Analysis of the Results of Astroclimate Research at the Kara-Dag Radioastronomical Station in Crimea and the Possibilities for Reducing the Influence of the Atmosphere on Millimeter-Band Radioastronomical Observations

The results of astroclimate research at the Kara-Dag radioastronomical station (Crimea) from July 22 to September 21, 2017, are presented. The algorithms for processing the data obtained by the atmospheric profile method are analyzed. The broad bands of the MIAP-2 receivers are shown to lead to a non-cosecant dependence of the antenna temperatures on viewing angle. The absorption calculation from three zenith angles by the least-squares method and a reference region with a brightness temperature close to the air temperature is optimal. The patterns of change in atmospheric transparency parameters and their connection with the climatic peculiarities of the observing site are considered. The existing atmospheric circulation is shown to create favorable conditions for nighttime astronomical observations in the millimeter wavelength range on the territory of the Kara-Dag station. Alternative and cheaper approaches to reducing the influence of atmospheric moisture on the measurements in this range than the existing trends are proposed. The first approach consists in choosing a location in a zone with a suitable wind rose and a relief leading to the replacement of moist warm air by dry cold one, for example, in the zones of such local winds as a bora. The second approach suggests the introduction of atmospheric parameter measurements by radiometric methods and allowance for their influence in a real time scale. Since the results obtained are based on limited statistics, they are preliminary ones and stimulate further systematic measurements at Kara-Dag.