Multichannel frequency modulated continuous wave SAR (synthetic aperture radar) imaging method

Abstract

The invention provides a multichannel frequency modulated continuous wave SAR (synthetic aperture radar) imaging method. The technical scheme includes that the multichannel frequency modulated continuous wave SAR imaging method includes transmitting frequency modulated continuous wave signals by a channel and receiving the same by M channels simultaneously, and acquiring M channels of azimuths of undersampled two-dimensional frequency modulated continuous wave SAR echo signals; subjecting the acquired M channels of signals to two-dimensional Fourier transform, performing Doppler defuzzification in a two-dimensional frequency domain and acquiring equivalent single-channel signals eliminating azimuth aliasing; focusing the equivalent single-channel signals in the two-dimension frequency domain to obtain two-dimensional high-resolution frequency modulated continuous wave SAR images. Compared with existing single-channel frequency modulated continuous wave SAR imaging method, the multichannel frequency modulated continuous wave SAR imaging method can be operated in the mode with longer operation distance, wider measuring band width and higher imaging resolution under the condition of same transmission power, and application of the frequency modulated continuous wave SAR is broadened.

Description

technical field [0001] The invention belongs to the technical field of radar, and in particular, the invention relates to a multi-channel frequency modulated continuous wave SAR (Synthetic-aperture radar, synthetic aperture radar) imaging method. Background technique [0002] Synthetic Aperture Radar is an active microwave remote sensing device, which can realize earth observation all day, all weather, and obtain subsurface information through the surface and vegetation. It plays an important role in many fields of national economy and military applications. . [0003] FM CW SAR is a high-resolution radar imaging device with small size, light weight, low cost and strong anti-jamming capability. It is currently the most important type of miniaturized SAR. on demanding flight platforms. At present, the weight of the FM CW SAR developed in the United States is less than 2.5kg, the maximum power consumption is only 35W, the longest operating distance is less than 4km, and the ...

AI Technical Summary

Problems solved by technology

Increasing the transmission power can increase the radar's operating range and the width of the surveying band, but this greatly increases the requirements for the device and increases the complexity of the system

What's more serious is that in the high power state, the unique transceiver isolation problem of FM continuous wave radar will be very prominent, which is the most fundamental factor limiting the working distance of FM continuous wave radar

Increasing the antenna aperture can increase the amplification gain of the antenna, but this will limit the azimuth resolution on the one hand, and limit the imaging swath width on the other hand

Reducing the PRF can increase the accumulation time in the range direction, thereby improving the processing gain in the range direction, but this will easily lead to spectral aliasing in the case of high azimuth resolution

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