Implement method and system of microwave photon radar for small target detection or real-time tracking imaging

Abstract

The invention provides an implement method and system of microwave photon radar for small target detection or real-time tracking imaging. The implement system mainly comprises a transmitter, a receiver and a control and data processing center. According to the transmitter, a continuous single frequency laser is used as light sources of an entire radar system, and then a required high-frequency wide-band radar radio-frequency signal is generated by using an optoelectronic combined high frequency doubling method. The receiver uses an optical signal from the transmitter as an optical local oscillator to perform optical mixing and receiving of radar echo. According to the control and data processing center, the workflow of the entire radar system is controlled and the extraction of target information in an echo signal is realized. The implement method and system utilize the advantages of optical high frequency doubling to generate an ultra-wideband radar signal, the resolution ratio of centimeter or even sub-centimeter magnitude is realized, and identifying of a target feature by imaging a target is sufficient; a multi-branch photoelectric conversion front-end framework is proposed, the potential of an electronic power amplifier is fully exerted, and the requirements of the low-frequency narrow-band remote detection function and the high-frequency wideband short-range imaging function can be met only by branch switching; and the advantages of electric low-frequency high-quality signals and optical wideband compatibility can be simultaneously exerted, and long-distance detectionand close-range real-time imaging supervision of small flying targets such as unmanned aerial vehicles can be realized based on a set of the system.

Description

technical field [0001] The invention relates to the field of microwave photon radar, in particular to a method and system for implementing microwave photon radar for small target detection or real-time tracking and imaging. Background technique [0002] Due to its all-weather and all-weather inherent advantages, radar has always been an effective monitoring tool for flying targets in airspace. The game development between traditional air targets such as fighter jets and cruise missiles and radar is in the ascendant. Emerging UAV technology brings a series of new challenges to national defense airspace security. Security risks. Traditional radars are still unable to achieve effective monitoring in the face of slow and small targets. There are two main reasons: one is that small flying targets such as drones are small in size (meter or even sub-meter level), and traditional radars are limited by bandwidth. It is difficult to monitor its behavior with high-resolution detectio...

AI Technical Summary

Problems solved by technology

[0003] The world's first microwave photonic technology imaging radar was proposed by the Italian research team (F.Scotti, F.Laghezza, D.Onori, and A.Bogoni,"Field trial of a photonics-based dual-band fullycoherent radar system in a marine scenario, "Iet Radar Sonar Nav 11(3), 420-425(2017).), the radar uses a frequency conversion scheme based on a mode-locked laser to generate a dual-band chirp signal, which realizes effective imaging of cargo ships and civil aviation aircraft, but each The bandwidth of each frequency band is only 18MHz, and the resolution of composite broadband imaging is only in the order of meters

In addition, given the challenge of mode-locked lasers with large mode spacing, this method cannot realize large-bandwidth radar systems and high-precision imaging of small targets.

Li Wangzhe's research group from the Institute of Electronics, Chinese Academy of Sciences reported a microwave photonic imaging radar based on dual-source dual-link architecture and polarization demultiplexing technology (R.Li, W.Li, M.Ding, Z.Wen, Y.Li, L.Zhou ,S.Yu,T.Xing,B.Gao,Y.Luan,Y.Zhu,P.Guo,Y.Tian,and X.Liang,"Demonstration of a microwave photonic synthetic aperture radar based on photonic-assisted signal generation and stretch processing, "Opt.Express 25(13), 14334-14340(2017).), based on the 600MHz bandwidth, the imaging of the 800m distant civil aviation airliner is realized, but the 43cm resolution is still difficult to effectively image the UAV target, and The implementation of dual-link architecture and polarization demultiplexing technology makes the system relatively complex

Pan Shilong's research group at Nanjing University of Aeronautics and Astronautics built a microwave photon radar experimental system based on laboratory instruments. In the literature (F. Zhang, Q. Guo, Z. Wang, P. Zhou, G. Zhang, J. Sun, and S.Pan,"Photonics-basedbroadband radar for high-resolution and real-time inverse synthetic apertureimaging,"Opt.Express 25(14), 16274-16281(2017).) demonstrated the detection of drones and other targets tens of meters away Real-time imaging, but its signal generation is based on the quadrupling frequency technology of dual parallel Mach-Zehnder modulators, which requires the control of three bias states of the modulator and the injection of electrical low-frequency signals that are strictly orthogonal in phase, The system is complex and difficult to stabilize, which is not conducive to the observation of large-scale and long-term targets

In the patent application (Application No. 201710796669.X), a chip-based microwave photonic imaging radar architecture is proposed, which uses two-way optical modulation to realize signal generation based on optical quadruple frequency technology. The power adjustment and phase shifting of the optical carrier can realize the cancellation of the optical carrier in the upper and lower branches. This method requires strict phase relationship and power relationship, and it is difficult to realize the full cancellation of the optical carrier, resulting in a higher clutter frequency in the transmitted signal. component, which ultimately makes imaging results with poor dynamics and resolution

[0004] Through the above comparative analysis, microwave photonic radar has no stable and effective large-scale real-time monitoring solution for the effective monitoring of drones at present. Insufficiency of the method

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