A.S. Petrov1, V.P. Makarov2

1,2 Lavochkin Association (Moscow region, Khimki, Russia)

1 aspetr50@mail.ru, 2 makarovVP@laspace.ru

When studying the Earth's surface using synthetic aperture radars (SAR), it becomes necessary to accurately quantify the intensity of the electromagnetic wave reflected from various parts of the land and ocean. The main task of radiometric calibration (RMC) is to determine the specific radar cross section (SRCS) of the surface and the radar cross section (RCS) of individual targets located on it using the image of the terrain formed by the SAR.

To this end, it is necessary to create systems for relative calibration of the SAR image (to identify the relative brightness of pixels in the same view) and absolute calibration (to generally link the brightness of all pixels in the image to the brightness of the reference target/targets). The problem is to provide such a volume of controlled system parameters that, using special algorithmic and software, will allow determining the RCS of targets and the SRCS of the earth's surface with high accuracy.

The article describes the problem of radiometric calibration. A general scheme with sources and a list of components of the RMC error is presented. The relations for calculating the values of the SRCS at the stages of the signal pre- and post-processing are given. New methods of internal radiometric calibration of radar images using the pseudo-noise channel separation method of large phased array antennas are described. The description of the test site and calibration equipment used by the German Aerospace Center, as well as the control system for the products of aircraft and space SAR missions used by the European Space Agency, is given. A starting list of literature is provided, introducing the reader to this subject.

Petrov A.S., Makarov V.P. Radiometric calibration of synthetic aperture radar images. Achievements of modern radioelectronics. 2024. V. 78. № 11. P. 17–27. DOI: https://doi.org/10.18127/j20700784-202411-02 [in Russian]

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