A Model for Data-Pilot Biases in Presence of Satellite and Receiver Imperfections

Abstract

Data and pilot channel of the Global Positioning System (GPS) L5 signal and other modernized signals of the global navigation satellite system (GNSS) are subject to an intra-signal bias. This tracking-mode dependent bias causes problems for the harmonized usage of receiver network data, such as from the International GNSS Service (IGS). While previous studies have focused on exhaustive numeric analysis of the data-pilot bias, this work takes a closer look at the possible causes at satellite and receiver level. Our findings indicate that the data-pilot bias on GPS L5 can be well explained with a small set of parameters that are all related to the payload. These parameters include the digital distortion of data and pilot component, plus a relative shift of the two components. Furthermore, our numerical results indicate that the according inter-signal corrections (ISCs) may need more frequent updates.