Practical applications of GPS surveying

Transcription

1 Practical applications of GPS surveying WHO WILL TEACH THE COURSE? Kurt L. Feigl, Ph.D., Associate Professor, Department of Geology and Geophysics CAPSULE STATEMENT OF COURSE CONTENT FOR CATALOGS Global Positioning System surveying for field applications: Signals. Coordinate systems. Datums. Cartographic projections. Satellite orbits. Choosing hardware. Strategies for data collection and analysis. Assessing uncertainty. Geocoding satellite images. Integrating data with Geographic Information Systems. Emerging technologies. PREREQUISITES: Calculus and/or elementary vector matrix algebra (Math 210, 211, 221 or equivalent) or consent of instructor Some experience with field mapping, navigation, or orienteering is desirable. Familiarity with computers and/or high-level programming/scripting languages is desirable. This course will NOT be open to freshmen. LEVEL OF COURSE: ADVANCED CROSSLISTING DEPARTMENTS Civil and Environmental Engineering, Geological Engineering, Nelson Institute for Environmental Studies CREDITS: Number: two (2) 8-week modular class beginning week 9. (2.5 hours of lecture per week) x (8 weeks) = 20 hours of instruction HOW TO REGISTER School/College: COLLEGE OF LETTERS AND SCIENCE Department: (420) GEOLOGY & GEOPHYSICS Course: (376) Topics in Geology Session HIH Lecture 003 Practical Applications of GPS Class Number >81196

2 EXPANDED COURSE DESCRIPTION Positioning by multiple measurements of distance (trilateration). How does GPS work? How well does it work? Field mapping exercise: mapping and plotting a campus trajectory. Fundamental geodesy: ellipsoid, geoid, coordinates, datums, cartographic projections.. Review of Linear Algebra. Choosing a surveying strategy: the tradeoff between cost and accuracy. Receiver position from Code Observations (pseudoranges). Baseline computation and M-files. Coordinate Changes and Satellite Position. Receiver position from pseudoranges by two different methods. Clock offsets. Receiver position from phase observations. Kinematic and Rapid Static surveying. Real Time Kinematic surveying. Student presentations of surveying projects. NEED FOR THIS COURSE Many disciplines studying the Earth, its environment and anthropogenic impact on them involve mapping or sampling object in the field. The Global Positioning System allows anyone equipped with a receiver (costing as little as $100) to estimate their position coordinates (latitude, longitude and elevation) to within 10 meters easily. With a more sophisticated instruments and techniques, accuracies of better than 1 cm are possible. Applications range from scientific (e.g., measuring tectonic plates as they move) to the practical ( how do I get back to where I parked my car). If students are to apply these techniques (or supervise others to do so) in tomorrow s world, they should understand the basic technical underpinnings of GPS. RELATIONSHIP TO OTHER UW-MADISON COURSES The proposed new course is complementary to, but distinct from, the following other courses, as described in the supplementary material: Geography 370, Geography 377 (Introduction to Geographic Information Systems), Geological Engineering 302 (Introduction to Electro-Optical and Microwave Remote Sensing Systems), Geological Engineering 303 (Introduction to Remote Sensing Digital Processing), Geological Engineering 304 (Remote Sensing Visual Image Interpretation). On the other hand, I could not identify any significant overlap with any courses in the undergraduate catalog for In assessing overlap, it is important to distinguish between the two similar acronyms, GPS and GIS. The former stands for Global Positioning System and is the topic of the proposed course. The latter stands for Geographic Information System and is downstream in the flow of information. WILL THIS COURSE MEET A REQUIREMENT FOR THE MAJOR IN YOUR DEPARTMENT OR ANOTHER DEPARTMENT? YES, The proposed course 444 would count towards the 34 credits of course work in Geology and Geophysics required for the major. It would also count toward the requirement of credits of upper-level course work.

