Argus mapping observations of DR21. The observations used frequency switching.
There is one 187.5 MHz spectral window with 65536 channels centered at 93173.704 MHz ().
The map is 120 by 120 arcseconds, and each scan is 30 seconds long. There are a total of 24 scans (rows) in the map.
The observer used the vane to calibrate at the start and at the end of the observation.
The mapping scans are 37 to 60, and the vane calibration scans are 35, 36 and 61, 62.