Briefly describe what GLONASS is. How does it compare with GPS?
What is WGS84? How is it defined? How is it maintained? How does it
relate to local geodetic datums?
What is ITRF? How is it defined? How is it maintained? How does it
vary from year to year?
Compare and contrast the operations of GPS "surveying" and
GPS "navigation", with particular emphasis on applications, hardware,
tracking scenario, data processing, etc.
Distinguish between "Selective Availability" and "Anti-Spoofing".
What are the implications for military and civilian users?
Distinguish between gross, systematic and random error. Give some
examples of each for the GPS system.
What is the positioning performance of GPS "surveying"?
What factors are responsible for this accuracy?
Make some comments on different levels of accuracy for GPS "surveying".
What distinguishes these different levels of accuracy?
Using a suitable satellite orbit package (e.g. the "mission planning"
module within commercial GPS software), experiment with the determination
of satellite coverage for different sites, for different cutoff angles,
at different times of the day, at the same time of day on different days
and at different sites, etc. Comment on your findings.
How is GPS Time defined? How is GPS Time maintained within the Space
Segment?
Back to Chapter 2 Contents© Chris Rizos, SNAP-UNSW, 1999