GNSS constellations monitoring using a phased array antenna system

Global Navigation Satellite Systems (GNSS) have become indispensable for numerous applications,ranging from the synchronization of critical infrastructure to precise navigation applications. It isimperative to establish reliable monitoring systems that ensure the dependability and security ofsatellite constellations, given society's increasing reliance on GNSS for accurate positioning, timing, andnavigation. This study introduces a cutting-edge GNSS monitoring antenna system which deliver high-performance results.The antenna system is composed of multiple blocks: a reconfigurable 64 elements dual-frequency(L1/L5) array antenna, filtering stage, amplification and phase shifting stages, signal combiners and aGNSS receiver stage. The proposed antenna is modular, i.e., each component can be controlledindependently from the others, allowing easy maintenance and more interestingly, re-configurableantenna specifications. To receive multiple GNSS signals at the same time a custom receiver block hasbeen designed to have 8 RF signal input with each beam created by the antenna connected to a GNSSreceiver which is multi-constellations and dual frequency. All the signals are then logged or observedlive.A Raspberry Pi is connected to the receivers to actively control the beams using the publicly availablesatellites ephemerides (using two-line element files) and changing the phase on each antenna element.The antenna array is built with 8 panels of 8 elements (2x4 distributions) which can be arranged inmultiple shapes. Accordingly, the operator can assemble the panels to have a unique and a very highgain beam or he can choose to create up to 8 sub-arrays, i.e. 8 different beams. These sub-arrays canthen be oriented toward different directions to have a full-sky coverage. The shape can also beoptimized to achieve a high level of interference and multipath mitigation for GNSS applications. Byexploiting the analogue beamforming technique, the beams are steerable which enable the tracking ofGNSS satellites.