Ground emitter localization via fusing terrain map and DOA measurements using two miniature UASs

Abstract

This paper presents an emitter localization technique based on the fusion of Direction of Arrival (DOA) measurements obtained from two miniature unmanned aerial systems (UAS) and the terrain map of the interested area. The system's objective is to localize an emitter distributed in an area with 2000m radius in real time and the localization error is less than 100m with 95% confidence. In the system, each UAS is equipped with a three-element smart antenna for scanning the desired frequency band, calculating the received signal's spectrum signature and estimating the emitter's elevation and azimuth DOA. The received signal's DOA, spectrum signature, UAS position, and the time that the signal is received (calculated with respected to the pulse per second (PPS) signal of global positioning system (GPS)) are transmitted to the ground control station. At the ground control station, the DOA coming from the two UAS are aligned using the received signal's spectrum signature and time stamp, and then fused with the UAS position and terrain map to localize the emitter. This paper is focused on the localization scheme including the DOA estimation and emitter localization based on data fusion. The simulation conducted shows that azimuth DOA error (about 1.5°) is much smaller than elevation DOA error (about 5°), and the achieved localization error is less than 100m in most cases when the UAS and the emitter are located in an area with radius of 2000m.