Ch 26. GNSS Receiver Antennas and Antenna Array Signal Processing

Overview:

An antenna is one of the primary components of all GNSS receiver systems. Its performance and characteristics play critical roles in driving the received signal quality as well as relating the receiver’s position solution to a precise point in physical space. A testament to the importance of antennas in the GNSS community is the sheer variety of antennas that are available for different navigation, surveying, and timing applications. For receiver system designers and their users, it is essential to understand how a particular antenna could affect a specific GNSS receiver application. It is also important to be familiar with antennas that offer special capabilities. This applies to both simple, single‐element antennas as well as more advanced antenna arrays, which have found increasing utility in the state‐of‐the‐art GNSS receiver systems.

This chapter provides an understanding of the key features of modern GNSS receiver antennas and antenna arrays. The first half of the chapter is devoted to single‐element antennas. The first section begins with a review of important antenna concepts and terminology. Next, the reader is shown how an antenna can be modeled as a simple direction‐dependent filter, which provides a convenient and accurate means of understanding how an antenna will affect a GNSS receiver’s pseudorange and phase measurements. This is followed by a survey of different GNSS antenna types used in modern practice, and the motivations behind their use in different applications will be discussed. The second half of this chapter is devoted to multi‐element antenna arrays. A review of important antenna array design parameters is provided along with a discussion of how antenna arrays are used in GNSS receiver systems. The final sections address a variety of array signal processing techniques used to provide enhanced capabilities to GNSS receivers.