Multiple Aircraft Tracking System for Coordinated Research Missions

Abstract

The Multiple Aircraft Position System (MAPS) was developed by the Convective Storms Division of the National Center for Atmospheric Research, in response to the need for aircraft position in the coordination of large field projects involving several research aircraft. Radio interferometer techniques are used to provide rapid, accurate determination of positions for up to 10 aircraft furnished with special airborne radio beacons. Three remote interferometer array sites receive the signals from the airborne beacons, each transmitting at a unique frequency. Each remote site is tuned to one beacon frequency at a time according to a programable polling sequence; several phase difference measurements are made from the received signal. These data then are telemetered to a central control station where they are transferred to a computer that calculates the direction cosines from each remote site to the airborne beacon, and thus determines the position of the beacon. The aircraft positions then are immediately available for display. The deployment of MAPS near Miles City, Mont, for the 1981 Cooperative Convective Precipitation Experiment (CCOPE) field program is described.