OpenSourceGPS Documentation in the form of pdf files is being prepared.

There are many holes in the presentation and it still needs a great deal of work and any suggestions are very welcome.

 

Table of Contents   

Forward

Chapter 1    Introduction

 

            1.1            The RF Signal

                        1.1.1            Bi-Phase Modulation

                        1.1.2            CDMA

                        1.1.3            Data Modulation

            1.2            Satellite Orbits

            1.3            Coordinate Systems

            1.4            Time Systems

            1.5            Navigation Data

            1.6            The Future of Open Source GPS

 

Chapter 2       Getting Started

            2.1            Running OpenSource GPS

            2.2            Compiling OpenSource GPS

            2.3            OpenSource GPS Files

                        2.3.1    Input files

                        2.3.2    Output files

                        2.3.3     Input/Output files

                        2.3.4    Source code

            2.4            Diagnostic Programs

                        2.4.1            Regtest

                        2.4.2            Signmag

                        2.4.3            Debug_processor

            2.5            FAQs!, Issues!, Problems!

 

Chapter 3         Receiver Hardware

            3.1            GPS Antenna

            3.2            Amplification/Filtering

            3.3            DownConversion

            3.4            Analog to Digital Conversion

            3.5            Digital Processor

                        3.5.1            Control Registers

                        3.5.2            Status Registers

                        3.5.3            Accumulate Registers

                        3.5.4            Miscellaneous Registers

                        3.5.5            Hardware Options

 

Chapter 4        Receiver Software

            4.1            Program Structure

                        4.1.1            Constants

                        4.1.2            Globals

 

            4.2            Data Structures

4.2.1                  Channel Data Structures                                

4.2.2                  Satellite Data Structures                                                        

                        4.2.3    Receiver Data Structures

 

            4.3            Receiver Control Algorithms

 

                        4.3.1            Introduction

                        4.3.2            Main

                                    4.3.2.1 Display

                                    4.3.2.2 Channel Allocation

                                                4.3.2.2.1  Cold Allocation

                                                4.3.2.2.2  Warm/Hot Allocation

 

            4.4            GPS Interrupt Service Routine ( GPS ISR )

 

                        4.4.1            ISR Main

                        4.4.2            Search State

            4.4.3            Confirmation State

                        4.4.4            Pull-in State

                                    4.4.4.1 Code

                                    4.4.4.2 Carrier

                                    4.4.4.3 Bit synchronization

                                    4.4.4.4 Pull-in Listing

                        4.4.5            Tracking State

                                    4.4.5.1 Code

                                    4.4.5.2  Carrier

                                    4.4.5.3 Message Synchronization

                                    4.4.5.4 Ch_Track listing

                        4.4.6            Miscellaneous Functions

                                    4.4.6.1            Self test

                                    4.4.6.2 RSS

                                    4.4.6.3 fix Sqrt

                                    4.4.6.4 fix atan2

 

            4.7            Position/Velocity/Time Computations

 

                        4.7.1            Satellite Location

                                    4.7.1.1   Almanac

                                    4.7.1.2   Ephemeris

                        4.7.2            Range corrections

                                    4.7.2.1   Troposphere

                                    4.7.2.2   Ionosphere

                                    4.7.2.2   Satellite clock

                        4.7.3            Other effects

                                    4.7.3.1   Sagnac effect

                                    4.7.3.2   Relativistic effects

                        4.7.4            Computing Pseudorange

                        4.7.5            Computing Delta-Pseudorange

                        4.7.6            Computing Position

                        4.7.7            Computing Velocity

 

            4.8            NMEA Serial Output

 

            4.9            Miscellaneous Algorithms

 

                        4.9.1             ECEF and Latitude/Longitude/Height Conversions

                        4.9.2            Dilution of Precision (DOP)

                        4.9.3            Self Test

                        4.9.4            Navigation Message Decoding

                        4.9.5            Interrupt Install/Remove

                        4.9.6            GP2021 Register Commands

           

Chapter 5      Navigation Performance

 

            5.1            Error Analysis

 

                        5.1.1            Ranging Error

                        5.1.2            Range Rate Error

                        5.1.1            Dilution of Precision

                        5.1.2            Covariance Analysis

 

            5.2            Measured Performance

 

Chapter 6         Appendices

            6.1            ICD-GPS-200 Excerpts

            6.2            GP2015 Specifications

            6.3            GP2021 Specifications

            6.4            Setting the Time Zone Variable

References

 

Clifford Kelley
Copyright 2004  All rights reserved.
Revised: September 25, 2004 .