Calibration system of BMSTU radio-telescope RT-7.5

For calibration of 2.2 and 3.3 mm radiometers installed in secondary (Cassegrain) focus of the radiotelescope RT-7.5 the black-body calibrator was designed. The calibrator is destined for successive installation of two levels of calibrating noise signal in two bands simultaneously. Two levels are necessary for determination of origin and brightness temperature scaling factor. Due to the big width of signal beams and necessity of providing equal calibrating signal levels at the two wavelengths, black-body radiators were chosen. Temperatures of the black-body radiators are stabilized at +50/spl deg/C and +70/spl deg/C.