3 Syllabus Learning Objectives How will students be evaluated? Schedule Textbook To understand the current abilities, future potential, and limiting factors of GPS surveys To master the criteria for choosing instrumentation hardware and analysis software To view practical examples applications of GPS surveying To apply GPS surveying to a practical example of interest To develop critical thinking skills, particularly in spatial reasoning about quantitative data To develop the ability to work in a team, conceive and strategize a project To make judgments of the tradeoff between accuracy and cost Two problem sets involving data analysis with Matlab. One proposal for a project. Project, described above. No final exam. Eight-week modular course beginning week 9 of Spring Semester, Class will meet Tuesdays and Thursdays from 2:30 PM to 3:45 PM. First meeting is tentatively planned for 2:30 PM Tuesday March 13, Strang, G., and K. Borre (1997), Linear algebra, geodesy, and GPS, xvi, 624 p. pp., Wellesley-Cambridge Press, Wellesley, MA. [$65.00] Warning: ordering this book through the usual channels may be slow. Please allow enough time for delivery. If you are interested in taking this course, please order the book in January! You can order it directly from the publisher if you pay by check, but not credit card. See

4 List of Lecture Topics Lecture Number Topic 1 First Class; positioning by multiple measurements of distance (trilateration) 2 How does GPS work? How well does it work? 14.1; 14.2; 14.3 Chapters to read in Strang and Borre 3 Field mapping exercise: Users' guide for receivers 4 Plotting the trajectory on campus map. Estimating velocity & acceleration. Assessing uncertainty, errors, artefacts and gaps. 5 Geometry of the Ellipsoid; Geodetic Reference System; Geoid, Ellipsoid and Datum; World Geodetic System 1984; 6 Review of Linear Algebra I: Vectors; Lengths and Dot Products; Planes 1.1; 1.2; 1.3 Users' guide for software 14.7; (skip 14.8); 14.9; 14.10; 14.11; Review of Linear Algebra II: Matrices and Linear Equations; Heights by least squares; weighted least squares 1.4; 8.1, Choosing a surveying strategy: the tradeoff between cost and accuracy Handout 9 Receiver position from Code Observations (pseudoranges) Baseline computation and M-files; Coordinate Changes and Satellite Position 11 Receiver position from pseudoranges by two different methods, clock offsets 15.1; Receiver position from phase observations 15.4; ; 15.7 (pp only); 15.8 ( pp only) 13 Kinematic and Rapid Static surveying handout 14 Real Time Kinematic surveying handout 15 Student presentations of surveying project 16 Student presentations of surveying project

5 Description of Project Software Working in teams of two, the students will use GPS receivers to perform a survey of interest to them. They will then present the results of the survey to the class in a short, 15-minute oral presentation, as a team of two. Examples of projects might include: Locations of parking spots for a certain type of vehicle (e.g., bicycle, handicap van, etc) available on campus at the time(s) of the survey(s). Establishing a grid for environmental research on University Lands, e.g. Arboretum Monitoring the trajectory, including estimates of velocity and acceleration for recreational vehicles (e.g., bicycles, rowing shells, sailboats, canoes, skateboards, cross-country skiing, etc.) Locating sampling, measurement, or observation points for geologic, biologic or anthropological research project. Prior to undertaking the project, each student will write, as an individual, a brief proposal of the problem to be addressed and the technical approach for meeting it, including the trade-off between cost and accuracy. Matlab Student Version Mathworks MATLAB 7 Student Version R14 with Service Pack 3 (Student Sales Only) for Mac/Linux/Win CD. License Valid as long as the Student is a registered Student in a Degree-Granting Institution. Scripts Available free of cost from Strang and Borre at Google Earth Plus Intended for personal use, Google Earth Plus is an optional, upgraded version of Google Earth available for $20. Why buy it? In addition to the basic features, Google Earth Plus includes: * GPS data import - read in tracks and waypoints from select GPS devices o Note 1: Verified support for Magellan and Garmin devices only o Note 2: Does not support export of tracks or waypoints to a GPS device * Higher resolution printing (greater than screen resolution). * Annotation adds draw/sketch tools for richer annotations (can be shared as KML). * Data importer read address points from.csv files. To purchase Google Earth Plus, download Google Earth at Then run Google Earth and select "upgrade" from the "help" menu. Excel or equivalent For manipulating data tables in Comma-Separated Values (CSV) format. ARC GIS (optional) Student license $100

6 Hardware Computer Camera If you own a laptop, please bring it to class on the meeting after the field mapping exercise. If you own a digital camera with a USB cable, please bring it to class for the field mapping exercise. GPS receivers To be provided by the department of Geology and Geophysics in cooperation with Geological Engineering program.