Satellite selection in the context of an operational GBAS

Abstract

When incorporating multiple constellations into future ground based augmentation systems (GBAS), a problem with limited VDB (VHF data broadcast) capacity might arise. Furthermore, the number of airborne receiver tracking channels could be insufficient to use all visible satellites. One way to cope with these issues is to perform a satellite selection to limit the number of used satellites with minor impact on performance. This paper investigates different factors that constrain the approach of simply selecting "the best set in every epoch" and shows how to overcome some limitations. These constraints include limitations in satellite visibility, loss of satellites during approach (i.e. in curves), and convergence times in the airborne processing until satellites are usable. Various protection level simulations are performed to show the influence of the named factors on the nominal performance. Taking into account all these contextual influences, results show satellite selection is still applicable in GBAS ground stations. NAVIGATION. 2019;66:227-238. wileyonlinelibrary.com/journal/navi

A satellite selection algorithm based on adaptive simulated annealing particle swarm optimization for the BeiDou Navigation Satellite System/Global Positioning System receiver

“…In general, the PSO algorithm is used to solve optimization problems in nonlinear complex systems and has been successfully applied in many fields, such as production scheduling, system control, and image processing, such as: Guo et al 27 proposed a distributed PSO approach, which can optimize the hyperparameters to find high-performing Convolution neural network (CNN); M Wang et al 28 proposed to apply the PSO algorithm to the application of power cables; ES Wang et al 29 proposed to apply the PSO algorithm to the autonomous integrity monitoring algorithm of navigation receivers. By analyzing the existing research, it can be known that the PSO algorithm can greatly improve the real-time performance, but it is difficult to meet the accuracy requirements in places with higher accuracy requirements.…”

Research on Satellite Selection Strategy for Receiver Autonomous Integrity Monitoring Applications

“…Researches have also been carried out in recent years to improve the integrity performance of chosen subset in augmentation systems such as the satellite-based augmentation system (SBAS) [25], advanced RAIM (ARAIM) [23,31], and ground-based augmentation systems (GBAS) [32,33]. A "measurement downdate" method is carried out for SBAS applications in [25], which once determines a set of impact values termed "measurement" for the all-in-view solution and retains the several satellites with the largest impact values to construct a superior subset for both vertical and horizontal protection levels.…”

“…It uses a similar measurement ranking selection strategy for the initial subset then iteratively optimizes them in a "greedy exchange" way thus improves the selection quality but accompanies with an increased computational cost. Later, this heuristic satellite selection method is applied to the GBAS applications and augmented against timescale constraints, including limitations in satellite visibility, loss of satellites during approach, and convergence times in the airborne processing until satellites are usable [33]. Unfortunately, all the methods above require integrity aid information from the ground station or geostationary satellite, and thus are not suitable for the traditional RAIM process [25,34,35].…”