Understanding the GNSS signal model

Abstract

The aim of this chapter is to guide anyone who is new to the Global Navigation Satellite System (GNSS) field through the basics of navigation signal modelling. The chapter explains the relation between the mathematical model and physical reality. It reveals some basic facts which are usually hidden in an advanced literature on signal processing in GNSS. In detail, it focuses on the noise modelling and it provides a recipe to properly set the noise level in a computer simulation to authentically reflect the real situation. It also provides an explanation of the Doppler effect and it discusses its overall impact on the received navigation signal.