GNSS quality of service in urban environment

Abstract

In the past years, GNSS applications directed to pedestrian and automotive users in urban environment represent an important voice of the GNSS market trend. However, the received signals are strongly influenced by the urban-induced conditions, described in the previous chapter, that significantly affect the tracking loops operation up to loss of position availability. This chapter will address different advanced signal processing or GNSS/sensor integration approaches, in order to assure the navigation quality of service, especially in terms of accuracy and availability. First, an integrated GNSS/video sensor capable of excluding the erroneous measurements will be presented. Afterward, a vector tracking mechanism that performs joint channel tracking and navigation solution will be proposed and its robustness in urban condition is later assessed in details. Also the most precise GNSS measurements-the carrier phase observations-will be considered in terms of their use in urban environments, together with their strengths and weaknesses in terms of the measure of trust in the estimated user position.