An AGC adjustment method of FPGA-based space-borne interferometric imaging altimeter

Abstract

The invention discloses an AGC adjustment method for satellite-borne interference imaging height gauge based on FPGA. The method comprises the steps of 1, using a current pulse attenuation code to perform ADC sampling, and collecting an echo signal of transmitted pulse; 2, computing a current echo amplitude mean value according to the collected echo signal; and 3, forming multiple sections by division according to an injected expected echo amplitude upper limit value and an injected expected echo amplitude lower limit value, and judging whether the current echo amplitude mean value is positioned in the specified section; if the section where the current echo amplitude mean value is located is the specified section, using the current pulse attenuation code as an attenuation code value applied to echo signal sampling of the next transmitted pulse; and if the section where the current echo amplitude mean value is located is not the specified section, generating the next pulse attenuationcode to serve as the attenuation code value used when the echo signal is sampled at the next time according to a judgment result and the current pulse attenuation code. According to the method, the echo signal amplitude mean value can be quickly adjusted to the proper section.

Description

technical field [0001] The invention relates to the field of space-borne wide swath interferometric imaging altimeter, in particular to an AGC adjustment method of an FPGA-based space-borne interferometric imaging altimeter. Background technique [0002] AGC (Automatic Gain Control, automatic gain control) can improve the dynamic range of the receiver. When the amplitude of the echo signal input to the receiver changes drastically, the receiver can keep the amplitude of the output signal relatively stable through the AGC, so as to be collected and further processed by a subsequent ADC (Analog-to-Digital Converter, analog-to-digital converter). Therefore, AGC is widely used in fields related to analog signal reception such as radar and communication. [0003] In the prior art, reference [1] (Chinese patent CN106505959A, a digital microwave system high-gain radio frequency channel AGC control loop,) provides a control gain adjustment device by judging the size between the int...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the problem that the AGC adjustment method in the field of communication in the prior art is not applicable to the spaceborne interferometric imaging altimeter, and to provide an AGC method that can set the expected echo signal amplitude of the target according to different observation scenarios and quickly adjust

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