Research group of Astronomy and GEomatics. gAGE

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Master's Degree in Aerospace Sciences and Technology (MAST) 2023/2024

Second Semester - Spring

The course of Global Navigation Satellite System (GNSS) enters in detail in the study of the data and processing algorithms related to Galileo, GPS, GLONASS, and BeiDou constellations. The theoretical foundations are presented from a conceptual point of view and are complemented with guided exercises that conducted by a tool of software specifically designed for the processing and analysis of GNSS data known as the ESA / UPC GNSS - Lab Tool suite (gLAB). The training is intended to provide, from the first moment, operational capabilities in the use instrumental of the concepts and techniques for the treatment of data GNSS.
The course develops the contents of the GNSS Data processing book “Volume 1: Fundamentals and Algorithms” and “Volume 2: Laboratory Exercises”, edited by the European Space Agency (ESA), whose authors are the instructors of the course. The materials of the course include the mentioned book (in format PDF) and one booklet with all the slides of the course in format PDF), as well as the tools software that is used in the laboratory exercises (gLAB tool suite).

Theory Lectures


Lecture 1:  Introduction to GNSS (1h)

  • An Intuitive Approach to GNSS Positioning
  • A Deeper Analysis of 2D Pseudorange-Based Positioning
  • Translation to 3D GNSS Positioning


Lecture 2: GNSS Architecture (1h)

  • GNSS Segments

          Space Segment
          Control Segment
          User Segment

  • GNSS Signals

         GPS Signals
         GLONASS Signals
         Galileo Signals
         BeiDou Signals

  • Summary of GNSS Signals

Lecture 3: Overview of GNSS Positioning Techniques (3h)

  • Standalone Positioning

  • Code based Differential Positioning

         DGNSS
         GBAS
         SBAS

  • Carrier based Differential Positioning  

         RTK and NRTK
         PPP

 

  • Commercial Services


Lecture 4: GNSS Time Reference Systems and Frames (3h)

  •  Time and Reference Frames

       Time
       Reference Systems and Frames
       GNSS Reference Frames
       Cartesian and Ellipsoidal Coordinates
       Regional Datums and Map Projections

Lecture 5: GNSS Measurements and Data Pre-processing (4h)

  • Combinations of GNSS Measurements

       Combining Pairs of Signals
       Combining Trios of Signals

  • Measurement Features and Noise

       Receiver Noise
       Multipath
       Carrier Smoothing of Code Pseudoranges
  • Carrier Phase Cycle-Slip Detection
       Examples of Multi-Frequency Cycle-Slip Detectors
       Examples of Single-Frequency Cycle-Slip Detectors


 Lecture 6: Satellite Orbits and Clocks (3h)

  • Satellite Orbit

       Keplerian Elements (Two-Body Problem)
       Perturbed Motion
       GNSS Broadcast Orbits

  • Computation of GNSS Satellite Coordinates and Clock Offsets

      Computation of GPS, Galileo and BeiDou Satellite Coordinates and Clocks
      Computation of GLONASS Satellite Coordinates and Clocks
      Computation of Precise GNSS Satellite Coordinates and Clocks
      Computation of Coordinates from Almanac Data


Lecture 7: Code Pseudorange Modelling (4h)

  • Linear Model and Prefit-Residuals

  • Code Measurements Modelling

        Geometric Range Modelling
        Relativistic Path Range Correction
        Relativistic Clock Correction
        Instrumental Delays
        Atmospheric Effects Modelling

  • Example of Computation of Modelled Pseudorange

Lecture 8:  Solving Navigation Equations (4h)

  • Linear Model: Navigation Equations

  • Least Squares Solution.

  • Weighted Least Squares and Minimum Variance Estimator

  • Kalman Filter

       Examples for Static and Kinematic Positioning

Lecture 9:  Precise Point Positioning (3h)

  • Additional Model Terms for PPP

       Carrier Phase Wind-up Effect
       Antenna Phase Centre Correction
       Earth Deformation Effects Modelling

  • Linear Observation Model for PPP

  • Parameter Estimation: Floating Ambiguities

  • Accelerating the Filter Convergence: Fast PPP



Practical Lectures

Tutorial 0. Introduction to gLAB Tool Suite (1h)

Tutorial 1. UNIX Environment Tools and Skills (1h)

Tutorial 2. Measurements Analysis and Error Budget (3h)

Tutorial 3. Model Components Analysis (3h)

Tutorial 4. Detailed Code Measurements Modelling (3h)

Tutorial 5. Solving Navigation Equations (3h)

Tutorial 6. Kinematic orbit estimation of a LEO satellite

 
Evaluation system:

Students have the option to choose between:

-        Taking a single final exam (100% of the mark).

-        A course work (50% of the mark) and a reduced final exam (50%).