Course 217: Introduction to Differential GPS

Instructor	Dr. Chris Hegarty, MITRE
Objectives	• To provide an intensive overview of DGPS system design and operation concepts. • To provide a background in DGPS system test and evaluation theory and techniques. • To provide some of the latest applications and test results using DGPS. • To present representative DGPS implementations for aviation, space, land and marine.
Prerequisites	Familiarity with GPS and basic receiver operation, such as that provided by NavtechGPS Course 111 or Course 122. Familiarity with engineering terms and data representation.
Course Schedule	8:30 - DGPS Overview Local-area, regional-area, wide-area architectures Code vs. carrier phase based systems Pseudolites Performance overview 9:45 - Differential Error Sources Satellite ephemeris errors Satellite clock errors Selective availability Ionospheric and tropospheric delay Multipath Receiver internal noise and biases 11:00 - Observable Modeling Code pseudorange and carrier phase outputs Code-minus-carrier observables Carrier smoothed code operation Double difference operation System error budgets 12:00 - Lunch on your own 1:30 - DGPS Design Considerations Range vs. navigation domain corrections Data links; Pseudolites Reducing major error components Ambiguity resolution 2:45 - DGPS Case Studies I RTCM SC104 message format USCG maritime DGPS and National DGPS (NDGPS) Commercial satellite-based systems 4:00 - DGPS Case Studies II Wide Area Augmentation System (WAAS) Local Area Augmentation System (LAAS); pseudolites RINEX format CORS network for precise positioning (survey) Precise time transfer 5:00 - Course Ends
Continuing Education Units	0.6 (6 hours)
Materials You Will Keep	• A notebook containing copies of all presentation materials used during the course. • A copy of the following text: The Global Positioning System, Vol. IV, ION Monograph, 1993. • NavtechGPS CD-ROM containing a variety of GNSS references. Return to top of page