ECE 456

• Electromagnetics, Optics and Remote Sensing

Topics:

• Principles of Radio Navigation (Reference frames; coordinate transformations; orbital dynamics; time standards)
• Navigation Solution Methods (Newton-Rapshon method; code-range, phase-range, and over-determined solutions)
• System Aspects (Satellite control; orbit determination; time synchronization; receiver types)
• GPS Signal Structure & Observables (Code structure; ephemeredes; navigation message; encrypted vs. non-encrypted signals)
• Errors in the Navigation Solutions (Non-Keplerian effects; harmonic corrections; ionospheric effects; dilution of precision)
• The Future of Global Navigation Satellite Systems (BeiDou; Galileo; GPS modernization)

Python programming for laboratory exercises and several homework exercises.

Written reports are required for each laboratory exercise. A final project report is required at the end of the semester.

1. A first look at the GPS signal and an introduction to the GPS receivers used in the laboratory.
2. Almanac, Orbits, and Satellite Locations.
3. Ephemerides and Satellite Locations.
4. Signal Correlation and Acquisition.
5. Signal Acquisition.
6. Signal Tracking.
7. The GPS Navigation Solution
8. Differential GPS
9. Final project.

* Variety of GPS receivers. * Spectrum analyzers.

Misra and Enge, Global Positioning System: Signals, Measurements, and Performance Second Edition (2006)

Elective

100% Engineering Science

ECE 456 is an elective 4-hour course that gives junior, senior and graduate students in Electrical and Computer Engineering and Aerospace Engineering hands-on experience with global navigation satellite system receivers, such as those for the global positioning system (GPS). Upon completion of the course, students will have written code to interface with a GPS receiver board and will be able to compute an accurate estimate of the receiver’s location based upon the signals broadcast by the GPS constellation of satellites. To reach this goal, students will learn about the basics of navigation, numerical methods to calculate a navigation solution, receiver analysis, error analysis and mitigation through a variety of laboratory activities. The methods learned in this course are general, and can be applied to alternative satellite navigation networks, such as GLONASS, Galileo and BeiDou. A final project will be conducted to allow each student to pursue an advanced topic in GPS navigation. Laboratory excercises are performed in teams and are documented in formal writeups, allowing students to develop teamwork as well as oral and written communication skills.

A. By the time of the first Midterm Exam, students should be able to do the following:

1. Explain the design process, including program goals and constraints, for the development of the US Global Positioning System (GPS). (1, 2, 7)

2. Explain the impacts that the GPS has had on society. (4,7)

3. Use Python to solve numerical problems as demonstrated by writing a Newton-Raphson solver. (1, 7)

4. Use the concept of trilateration to write Python code to solve for a GPS receiver position. (1, 6, 7)

5. Convert between a variety of spatial reference frames (e.g., lat/lon/alt, Earth-centered-Earth-fixed) and write Python code to perform these operations. (1, 7)

6. Determine and model orbital characteristics for a satellite and understand how ephemerides are used to represent different facets of an orbit. (1, 2, 4, 7)

7. Explain the effects of general and special relativity on satellite-based clock and how these effects are accounted for in the design of satellite-based navigation systems. (1, 2, 4, 7)

B. In addition, by the time of the second Midterm Exam, students should be able to do the following:

8. Explain how pseudo-random codes are generated by a maximum length shift (MLS) register and implement an MLS in Python. (1, 6, 7)

9. Understand the auto- and cross-correlation properties of the pseudo-random codes and why they are used in CDMA-type communication systems. (1, 2, 4, 6, 7)

10. Design an acquisition and tracking loop and implement one in Python for use on the GPS signal. (1, 2, 6, 7)

11. Decode the navigation message carried on an individual GPS signal using code written in Python. (1, 2, 4, 6, 7)

C. In addition, by the time of the third Midterm Exam, student should be able to do the following:

12. Demonstrate a basic understanding of error statistics and how errors propagate through the GPS system, affecting the accuracy of a navigation solution (1)

13. Understand the phenomenon of electromagnetic wave propagation through a dispersive medium and its application for communication signals propagating through the earth’s ionosphere. (1, 2)

14. Design a differential navigation system to improve the accuracy of a navigation solution and implement this design in Python. (1, 2, 6, 7)

15. Explain why standalone GPS does not fulfill the need of certain user segments, such as the aviation industry. (4)

16. Understand the specific design considerations and implementation of the Federal Aviation Administration (FAA)’s wide area augmentation system and how it overcomes shortcomings of GPS. (1, 2, 4, 6, 7)

17. Explain the concept of forward error correction as well as Viterbi decoding. (1, 7)

18. Explain the design considerations for alternative and modernized Global Navigation Satellite Systems. (1, 2)

19. Discuss future applications of Global Navigation Satellite Systems (1, 4)

D. By the time of the Final Project, students should be able to do all of the items listed under A, B, and C, plus the following:

20. Demonstrate the ability to perform on a team to complete laboratory activities including design laboratory experiments, implementing engineering solutions, analyzing data, and presenting results in written laboratory documents. (1, 3, 5, 6, 7)

21. Demonstrate the ability to formulate and implement engineering design through completion and presentation (oral and written) of a final project investigating contemporary issues in the field of global navigation satellite systems. (1, 2, 6, 3, 4, 5, 7)