Issues of digital acquisition of output signals in a multi-band microwave radiometric system for remote sensing of the atmosphere
Abstract
The article examines the issues of digital acquisition of output signals in a multi-band microwave radiometric system for remote sensing of the atmosphere. Information is given on the correlation between the sensitivity of the microwave radiometric system for atmospheric sensing and the time for its output signals’ acquisition. The tasks are set for choosing the time value for the digital acquisition of output signals based on the correlation analysis of measurement results in the multi-band microwave radiometric system. The microwave radiometric system ensured reception of radiothermal radiation from the atmospheric ground layer in four bandwidths with band centers of 7.5GHz, 3.2GHz, 1.35GHz and 0.8GHz in vertical and horizontal polarization of the main measuring channel and the secondary channel, generating compensation signal. There are presented features of the procedure preparation for digital acquisition of the sequence of weather parameter values for the atmospheric boundary layer and forming arrays of microwave radiometric measurement results in four bandwidths of varying time of measurement interval. There are given estimations for the optimal time of the output signals’ acquisition in the microwave radiometric system using digital data acquisition in the microwave radiometric system over the following periods: from 01.08.2023 to 21.08.2023 and from 09.12.2023 to 29.12.2023. There is presented correlation analysis of measurement and weather parameter results of the atmospheric boundary layer at different time values of the output signal acquisition and the conditions for their optimization are defined as well. It was shown as a result of the analysis data that time increment for the output signal acquisition in the microwave radiometric system has a significant effect for low-frequency channels, which may be due to their lower sensitivity to varying weather parameters such as temperature and humidity of the ground atmospheric layer. There was also revealed the possibility to increase correlation of the results of microwave radiometric measurements and weather parameters using the signal acquisition digital method where there are significant value variations of weather parameters during the microwave radiometric sensing of the atmosphere