Experimental UAV-Aided RSSI Localization of a Ground RF Emitter in 865 MHz and 2.4 GHz Bands

Abstract

Unmanned Aerial Vehicles (UAVs) can be used as low altitude platforms in several applications. In this paper, we propose their use to localize a ground Radio Frequency (RF) emitter by collecting measures of the Received Signal Strength Indicator (RSSI) at different positions. The main contribution of the work consists in the definition of an experimental setup for the simultaneous measures of RSSI and receiver position. The RSSI is measured by an actual transceiver, the Adalm Pluto Software Defined Radio (SDR) development board, programmed with the open-source software GNU Radio. The position is provided by GPS and Inertial Measuring Unit (IMU) sensors on the drone. The measures are acquired in the 865 MHz Short Range Device (SRD) and 2.4 GHz Industrial Scientific Medical (ISM) unlicensed frequency bands. Since the ISM measures can be affected by interference generated by different sources (e.g. Wi-Fi access points and UAV controller), the SRD band is exploited for collecting the RSSI measures with less interference. A maximum likelihood (ML) algorithm is applied to the collected data for estimating the transmitter location. For the considered setup we show that the mean absolute localization error is around 4 m without interference and 5 m with interference. A thresholdbased technique is proposed to improve the accuracy in presence of interference.

Differentiation and Localization of Ground RF Transmitters Through RSSI Measures from a UAV

“…The main new contributions of this paper, which is an extension of our previous work [1], can be summarized as follows:…”

“…• Identification and localization of multiple RF ground transmitters based on the k-means clustering and experimental validation. Compared to [1] new scenarios have been investigated, tested, and experimentally evaluated.…”

“…The emitter setup for the standalone scenario depicted in Fig. 1 was described in detail in [1], which involved transmission of a QPSK-modulated signal at a carrier frequency of f c = 865 MHz without interference and f c = 2.4 GHz with interference. The source of interference in the experimental campaign was a WiFi hotspot and the UAV controller, as shown by Fig.…”

“…The position accuracy of the 2D estimate is around 2.5 m and depends on the number of visible satellites at the time of the trial. This framework is further detailed in [1].…”

“…Unmanned aerial vehicles (UAVs) are expected to have a great impact in the telecommunications sector thanks to their unprecedented mobility. Their main envisaged uses are in search and rescue operations and in providing on-demand deployment of airborne base stations [1] 1 . For such applications, the localization of ground targets from UAVs is often a useful feature and sometimes a necessary requirement [2], [3].…”