Authors: H.S. Veliyev

Title of the article: Issues on two-stages calibration of passive remote sensing devices

Year: 2022, Issue: 6, Pages: 56-61

Branch of knowledge: 2.4.2. Electrotechnical complexes and systems (engineering)

Index UDK: 622.232.72

DOI: 10.26730/1816-4528-2022-6-56-61

Abstract: Solar photometers, being passive remote sensing devices, are the most common measuring instruments from a set of measuring instruments designed to study various indicators of atmospheric optics. Solar photometers allow you to measure some small gases, aerosols, water vapor, as well as solar radiation indicators. The operation of this device is based on the Booger-Behr law, their calibration is the main task of achieving high accuracy of measurements using solar photometers. Calibration of a solar photometer in the mode of passive remote sensing of the atmosphere or solar indicators consists of two calibration procedures performed sequentially: external calibration and internal calibration. The purpose of external calibration is to find a correspondence between the initial radiation of the Sun, or extra-atmospheric radiation. The task of internal calibration of the solar photometer is to find a correspondence between the input optical signal and the output electrical signal of the photometer. The most important task of any remote sensing measuring instrument is its correct external calibration. For external calibration of solar photometers, the Langley diagramming method is usually used, based on the Booger-Baer law. At the same time, both the Langley diagram method itself and its various analytical versions have a significant drawback, which is that the entire calibration procedure must be carried out for a certain period of time when the optical thickness of the atmospheric aerosol changes significantly. A two-stage method of calibration of passive remote sensing devices is proposed, as an example of which a three-wave solar photometer is considered, in which the effect of atmospheric aerosol is corrected by introducing an intermediate calculation parameter and correction coefficients. As the first stage of calibration, the calibration coefficient is found between the extra-atmospheric solar radiation and the input optical radiation of the Sun. As the second stage of calibration, there is a calibration coefficient between the input and output signals of the photometer. The total calibration coefficient turns out to be equal to the product of the above two partial coefficients.

Key words: passive sensing solar photometer calibration aerosol small gases

Receiving date: 15.09.2022

Approval date: 01.10.2022

Publication date: 27.12.2022

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