Passive radar time difference and frequency difference coordinated positioning method under errors of motion observation station

Abstract

The invention discloses a passive radar time difference and frequency difference coordinated positioning method under errors of a motion observation station. In view of an external illuminator positioning problem under errors of a position and a speed of the motion observation station, according to acquired TDOA and FDOA measurement, a range and a range rate are introduced as intermediate variables to enable a strong nonlinear equation to be subjected to pseudolinearization, and a target position and speed estimation model is built. According to a measurement error variance, and the observation station position and speed errors, an optimal weight is designed, and estimation is carried out by adopting an iterative weighted least square method. A correlation least square estimation model isbuilt by using the correlation between the intermediate variables and the target position and the speed, and the above target position estimation result is improved. By introducing the intermediate variables, a nonlinear measurement model is reasonably transformed to pseudolinearization, the external illuminator positioning complexity is reduced on the premise of ensuring the estimation performance, and influences on target positioning performance by errors of the observation station are reduced.

Description

technical field [0001] The invention belongs to the field of radar data processing, and in particular relates to a TDOA / FDOA cooperative positioning method for external radiation source radar under the error of a moving observation station. Background technique [0002] The external radiation source radar does not actively transmit signals, and relies on third-party radiation sources (such as TV broadcast signals, TV signals, mobile phone signals, satellite navigation signals, etc.) to detect targets. It has good concealment, low-altitude and ultra-low-altitude target detection, low cost, and Strong interference ability and so on. The external radiation source radar receiving station (observation station) receives the direct wave signal of the transmitting source and the echo signal scattered by the target, and obtains the target angle of arrival (DOA), time difference of arrival (TDOA) and frequency difference of arrival (FDOA) through signal processing test information. ...

AI Technical Summary

Problems solved by technology

Zhao Yongsheng et al. proposed a TDOA / FDOA joint positioning algorithm based on maximum likelihood estimation for single-station external radiation sources. Medium observation stations are often installed on moving platforms such as satellites, aircraft, ships, or ground vehicles. Although the receiver position can be obtained by the navigation system on the positioning platform, it still inevitably contains random errors.

Neglecting the impact of errors can lead to severe degradation of target localization estimation performance, and even false targets

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