Global Positioning System (GPS) Standard Positioning ...

1 5th Edition April 2020 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Global Positioning System Standard Positioning SERVICE PERFORMANCE Standard Distribution Statement A: Approved for public release; distribution is unlimited April 2020 GPS SPS PS (This page intentionally left blank.) FOREWORD This document defines the levels of performance the Government makes available to users of the Global Positioning System (GPS) Standard Positioning Service (SPS). The GPS SPSP erformance Standard underscores the commitment to cooperate with other Global navigation satellite systems and augmentation System providers to ensure compatibility and interoperability of GPS with emerging systems for peaceful, civilian worldwide use. Please refer any questions or comments, in writing, to:Office of the Department of Defense Chief Information Officer Attn: Assistant for GPS, Positioning and Navigation 6000 Defense Pentagon Washington, DC 20301-6000 Frederick D.

2 Moorefield, Jr. Deputy Chief Information Officer for Command, Control, and Communications signed by : 12:05:55 -04'00'April 2020 GPS SPS PS (This page intentionally left blank.) April 2020 GPS SPS PS 5th Edition Page i TABLE OF CONTENTS List of .. iii List of .. iii List of .. iv Executive .. v SECTION The GPS Standard Positioning Service .. 1 .. 1 Scope .. 2 GPS SPS Definition .. 2 Backward 3 Key Terms and Definitions .. 4 Global Positioning System Overview .. 4 GPS Space Segment (SS) .. 4 GPS Control Segment (CS) .. 7 SECTION SPS SIS Characteristics and Minimum Usage Assumptions .. 9 SPS SIS Interface Specification Requirements .. 9 Overview of SPS SIS Interface Characteristics .. 9 SPS SIS RF Characteristics .. 9 GPS NAV Message Characteristics .. 11 GPS SPS SIS Component Combinations.

3 14 Overview of SPS SIS Performance Characteristics .. 15 SPS SIS Availability .. 15 SPS SIS Health .. 16 SPS SIS Accuracy .. 24 SPS SIS Integrity .. 25 SPS SIS Continuity .. 29 SPS SIS UTC(USNO) Accuracy .. 29 Usage Assumptions for SPS Performance Standards .. 30 SPS User .. 30 SPS SIS Configuration .. 30 Single-/Dual-/Triple-Frequency Operation .. 30 SPS SIS Health .. 30 Excluded Errors .. 32 Dummy Satellites .. 33 SECTION SPS SIS Performance Standards .. 35 Overview .. 35 SPS SIS Performance Standards Organization .. 36 CM-Code, CL-Code, I5-Code, and Q5-Code SIS Performance Standards .. 36 24-Slot Constellation Definitions .. 37 SPS SIS Coverage .. 41 Per Satellite Coverage .. 41 April 2020 GPS SPS PS 5th Edition Page ii Baseline/Expandable 24-Slot Constellation Coverage .. 42 SPS SIS Accuracy .. 43 SPS SIS URE Accuracy Standards.

4 44 SPS SIS URRE Accuracy Standards .. 45 SPS SIS URAE Accuracy Standards .. 45 SPS SIS UTCOE Accuracy Standards .. 46 SPS SIS Integrity .. 47 SPS SIS Instantaneous URE Integrity Standards .. 47 SPS SIS Instantaneous URRE Integrity Standards .. 48 SPS SIS Instantaneous URAE Integrity Standards .. 49 SPS SIS Instantaneous UTCOE Integrity Standards .. 49 Psat and Pconst Standards .. 50 SPS SIS Continuity .. 51 SPS SIS Continuity Standards Unscheduled Failure Interruptions .. 51 SPS SIS Continuity Standards Unscheduled Maintenance Interruptions .. 51 SPS Status and Problem Reporting Standards .. 52 SPS SIS Availability .. 53 SPS SIS Per-Slot Availability Standards .. 53 SPS SIS Constellation Availability Standards .. 54 Operational Satellite Count Standards .. 55 SPS Position/Time Domain Standards .. 56 PDOP Availability Standards .. 57 SPS Position Availability Standards.

5 57 SPS Position/Velocity/Time Accuracy Standards .. 58 SECTION References .. 59 Government Documents .. 60 Non-Government Documents .. 62 April 2020 GPS SPS PS 5th Edition Page iii List of Figures Figure Block II Series Satellite GPS SIS Generation and .. 5 Figure The GPS Control Segment (CS).. 8 Figure LNAV Message Content and Format Overview .. 12 List of Tables Table SPS SIS Backward Compatibility .. 3 Table GPS SIS Taxonomy .. 5 Table GPS SPS SIS Broadcast Configurations .. 6 Table CNAV Message Types/Content vs LNAV Subframes/Content .. 13 Table SPS SIS Component Combinations Covered by this Edition of the SPS PS .. 14 Table SPS SIS Performance Standards vs. SPS SIS Signals .. 37 Table Baseline 24-Slot Constellation Slot Assignments as of the Defined Epoch .. 38 Table Expandable 24-Slot Constellation Slot Assignments as of the Defined Epoch.

