RADIO PHYSICS AND RADIO ASTRONOMY

Subject and Purpose. Analysis of ways to increase the accuracy of determining the parameters of the Earth’s atmosphere through the improvement of the ground-based spectral radiometric complex designed for monitoring carbon monoxide (CO) by millimeter radio wave radiation control, which was developed at the Institute of Radio Astronomy of the National Academy of Sciences of Ukraine The purpose is achieved by reducing the measurement errors of the emission amplitude of the observed tracer gas through the operational determination of the absorption of radio waves in the troposphere. By performing a rapid calibration of the troposphere opacity and promptly accounting for changes in radio signal absorption, we increase the accuracy and reliability of measurements of atmospheric CO radio emission intensity. This method is suitable for any systems of this type. By studying the frequency stability of local oscillators of all stages of frequency conversion in the receiving system, the maximum error in measuring stratospheric wind speeds at altitudes from 20 to 80 kilometers was determined.

Methods and Methodology. The improved CO-monitoring setup measures radiometric atmospheric profiles, from which a new data processing method introduced in the paper quickly derives the antenna scattering coefficient. Then, the tropospheric absorption of the radio signal is evaluated immediately during monitoring in near-real time.

Results. The CO-monitoring spectroradiometric complex has been upgraded and improved, enabling the measurement of radiometric atmospheric profiles and providing a prompt, near-real-time determination of the antenna scattering coefficient (previously unavailable). It has been demonstrated that monitoring the antenna scattering coefficient enhances the determination accuracy of the CO emission line amplitude, thereby increasing the reliability and validity of the obtained results. The studies related to the modernization of the monitoring instrument helped us evaluate the accuracy of measuring stratospheric wind speeds.

Conclusion. Practical work and evaluations have proved that measuring tropospheric opacity directly during observations is feasible and significantly increases the accuracy and reliability of the results.

Keywords: millimeter waves, aeronomy, measurement accuracy

Manuscript submitted 06.10.2025

Radio phys. radio astron. 2026, 31(1): 003-010

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