SDR- and UAV-Based Wireless Avionics Intra-Communication Testbed

In the never ending search for better fuel efficiency and increased safety, the aviation technical community is exploring wireless avionics as a solution. In this work, a Wireless Avionics Intra Communication (WAIC) testbed is designed by using an Unmanned Aerial Vehicle (UAV) equipped with a Software-Defined Radio (SDR). One of the key WAIC performance metrics, the aggregate power flux density (PSD) is measured at a defined radius from the aircraft in a hemispherical pattern of positions where the frequency spectrum is registered at six rings spaced by 15° around the grounded airplane, as required by Radio Technical Commission for Aeronautics (RTCA) minimum aviation system performance standards (MASPS) for WAIC. The described measurement task is performed autonomously by using a hexacopter with a wingspan of 55 cm to fly a predefined programmed hemispherical path by using real-time kinematic GPS. A gimbal-controlled radar altimeter antenna is mounted to the UAV and connected to an on-board SDR and computer. GNU radio is used on an Nvidia Jetson TX2 along with a HackRF One SDR to record the power spectrum in the 4.2-4.4 GHz range. Average power readings are transmitted wirelessly to the operator to confirm system operation during flight, while the raw spectrum data is stored on-board for analysis after the UAV lands. Each measurement set is stored along with the GPS location of the UAV at the moment of testing, as it performs the hemispherical planned path. Another SDR is used on the ground to mimic the operation of a radio altimeter or other WAIC devices during the testing process.