6 39 Table Reference Orbit Parameters .. 40 Table SPS SIS Per-Satellite Coverage Standards .. 41 Table SPS SIS Constellation Coverage Standards .. 42 Table SPS SIS URE Accuracy Standards .. 44 Table SPS SIS URRE Accuracy Standards .. 45 Table SPS SIS URAE Accuracy Standards .. 46 Table SPS SIS UTCOE Accuracy Standards .. 46 Table SPS SIS Instantaneous URE Integrity Standards .. 47 Table SPS SIS Instantaneous URRE Integrity Standards .. 48 Table SPS SIS Instantaneous URAE Integrity Standards .. 49 Table SPS SIS Instantaneous UTCOE Integrity Standards .. 49 Table SPS SIS Instantaneous Psat and Pconst Standards .. 50 Table SPS SIS Unscheduled Failure Interruption Continuity Standards .. 51 Table SPS SIS Unscheduled Maintenance Interruption Continuity Standards .. 52 Table SPS Status and Problem Reporting Standards .. 52 Table SPS SIS Per-Slot Availability Standards.

7 53 Table SPS SIS Constellation Availability Standards .. 54 Table Operational Satellite Count Standards .. 55 Table PDOP Availability Standards .. 57 Table SPS Position Availability Standards .. 57 Table SPS Position/Velocity/Time Accuracy Standards .. 58 April 2020 GPS SPS PS 5th Edition Page iv List of Appendices Appendix A: SPS Signal-In-Space (SIS) Background Information Appendix B: SPS Position, Velocity, and Time (PVT) Performance Expectations Appendix C: Key Terms, Definitions, Abbreviations and Acronyms Note: A Table of Contents is contained within each respective Appendix. April 2020 GPS SPS PS 5th Edition Page v Executive Summary The Global Positioning System (GPS) Standard Positioning Service (SPS) consists of space-based Positioning , navigation, and timing (PNT) signals delivered free of direct user fees for peaceful civil, commercial, and scientific uses worldwide.

8 This SPS Performance Standard (SPS PS) specifies the levels of SPS performance in terms of broadcast signal parameters and GPS constellation design. The Government is committed to meeting and exceeding the minimum levels of service specified in this SPS PS. Since GPS initial operational capability (IOC) was first declared in 1993, actual GPS performance has continuously met and exceeded minimum performance levels specified in the SPS PS and users can generally expect improved performance over the minimum levels described here. For example, with current (2018) Signal-in-Space (SIS) accuracy, well-designed GPS receivers have been achieving horizontal accuracy of 3 meters or better and vertical accuracy of 5 meters or better 95% of the time. A number of agencies continually monitor actual GPS SPS performance, including the Federal Aviation Administration (FAA) which publishes quarterly Performance Analysis Reports at its National Satellite Test Bed (NSTB) web site ( ).

9 Interested readers are encouraged to refer to this and other sources for updated GPS performance. The performance specifications in this edition of the SPS PS apply to the L1 ( MHz) Coarse/Acquisition (C/A) signal. Information is also provided regarding characteristics of planned L2C ( MHz) Civil Moderate Code (CM) and Civil Long Code (CL) signals, and the L5 ( MHz) In-Phase Code (I5) and Quadrature Phase (Q5) signals. The L2C and L5 signals are pre-operational and their use is at the users own risk. No commitment of signal availability for L2C or L5 will be made until the signals are declared fully operational by the DoD and available for users. The Baseline 24-Slot GPS constellation definition remains unchanged from the previous edition of the SPS PS while the Expandable 24-Slot GPS constellation definition has improved slightly (see Section ). The SPS PS is updated periodically as GPS modernizes its SPS signal structure.

10 This edition of the SPS PS revises and supersedes the previous edition, published September 2008, and meets or surpasses all performance commitments of the previous edition. Significant changes in this update include the addition of information regarding the pre-operational L2C and L5 signals, and expanded capabilities which allow the total size of operational constellation to grow beyond the previous maximum of 32 Navstar satellites. The L1C signal, the newest GPS signal designed to improve interoperability, will be fielded over time as GPS III satellites populate the GPS constellation and is not addressed in this edition of the SPS PS. It is important to distinguish the operational status of the signals defined in this document. Full Operational Capability (FOC) has been declared for the L1 C/A signal, and it will continue to be provided in accordance with the Federal Radionavigation Plan (FRP) for the foreseeable future.