Estimation of errors at the calibration of spectral data at the Irbene RT-32 radio telescope

Abstract

We analyze calibration errors that occur during the single-dish observations at the Irbene RT-32 radio telescope when calibration is done using noise diode. Only frequency switched mode of spectral line observations is considered. The purpose of the article is to find possible values of noise diode temperature Tcal and period of switching oscillator frequency 2tq. For this, we have analyzed the formula for calculating the antenna temperature of the source. It is shown that noise diode temperature affects the standard deviation of source antenna temperature σTs and the error of source antenna temperature δTs caused by instability of system temperature. tq affects the stability of the characteristics of the receiving system. In this article, the dependencies between Tcal, tq, σTs and δTs were found and analyzed. Based on these dependencies, possible values of Tcal and tq are found.