Course 373: GPS-Based Attitude Determination

Instructor	Dr. Penina Axelrad, University of Colorado
About This Course	This course addresses the theory and application of high precision GPS carrier phase measurements to attitude determination of ships, aircraft and spacecraft. Case studies are presented for a variety of applications and GPS attitude instruments.
Objectives	To provide an understanding of GPS carrier phase observations and the use of carrier phase for GPS-based attitude determination To describe the error sources in GPS-based attitude determination To provide solution algorithms for GPS and integrated GPS/Gyro attitude solutions To discuss ambiguity resolution To present case studies for land, marine airborne and space applications
Prerequisites	The ideal preparation for this course is Course 356: GPS Operation for Engineers, or equivalent GPS experience. Course 122: GPS Fundamentals and Enhancements and Course 217: Introduction to Differential GPS, combined, provide an acceptable background.
Course Schedule	DAY 1 *Dr. Penina Axelrad*
	8:30 - GPS-Based Attitude Determination • Basic principles of operation • Historical perspective • Relationship between kinematic survey and attitude determination 9:45 - GPS Equipment Configurations • Reference frames • Attitude representations • Attitude determination problem statement 11:00 - GPS Equipment for Attitude Determination • Requirements and configuration • Specific attitude receiver features • Non-dedicated GPS sensor configurations 12:00 - Lunch on your own 1:30 - Carrier Phase Measurements & Models • What are they? • How they are formed in the receiver • Measurement models • Single and double differences on very short baselines 2:45 - Error Sources • Multipath • Oscillator stability • Receiver tracking errors 4:00 - Ambiguity Resolution and Baseline Calibrations • Problem definition for attitude determination • Use of antenna baseline constraints • Search techniques • Motion-based techniques 5:00 - Day One Ends
	DAY 2 *Dr. Axelrad*
	8:30 - GPS Attitude Solution • Two step method • Deterministic and least squares solutions • Linearized direct attitude solution 9:45 - Attitude Solution Accuracy • Baseline errors • Satellite and baseline geometry, ADOP • Alignment calibration 11:00 - Attitude Filters & GPS/Gyro Integration • Kalman filter solution • GPS and gyro error models • Expected performance 12:00 - Lunch on your own 1:30 - Space Applications: Case Study I • Receiver hardware • Three-axis stabilized satellites • Spinning satellites • Coarse attitude determination • Integrated GPS/gyro solutions 2:45 - Marine Applications: Case Study II • Heading and alignment • Multi-receiver configurations • GNSS based attitude determination 4:00 - Aircraft Applications: Case Study III • Dynamics, wing flexure, vehicle modes • Application to landing systems 5:00 - Course ends
Attendee Quotes	"This course information will be helpful in my algorithm development, simulations, and interpretation of results. Very well done." - Roger Hart, Motorola "Those sessions that covered solutions/applications for SNR-measurements and non-dedicated GPS systems will be very useful to me." "A breath of fresh air! Enjoyed the class." "Excellent teaching style. Best tutorial I sat in." "I will be able to evaluate attitude systems now." "This course will help me to make a GPS-based attitude estimator."
Continuing Education Units	1.2 (12 hours)
Materials You Will Keep	• A CD-ROM with PDF electronic course notes used during the course. Bringing a laptop is highly recommended; power access will be provided. Return to top of page