Arrive time measuring method and system of multipoint position dependent surveillance system

Abstract

The invention provides an arrive time measuring method and system of a multipoint position dependent surveillance system. The method comprises under a system reference clock provided by the multipoint position dependent surveillance system, carrying out A / D sampling and quantification on received target response signals, carrying out difference coupling filtering on digital signals processed through A / D sampling and quantification, carrying out zero crossing detection on signals processed through difference coupling filtering to obtain the arrive time of the target response signals through zero crossing detection within the detection threshold. On the premise that the positioning precision of the multipoint position dependent surveillance system is effectively raised and the cost of hardware is reduced, the precision of estimation of the arrive time can be raised, and the error of time measurement of the system can be reduced.

Description

technical field [0001] The invention relates to the field of air traffic control monitoring systems, in particular to a time-of-arrival measurement method and system suitable for multipoint positioning-related monitoring systems. Background technique [0002] The MLAT surveillance system is one of the new air traffic control surveillance technologies vigorously promoted by the International Civil Aviation Organization after the Automatic Dependent Surveillance Broadcast (ADS-B) system. The multilateration related surveillance system is not only compatible with all the functions of ADS-B, but also capable of real-time and precise positioning of aircraft equipped with ordinary A / C / S mode transponders. The basic principle is to receive target A passive positioning system that measures the time of arrival of the same target response and calculates the time difference of arrival (Time Difference Of Arrival, TDOA) between multiple receiving units, and determines the target positio...

AI Technical Summary

Problems solved by technology

The traditional time-of-arrival measurement method for multilateration-related surveillance systems is the pulse rising edge detection method, which is derived based on simple geometric relationships and is not an optimal estimation method. to a certain time error

In addition, due to noise, crosstalk, reflection and other reasons, the rising edge of the pulse will jitter, and the measurement of the arrival time will also bring corresponding time errors.

Time-of-arrival measurement is the prerequisite for accurate positioning of the multi-point positioning related monitoring system. The measurement error of several nanoseconds will gradually amplify as the system runs step by step, and the resulting time error of the entire system will affect the positioning accuracy of the system. have a great impact

If you want to improve the measurement accuracy of the arrival time, you must provide the system with a highly stable synchronous clock and reduce the time error caused by the system's step-by-step amplification. Although the time accuracy requirements for the arrival time measurement can be met at this time, there are still The disadvantages are increased equipment cost, large time measurement error, and low positioning accuracy.

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