R.R. Alimirzoev1, B.B. Nikolenko2, N.P. Kolesnikov3, A.O. Slavyanskiy4

1-4 JSC “Central radio-research institute named after academician A.I. Berg” (Moscow, Russia)

Synthetic aperture radar technology is widely used to obtain images of the Earth's surface using various types of aircraft. The main advantage over optical shooting methods is all-weather and round-the-clock surveillance. The disadvantages of this technology are the relative complexity and high cost of hardware and algorithms.

Currently, numerous specialists from different countries are constantly working to improve both the SAR resolution and the methods of processing radar images for their presentation to the operator. A modern promising and practically important direction is air-based SAR systems with the possibility of simultaneous operation in several bands and with signals with different polarization.

The purpose of the development of embedded processing algorithms was to provide the possibility of obtaining radar data, unlike analogues, in hard real-time mode with the required resolution on board atmospheric and non-atmospheric aircraft.

This goal was achieved during the study due to the fact that the processing of the responses of probing signals with linear frequency modulation from objects is performed in the time domain at a high (up to 100 MHz) speed using FPGAs as part of the hardware unit "system on a chip". The detection of the response signal from the object is performed based on the results of the calculation of the autocorrelation function in the FPGA, where the representation of the probing pulse in the time domain is used as a reference function. The use of FPGAs allows parallelization of computing processes, the ability to work with ultra-high-frequency signals. The developed algorithm is flexibly configured due to the possibility of reconfiguration of the embedded software implementing it both before launch and during operation of the device, which allows the device to be used when probing the Earth's surface from atmospheric and non-atmospheric aircraft at various sensing distances for frequency-modulated and frequency-controlled signals.

In the course of the work, mock-up samples of a radar station with a synthesized X- and L-band aperture were developed, designed for remote sensing and obtaining radar images of the underlying surface directly on board the SAR carrier.

The developed mock-up samples of X- and L-band ATS were tested in full-scale conditions in order to confirm the claimed characteristics and develop software and algorithmic support.

Based on the results of manufacturing and testing of mock-up samples of X- and L-band radars, it was decided to create an onboard multifunctional dual-band radar.

In the future, it is planned to work out the created dual-band airborne radar and its integration into a single on-board power supply network and a single on-board time system of the carrier - an unmanned aerial vehicle, in order to create a multifunctional unmanned aerial surveillance radar complex.

Alimirzoev R.R., Nikolenko B.B., Kolesnikov N.P., Slavyanskiy A.O. Design of a dual-band radar. Radiotekhnika. 2022. V. 86. № 5. P. 64−71. DOI: https://doi.org/10.18127/j00338486-202205-08 (In Russian)

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