Microwave photon distributed radar imaging system and method

Abstract

The invention discloses a distributed radar imaging system. The system comprises: a central station which is used for modulating the low-frequency narrow-band linear frequency modulation electric signal into n paths of optical carriers with different wavelengths, transmitting the echo optical signals to a transmitting station and (n-1) receiving stations through optical fibers with different timedelays, performing beam combination and parallel dechirping processing on the echo optical signals from the receiving stations, and performing analog-to-digital conversion, transmission phase delay compensation, frequency domain segmentation and three-dimensional imaging processing on the beam-combined dechirping signals; a transmitting station which converts the radio-over-fiber signals from thecentral station into high-frequency broadband linear frequency modulation electric signals to be transmitted; and the receiving stations which receive the target echo signal, modulate the radio-over-fiber signal from the central station, and transmit the radio-over-fiber signal back to the central station through an optical fiber. The invention further discloses a microwave photon distributed radar imaging method. Photon frequency multiplication, optical fiber radio frequency transmission and photon parallel dechirping processing technologies are applied to the distributed radar, three-dimensional imaging under a one-transmitting-multiple-receiving architecture is realized, the system complexity is reduced, and the system distribution capability and imaging performance are improved.

Description

technical field [0001] The invention relates to the field of radar imaging, in particular to a microwave photon distributed radar imaging system and method. Background technique [0002] Microwave radar has all-day, all-weather, and high-resolution remote sensing imaging capabilities, and plays an indispensable role in land surveying and mapping, resource exploration, environmental disaster monitoring, and regional reconnaissance. With the development of science and technology and the advancement of applications, modern radars are developing in the direction of high resolution, multi-function, miniaturization, and reconfigurability. However, limited by the "electronic bottleneck", it is difficult for electronic technology to realize the generation, control and processing of broadband signals, which poses a huge challenge for traditional radars to achieve multi-band broadband reconfigurability. In recent years, photonic technology has become a "key technology that illuminate...

AI Technical Summary

Problems solved by technology

The problems with this method are: (1) It is difficult to distinguish multiple main scatter points located in the same range-Doppler unit, and there is no geometric resolution in the third dimension; (2) The measurement accuracy of the third dimension increases with the increase of the baseline , but the quality of phase interference also decreases, and there is a contradiction between the two

However, the increased number of transmitters and receivers will exponentially increase system cost and complexity

In addition, the increase of the baseline also brings new challenges to signal coherent processing. In the existing multi-base electronic radar, after the receiver receives the echo signal of the target, it needs to be pre-processed locally, and then sent back to the central site for further processing. Data fusion, so it is difficult to avoid the loss of some information

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