Pulse arrival time stamp marking method based on secondary zero crossing point detection and judgment

Abstract

The invention provides a pulse arrival timestamp marking method based on secondary zero crossing point detection and judgment. According to the method, a time synchronization-based time difference measurement principle is adopted, each of a main station and various secondary stations sets a high-stability and unified time reference, receives a target response signal, detects, judges and digitalizes the target response signal, searches for a signal crossing point, marks a time stamp and acquires the time of arrival of the target response signal, and the main station and the various secondary stations calculate the time of arrival of the target response signal according to the respective time stamps and then transmit the time of arrival to a data processing center; and the data processing center calculates the time difference of arrival according to the time of arrival, and then the position of a target is estimated. The method has the advantages that the time deviations between the marking positions of the time of arrival and the correct time of arrival (the zero crossing points) can be minimized maximally, the purpose of suppressing time of arrival estimation errors caused by zerocrossing point detection is achieved, and the precision of TOA measurement of the base stations can be significantly improved in the environment which is bad in signal-to-noise ratio.

Description

technical field [0001] The invention belongs to the field of aviation technology, in particular to a pulse arrival time stamp marking method for secondary zero-crossing detection and judgment. Background technique [0002] The multilateration positioning system (MLAT) or passive positioning system is composed of several ground receiving base stations (divided into primary stations and secondary stations) and data processing centers distributed in the monitoring area. It is a passive monitoring system based on target response signals. Each base station respectively measures the arrival time of the target response signal and summarizes it to the data processing center. The center calculates the time difference of arrival (TDOA) of the target transmission signal at the master station and each secondary station, thereby realizing the continuous estimation of the target spatial position and completing the terminal Accurate monitoring of targets such as moving and stationary aircr...

AI Technical Summary

Problems solved by technology

Due to the existence of systematic errors and channel random noise, the position of the zero-crossing point of the traditional matched filter detection output deviates from the real value, resulting in a deviation in the time stamp mark of the pulse arrival time. The time of arrival (TOA) calculated according to the time stamp ) large error, thus affecting the positioning accuracy

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