Total Power Observing with the DAS

  For certain applications it might be advantageous to use very coarse spectral resolution. Examples include planetary (and telluric) lines and extragalactic emission. The DAS stores total power levels for each of the sub-bands, so that if one observes with the 920-MHz configuration, 8 spectral channels each 125 MHz wide are effectively available. To invoke this mode the software setup changes are minimal; this mode simply stores the total power readings after each phase and they are saved at the end of the GSD file. Aside from the additional numbers, the mode is transparent to the user. To turn on this mode of observing the operator will issue the following commands:

ICL> load mt_prcdir:dastp (You have to do this only once)
ICL> dastp_on

To turn it off, the following command is required:

ICL> dastp_off

Please remember to turn off the total power mode at the end of the observations which need it. If it is accidentally left turned on, it will not harm your data but it will produce larger data files with unnecessary extra data, thus eating up more of our precious disk space.