Calculate RMS and NEFD via two methods to compare with ITC
The average NEP and its standard deviation are determined for the observation corresponding to the current file. The FCF is used to convert that to an NEFD and thus an RMS using the length of the observation. The RMS for the map is derived from its error component, and the NEFD computed from this and the exposure time image. Finally the ITC is used to determine the expected noise and NEFD for the integration (elapsed) time.
The results are written to a log file, log.checkrms.
The input map is trimmed to a circle 90 arcsec in radius unless otherwise specified by the recipe parameter below.
The input files must correspond to single observations, not coadds, because the elapsed time cannot be calculated for coadds. The recipe will print an error if it detects that the input data have been coadded/mosaicked.
The input data are calibrated in mJy/beam if necessary.