Coherent Integration for Targets with Constant Cartesian Velocities Based on Accurate Range Model

TL;DR

This paper introduces a novel Radon Fourier transform method for coherent integration of targets with constant Cartesian velocities, improving detection performance by accurately modeling range evolution and eliminating nonlinear signal migrations.

Contribution

The paper presents a new integration method based on an accurate range model that overcomes limitations of previous polynomial models for CCV targets.

Findings

Effective energy integration regardless of target speed

Eliminates high order range and Doppler migration

Enhances speed resolution and detection performance

Abstract

Long-time coherent integration (LTCI) is one of the most important techniques to improve radar detection performance of weak targets. However, for the targets moving with constant Cartesian velocities (CCV), the existing LTCI methods based on polynomial motion models suffer from limited integration time and coverage of target speed due to model mismatch. Here, a novel generalized Radon Fourier transform method for CCV targets is presented, based on the accurate range evolving model, which is a square root of a polynomial with terms up to the second order with target speed as the factor. The accurate model instead of approximate polynomial models used in the proposed method enables effective energy integration on characteristic invariant with feasible computational complexity. The target samplings are collected and the phase fluctuation among pulses is compensated according to the accurate range model. The high order range migration and complex Doppler frequency migration caused by the highly nonlinear signal are eliminated simultaneously. Integration results demonstrate that the proposed method can not only achieve effective coherent integration of CCV targets regardless of target speed and coherent processing interval, but also provide additional observation and resolution in speed domain.