1. Retrieval Analysis and Methodologies in Atmospheric Limb Sounding Using the GNSS Radio Occultation Technique
PhD Defence by
Stig Syndergaard

2. Content of presentation
The GNSS radio occultation principle
Data processing and exemplar results
Violation of spherical symmetry assumption
Severe weather gradients
Earth’s oblateness
Ionosphere calibration of data
Conclusion and prospects

3. The GPS constellation 24 satellites Six 12 hour orbits
Altitude: km
Inclination: 55º
Transmit dual frequency signals

8. Content of presentation
The GNSS radio occultation principle
Data processing and exemplar results
Violation of spherical symmetry assumption
Severe weather gradients
Earth’s oblateness
Ionosphere calibration of data
Conclusion and prospects

13. Content of presentation
The GNSS radio occultation principle
Data processing and exemplar results
Violation of spherical symmetry assumption
Severe weather gradients
Earth’s oblateness
Ionosphere calibration of data
Conclusion and prospects

18. Content of presentation
The GNSS radio occultation principle
Data processing and exemplar results
Violation of spherical symmetry assumption
Severe weather gradients
Earth’s oblateness
Ionosphere calibration of data
Conclusion and prospects

19. Correcting for the Earth’s oblateness

20. Earth’s oblateness
Before correction
After correction

21. Content of presentation
The GNSS radio occultation principle
Data processing and exemplar results
Violation of spherical symmetry assumption
Severe weather gradients
Earth’s oblateness
Ionosphere calibration of data
Conclusion and prospects

24. Model calculation of retrievals of the temperature in the case of a typical day-time, solar maximum ionosphere

31. GPS/MET occultation no. 259, day 35, 1997

33. Content of presentation
The GNSS radio occultation principle
Data processing and exemplar results
Violation of spherical symmetry assumption
Severe weather gradients
Earth’s oblateness
Ionosphere calibration of data
Conclusion and prospects

37. 14 days of GPS/MET occultations