 -Zcal 5 Writing 6421r027s01.dat corona$ less 6421r027s01.dat %File: 6421 %Raster: 27 %Scan: 1 %Date: 20000609 %Time: 08:23:59 UTC %System: CAMRa %Frequency: 3.075 GHz %Latitude: 51.1445 degrees_north %Longitude: -1.437 degrees_east %Altitude: 90 m %Gates: 300 %Columns: 7 %ScanType: RHI %MissingValue: -999 %Options: -polar -41.7 -43.7 -43.7 -minLDR -10 -ZDRcal 1.5 -Zcal 5 %Variables: time azimuth elevation range Zh Zdr Ldr %Units: decimal_hours_UTC degrees_from_west degrees km dBZ dB dB 8.3999 188.983 20.033 5.250 21.9998 0.9999 -33.4707 8.3999 188.983 20.033 5.550 21.9998 0.8749 -33.7625 8.3999 188.983 20.033 5.850 21.9998 0.7499 -34.8718 8.3999 188.983 20.033 6.150 25.7499 0.7500 -35.4520 8.3999 188.983 20.033 6.450 25.9999 1.0000 -36.2507 8.3999 188.983 20.033 6.750 23.4998 0.9999 -33.5094 8.3999 188.983 20.033 7.050 21.4997 0.4998 -33.4318 8.3999 188.983 20.033 7.350 19.9995 0.6248 -34.8776 8.3999 188.983 20.033 7.650 14.2480 0.4990 -33.0289 ...Similarly for cloud data:
corona$ chil2a /data/0090c94d.dat 10 -averays 10 -correctrange -oscillator -Zcal 25 -minelev 85 Writing 20000330_94.dat corona$ less %File: 0090 %Raster: 10 %Date: 20000330 %Time: 10:07:18 UTC %System: Galileo %Frequency: 94 GHz %Latitude: 51.1445 degrees_north %Longitude: -1.437 degrees_east %Altitude: 90 m %Gates: 242 %Columns: 5 %ScanType: Fixed %MissingValue: -999 %Options: -averays 10 -correctrange -oscillator -Zcal 25 -minelev 85 %Variables: time range Zh v sigma_v %Units: decimal_hours_UTC km dBZ m/s m/s 10.1218 0.030 -38.2273 0.0007 0.0209 10.1218 0.090 -41.7464 -0.0036 0.0195 10.1218 0.150 -47.0917 0.0064 0.0179 10.1218 0.210 -52.5179 0.0697 0.1815 10.1218 0.270 -47.2476 -0.0107 2.2973 10.1218 0.330 -45.0758 -0.0718 0.4053 10.1218 0.390 -41.7746 0.0653 0.7442 10.1218 0.450 -38.1127 -0.1737 0.6733 10.1218 0.510 -34.3515 0.6613 0.4483 10.1218 0.570 -35.5215 0.7335 0.5868 10.1218 0.630 -41.9991 1.1669 0.4880 10.1218 0.690 -999.0000 -999.0000 -999.0000 ...