The opacity of the sky is usually determined by skydip measurements.
However, the values are not very accurate and for a more reliable opacity estimate,
one has to combine the skydips, taumeter measurements and calibrator fluxes.
The raw data coming from SABOCA just have the detector voltage output as intensity. In order to obtain the intensity in astronomical units, the data have to be multiplied with a conversion factor VtoJ [Jy/mV], as shown in the next table. Unable to select database CalPlan