Based on signal energy received by receiving radar,we built up a distance estimation model,proposed a new algorithm for distance estimation based on structure stochastic jump optimal filter theory,and realized distance estimation of passive radar.

Based on the principle of measuring the distance of the target’s infrared irradiation,a distance estimation model with Markov jump parameters was presented which was aimed at maneuvering point targets.

Aiming at maneuvering point targets flying in the sky,a uniform missile-borne passive system(include infrared passive system and passive radar system) distance estimation model with Markov jump parameters is built by using the spectra radiation illuminance of the targets.

Then the range estimation was performed with the estimated DOA through finite one-dimensional searching.

In this paper, we present theoretical analyses of the target range spectrum and the effects on the range spectral amplitude due to the target movements,based on which we propose a novel high-accuracy instantaneous range estimation algorithm in HF chirp radars.

On the contrast,this paper provided an in-depth analysis of the ranging step in RIPS,and used simulation experiments to research the quantificational impact on the range estimation precision of phase error distribution,channel number,channel interval and searching space,etc.