Satellite Geodesy

Year: III Semester: VI

Course Objectives:

a. To provide up-to-date theoretical knowledge on satellite geodesy, gravimetric, magnetic, and seismic surveys, GNSS, and laser altimetry.
b. To provide knowledge on instrumentation for the measurement of the above.
c. To carry out observations for GNSS, gravimetric, and other surveying techniques.

Course Detail:

1. Geometrical Use of Artificial Satellites (5 hrs)

1.1 Astro-triangulation
1.2 Satellites and cameras
1.3 Measurement of satellite distances
1.4 Satellite and Lunar Laser Ranging

2. Principle GNSS (7 hrs)

2.1 Introduction
2.2 GNSS signals
2.3 GNSS Networks (GPS, GLONASS, etc.)
2.4 GNSS Instruments
2.5 Instrument Calibration

3. GNSS Observation (10 hrs)

3.1 Fundamentals of GNSS
3.2 Doppler Observation
3.3 CORS (Continuously Operating Reference Stations)
3.4 DGPS (Differential GPS)
3.5 RTK (Real-Time Kinematic), PPK (Post-Processed Kinematic)
3.6 Adjustment of Observations
3.7 WGS84 System

4. GNSS and Laser Altimetry (10 hrs)

4.1 ITRF, Statics, Semi-dynamic, and Dynamic Coordination Systems
4.2 Reference system, Structure, and uses of instruments
4.3 Observables
4.4 System Biases and Errors
4.5 Mathematical Models
4.6 Static and Kinematic Positioning
4.7 Specification and Field Surveys
4.8 GNSS Networks and Computation of Observations
4.9 Laser Altimetry

5. Application of GNSS (8 hrs)

5.1 Navigation – Land, Air, Sea, and Space
5.2 Location Services – Boundary, IMS (Integrated Monitoring System)
5.3 Time Service
5.4 Deviation of Vertical
5.5 Specification

6. Data Processing (5 hrs)

6.1 Processing and Adjustment of Data in Different Modes of Observations

Exercises (15 hrs):

1. Observations for DGPS, RTK, or PPK (During field work).
2. Precise measurement using GNSS receiver.

Recommended Reading and Reference Books:

1. G. Bomford, Geodesy, Oxford, UK.
2. Torge, Geodesy.
3. Chris Rizos, Principles and Practice of GPS Surveying, University of N.S.W., Australia.
4. J.R. Smith, Introduction to Geodesy, History and Concept of Modern Geodesy, John Wiley & Sons Inc., 1997.
5. A. Leick, GPS Satellite Surveying, John Wiley & Sons Inc., 1995.
6. G. Strang and K. Borre, Linear Algebra and GPS, Wellesley-Cambridge Press, 1997.

Examination Scheme

Model Questions

Very Short Questions [4×2 = 8]

1. What is GNSS and GNSS signal?
2. How do you measure the distances between the receiver and GNSS satellites?
3. Define PPP for the position of the instrument. Describe the methods of correction of data for such observations.
4. How do you measure the position of boundary markers?

Short Questions [8×4 = 32]

5. List the principles of GNSS positioning.
6. Describe briefly the modern astro-triangulation technique for the measurement of the position of celestial bodies.
7. Define RTK and describe how it is used to establish control points.
8. What are CORS stations, and list the uses of CORS stations.
9. List GNSS networks in operation and describe one network.
10. Define semi-dynamic coordinate systems and how they differ from static coordinate systems.
11. Describe the uses of GNSS in the determination of the deviation of verticals.
12. Describe the system biases and errors in GNSS observation for control points.

Long Questions [2×10 = 20]

13. Illustrate briefly how DGPS surveys are carried out, connecting national control points.
14. Describe briefly GNSS receivers and satellite networks.
    OR
    Define satellite and lunar ranging. Describe a lunar ranging technique briefly.