The received power of a point source at a specified x,y offset position.

Definition:

This is a built-in group datatype, defined as:

  group PointSourceSample {
    Double xoff,             # The cross-elevation tracking offset.
    Double yoff,             # The elevation tracking offset.
    Double flux,             # The average flux at the above position.
    Double sdev              # The uncertainty in the above flux.
  }

The xoff and yoff members should contain the sky x,y tracking offsets where the flux measurement was made, and the flux and sdev members should be assigned the corresponding return values of the requested_flux() function at that offset position.

Lists of this datatype are used to pass offset flux measurements to the fit_point_source() function.