Global Positioning Systems (GPS) and Global Navigation Satellite Systems (GNSS)

Global Navigation Satellite Systems (GNSS) are constellations of Earth-orbiting satellites that provide autonomous geo-spatial positioning, navigation, and timing data to electronic receivers anywhere on or near the planet. A receiver determines its precise location (latitude, longitude, and altitude) by intercepting signals from multiple satellites and applying computer algorithms, primarily based on the principle of trilateration, to calculate the time difference between signal transmission and reception. While the United States' Global Positioning System (GPS) is the most widely known example, GNSS is the broader, generic term that also encompasses other global systems like Russia's GLONASS, Europe's Galileo, and China's BeiDou, forming a critical technological foundation for countless applications ranging from personal navigation and logistics to scientific research and the synchronization of critical infrastructure.

  1. Introduction to GNSS
    1. Defining GNSS and GPS
      1. Definition of GNSS
        1. Definition of GPS
          1. Relationship Between GNSS and GPS
            1. Overview of Satellite Navigation Principles
            2. Historical Development of Satellite Navigation
              1. Early Navigation Concepts
                1. Radio Navigation Systems
                  1. LORAN Systems
                    1. Decca Navigation System
                    2. TRANSIT System
                      1. Development and Purpose
                        1. Operational Principles
                          1. Limitations and Lessons Learned
                          2. Timation Program
                            1. Atomic Clock Development
                              1. Space-Based Timing Experiments
                                1. Contributions to Modern GNSS
                                2. GPS Development
                                  1. Military Origins and Requirements
                                    1. System Design and Implementation
                                      1. Civilian Access and Selective Availability
                                        1. Key Deployment Milestones
                                      2. Core Functions of GNSS
                                        1. Positioning
                                          1. Geographic Location Determination
                                            1. Absolute Positioning
                                              1. Relative Positioning
                                              2. Timing Services
                                                1. Precise Time Distribution
                                                  1. System Synchronization
                                                    1. Time Transfer Applications

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                                                2. Fundamental Concepts