Global Positioning System: Signals, Measurements, and Performance by Pratap MisraThe second edition of this widely praised book offers a comprehensive introduction to GPS: the system, signals, receivers, measurements, and algorithms for estimation of position, velocity, and time. It is intended as a textbook for a senior- or graduate-level engineering course and a self-study guide for practicing engineers.
The book is divided into four parts. Part I introduces the basic framework for a global navigation satellite system, including coordinate frames, time references, and satellite orbits, and provides an overview of GPS, GLONASS, and Galileo. Part II describes the fruits of GPS: estimation of position, velocity, and time. Part III discusses the ingenious structure of the GPS signals. Part IV introduces the signal processing steps required to extract the necessary measurements from these signals, and explores the challenges posed by signal blockage and RFI.
1.9 - Pseudo ranging
Global Positioning System: Signals, Measurements, and Performance (Revised Second Edition)
A receiver does not need to acquire independently the signals in both bands coming from a same satellite, since their carrier Doppler and code delay are closely related. Therefore, the question of which one to acquire first rises naturally. Although the common thought would tell the L1 band signals which are narrowband, an accurate comparison has never been done, and the decision is not as easy as it seems. The results show that overall the L5 band signals are more complex to acquire, but it depends strongly on the conditions. Moreover, precise assistance providing accurate Doppler could significantly reduce the L5 complexity below the L1 complexity. The first stage of a Global Navigation Satellite System GNSS receiver is the acquisition, whose aim is to detect the signal and roughly estimate the code delay and the carrier frequency [ 1 ]. Nowadays, Fast Fourier Transforms FFT are omnipresent in acquisition architectures to accelerate the acquisition, and the amount of memory needed is a major factor in a design [ 2 ].
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As GPS technology becomes more commonplace on the commercial market, many designers are working to improve characteristics such as lower power consumption, the tracking of weak satellites, faster acquisition times, and more accurate position fixes. In this application note, learn how to make a variety of GPS receiver measurements including sensitivity, noise figure, position accuracy, time to first fix TTFF , and position deviation. The goal of this document is to provide engineers with a thorough understanding of GPS measurement techniques. For engineers who are new to GPS receiver measurements, this paper offers a comprehensive overview of common measurements. Engineers who are already experienced at performing GPS measurements can use this document as a resource to introduce new instrumentation technology. This application note is structured according to the following sections:.