Comparing Positioning Performance of LEO Mega-Constellations and GNSS in Urban Canyons

The use of Low Earth Orbit (LEO) mega-constellations for Positioning, Navigation, and Timing (PNT) services has attracted a great deal of interest, as they could complement the Global Navigation Satellite System (GNSS) in specific conditions/environments. Despite the fact that it is recognized that the use of mega-constellations for positioning services could provide better performance in urban canyons, no work has provided an analysis of such performance improvement. This paper provides a statistical analysis of the performance in terms of availability and Geometric Dilution of Precision (GDOP) of the positioning service of some current mega-constellations in deep urban canyon environments and compares the performance with the one achieved by GNSS systems. A new geometric model for typical urban canyons is developed. The developed model has been used for the analysis of the availability and GDOP of the positioning service in two representative urban canyon areas, namely the city of London and the Manhattan district of New York City. The geometric parameters used in the simulations are derived by statistically processing publicly available data on the height and length of the buildings and the width of the streets in the considered urban areas.