Doppler modulation frequency estimation method based on field programmable gate array (FPGA)

Abstract

The invention discloses a Doppler modulation frequency estimation method based on a field programmable gate array (FPGA), and mainly solves the problems of complicated structure, high power consumption and low efficiency of a Doppler frequency modulation system. The method comprises the following steps of: calculating a power sum of distance units which input bidimensional data, and storing the input bidimensional data into an external memory; performing bubble sequencing on the power sum of the distance units, and establishing an index vector; reading the data of the distance units from the external memory according to the index vector; classifying the data of the distance units into front aperture data and rear aperture data, performing fast fourier transform (FFT) and molding operation on the data, and thus obtaining two paths of spectrum data; synchronizing the two paths of spectrum data, performing fast relevant processing, and thus obtaining a relevant vector R(i); accumulating and summing the R(i) to obtain a total relevant vector R; and calculating a Doppler modulation frequency according to the R. By the method, the structure complexity of a system is reduced, the power consumption of the system is reduced, and the processing speed of Doppler modulation frequency estimation is increased; and the method can be used for real-time imaging processing of a synthetic aperture radar.

Description

technical field [0001] The invention belongs to the technical field of digital signal processing, and in particular relates to a method for estimating Doppler modulation frequency by using a field programmable logic gate array FPGA, which can be applied to synthetic aperture radar real-time imaging processing. Background technique [0002] As an active microwave sensor, synthetic aperture radar (SAR) is not limited by light and climate conditions to achieve all-day and all-weather earth observation, obtain high-resolution ground scene information, and obtain subsurface information through the surface and vegetation. And can detect hidden targets. These characteristics make it have unique advantages in military fields, such as battlefield terrain detection and early warning, and civilian fields, such as resource investigation, environmental monitoring, hydrological observation and other applications. [0003] Doppler modulation rate is the main factor affecting the azimuth f...

AI Technical Summary

Problems solved by technology

In the traditional real-time imaging processing, the estimation of Doppler modulation frequency mostly adopts the digital signal processor DSP as the core processing chip, and in order to meet the requirement of increasing the speed, in most cases, multiple DSPs are used for calculation at the same time, but The disadvantage of this method is that the system structure is complicated, the power consumption is large, and the efficiency is low, and because the DSP processing itself is a kind of serial processing, the implementation of DSP is relatively time-consuming, and for some occasions with more stringent real-time requirements, Often difficult to meet real-time processing requirements

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