Satellite Surveying

LEARNING OUTCOMES

The aim of this course is to give a deep understanding of the fundamental principles of satellite surveying using GNSS (Global Navigation Satellite Systems). Emphasis is given in geodetic satellite surveying, i.e. techniques offering cm level precision. The students learn how to choose the appropriate satellite receiver and measurement technique in order to fulfill the requirements of each work. They also learn how to plan and conduct GNSS measurements understanding potential error sources (multipath, E/M interferences etc.) as well as how to process the satellite observations and estimate coordinates and heights in the local reference systems.

Upon successful completion of the course the students will be able to:

• understand the operation principles of GPS and GNSS receivers
• understand the GPS signal structure (carrier frequencies, PRN codes, navigation message)
• understand the basic satellite measurement methods (absolute, relative, static- kinematic, RTK)
• understand the basic error sources that affect the GNSS measurements as well as the methods used to mitigate these errors
• understand the pseudorange and phase measurements and the mathematical models for data processing (single- double-differences, ambiguity resolution)
• understand the network-based methods (Single-base, VRS, MAC, FKP)
• plan and conduct geodetic GNSS measurements
• process the satellite observations and estimate coordinates with accuracies on the mm or cm level
• apply network-based techniques using networks of permanent reference stations like e.g. the Hellenic Positioning System

 

General Competences

• Search for, analysis and synthesis of data and information, with the use of the necessary technology
• Adapting to new situations
• Working independently
• Team work
• Production of new research ideas

 

SYLLABUS

Theoretical part:

1. Introduction to satellite surveying
2. Global Navigation Satellite Systems (GPS, GLONASS, GALILEO)
3. Coordinate and time reference systems used in satellite surveying.
4. GPS signals (carrier frequencies, PRN codes), orbital elements.
5. GPS receivers, receiver and antenna technology.
6. Surveying techniques (autonomous-relative, static-kinematic, real-time techniques, RTK).
7. Error sources and elimination methods.
8. Mathematical models for carrier-phase processing (single-, double- and triple- differences), fast ambiguity resolution algorithms.
9. Satellite based augmentation systems (EGNOS and WAAS).
10. GNSS networks: design, measurement, baseline reductions and tie to the national Geodetic Reference System.
11. Determination of orthometric heights by means of GNSS.
12. Continuously Operating Reference Stations networks.
13. Network-based techniques (VRS, FKP, MAC) used in CORS networks like the Hellenic Positioning System (HEPOS).

 

Laboratory part:

1. Measurement planning using GNSS planning software
2. Field measurements with GPS and GNSS receivers (static, RTK)
3. Set up of a geodetic GNSS receiver, measuring and converting the antenna height
4. Processing of carrier phase observations (baseline reduction, evaluation of reliability), network adjustment, geodetic datum transformation, estimation of orthometric heights.

 

STUDENT PERFORMANCE EVALUATION

Assessment language: Greek (English for ERASMUS students upon request)
Performance evaluation method:
• Final Written Exam (80% of the final grade) of graded difficulty, which include short-answer questions, open- ended questions and solving simple problems.
• Evaluation of laboratory work (20% of the final grade) which includes exercises (processing of GNSS data).

The evaluation criteria have been presented to the students before the final examination. Students can see their evaluation upon request and receive clarifications on their grades.

 

ATTACHED BIBLIOGRAPHY

– Suggested bibliography (in Greek):
1. Φωτίου Α., Πικριδάς Χ., 2012. GPS και Γεωδαιτικές Εφαρμογές. Εκδόσεις Ζήτη, Θεσσαλονίκη.
2. Δερμάνης Α., 1999. Διαστημική Γεωδαισία και Γεωδυναμική – GPS. Εκδόσεις Ζήτη, Θεσσαλονίκη

– Suggested bibliography (in English):
1. Hofmann-Wellenhof B., Lichtenegger H., Wasle E., 2008. GNSS: Global Navigation Satellite Systems – GPS, GLONASS, Galileo, and More. Springer-Verlag, Wien/New York.
2. Leick A., 2004. GPS Satellite Surveying. 3rd edition, John Wiley & Sons, New Jersey.
3. Seeber G., 2003. Satellite Geodesy. 2nd edition, De Gruyter, Berlin.