Asynchronous WAM with Irregular Pulse Repetition

Abstract

Radiolocation systems for aviation based on Multi-Lateration (MLAT) typically use a set of synchronised ground sensors to receive radio signals broadcast by onboard transmitters. In most cases, the sensor synchronisation in Wide Area Multi-Lateration Systems (WAM) is provided by Global Navigation Satellite System (GNSS) receivers. However, in the case of synchronisation failure, there is still a possibility to estimate the coordinates of the tracked aircraft by using the measurements of the time of arrival taken by non-synchronised sensors. The article presents the principle of operation and equations for calculating the coordinates of an aircraft in an asynchronous multi-lateration system, together with the results of a computer simulation allowing comparison of the accuracy of position estimation between the asynchronous and the typical, synchronous MLAT. This paper contains also some comments on the required stability of the clock source for the sensors working in an asynchronous MLAT system.

Voice Multilateration System

“…From the systems mentioned above, the greatest attention is now paid to development and implementation of multilateration (MLAT) or wide area multilateration (WAM) systems which are considered as low-cost alternatives to radar-based aircraft positioning [ 2 , 3 , 4 ]. The MLAT system consists of many measurement sensors deployed in selected places with known coordinates in a given supervision area.…”

Sensor Position Estimation Method for IoT Using Mobile Reference Node

“…All of the described methods need appropriate network infrastructure in the form of base (reference) stations, synchronization mechanisms in the sensor network, and many other necessary elements for proper operation. The localization method proposed in this paper minimizes the network infrastructure and belongs to asynchronous methods [19], [20], [24], [25].…”