Evaluation of Radio Astronomically Important Tropospheric Parameters for Effelsberg from Radiosonde Data

摘要

Tropospheric parameters can be measured by radiosondes (RS), microwave radiometers (MR), and infrared spectral hygrometers (IRSH). A four-frequency microwave radiometer was installed on the prime focus of the Effelsberg telescope. It is undergoing tests and calibration. The estimation of various effects from radiosonde data are considered. The effects considered are the phase pathlength L, the integrated water vapor V, the extinction tau, the brightness temperature T, and the refraction N due to the troposphere. The frequency dependent effects (tau and T) are evaluated for the four radiometer frequencies (21.5, 22.2, 22.9, and 23.6 GHz) and for some of the observational frequencies (correponding to wavelengths of 11 cm, 6 cm, 2.8 cm, and 0.7 cm). The radiosonde data used as the basis of this analysis is described.