GNSS Array Antenna for Mitigating Multipath Errors in Urban Environment

¹ Department of Aerospace Engineering, Osaka Prefecture University, Sakai City, Osaka, Japan
² Department of Aerospace Engineering, Tokyo Metropolitan University, Hino City, Tokyo, Japan
³ Aeronautical Technology Directorate, Japan Aerospace Exploration Agency, Mitaka City, Tokyo, Japan

^* Corresponding author: tsujii@aero.osakafu-u.ac.jp

Abstract

GNSS signal vulnerability has been a major concern especially for safety-of-life applications such as aircraft operations. Therefore, a GNSS array antenna technology was investigated focusing on beamforming to mitigate multipath errors in urban environment including airport surfaces. A commercial three-element GNSS antenna and RF-Front end were used to obtain digital IF data. The recorded In-phase/Quadrature IF data for three antennas were combined with proper weight to form beams towards satellites after so-called hardware biases were calibrated. Test results in multipath-rich environment demonstrated that 50-70% reduction of pseudorange errors due to multipath were possible if the beamforming algorithms were applied.