Geoscience 444
Practical Aspects of GPS Surveying
Photo of a geodetic benchmark in Honduras by Neal Lord
Kurt Feigl
Associate Professor
Department of Geoscience
Description of Course
Capsule statement of course
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 highlevel
programming/scripting languages is desirable.
 This course is NOT open to freshmen.
LEVEL OF COURSE: ADVANCED
CROSSLISTING DEPARTMENTS
 Civil and Environmental Engineering
 Geological Engineering
 Nelson Institute for Environmental Studies
CREDITS:
Number: two (2)
7week modular class beginning week 10.
(2.5 hours of lecture per week) x (7 weeks) + 2 x (4hour field
exercises) = 25.5 hours of instruction
HOW TO REGISTER
GEOSCI 444001 LEC (55572) Pract Appl of GPS Surveying
G L E 444001 LEC (45403) Pract Appl of GPS Surveying
ENVIR ST 444001 LEC (46124) Pract Appl of GPS Surveying
GEOLOGY 444001 LEC (55572) Pract Appl of GPS Surveying
CIV ENGR 444001 LEC (63268) Pract Appl of GPS Surveying
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 Mfiles. 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 UWMADISON 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 ElectroOptical 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 20052007. 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 course 444 does
count towards the 34 credits of course work in Geology and Geophysics
required for the major. It also counts toward the requirement of
1215 credits of upperlevel course work.
Syllabus
Learning Objectives
 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
How will students be evaluated?
 Two problem sets involving data analysis with Matlab.
 One proposal for a project.
 Project, described above.
 No final exam.
Schedule
 Sevenweek modular course beginning week 10 of Spring Semester,
2010.
 Class will meet Tuesdays and Thursdays from 2:30 PM to 3:45 PM.
 Location for all class meetings is Room 1249 of Engineering Hall
(ENGR)
 First meeting is 2:30 PM Tuesday March
16, 2010.
 Field exercise I is from 1:00 to 5:00 PM Saturday April 10th, 2010
 Field exercise II is from 1:00 to 5:00 PM Saturday May 1st,
2010
 Student presentations of projects are tentatively scheduled for
6:00 PM  9:00 PM Tuesday May 11th, 2010.
 Office Hours: Tuesdays 4:00 to 5:00 PM in Room 1249 of
Engineering Hall
First Class; positioning
How does GPS work? How well does it work?
Geometry of the Ellipsoid; Geodetic Reference System; Geoid, Ellipsoid
and Datum; World Geodetic System 1984; Changing Datum
Preparing for a field survey
Field Exercise 1: Point Positioning with a single receiver
Introduction to Matlab: functions, scripts, plots, etc.
Review of Linear Algebra I: Vectors; Lengths and Dot Products; Planes
Review of Linear Algebra II: Matrices and Linear Equations; Heights by
least squares; weighted least squares
Choosing a surveying strategy: the tradeoff between cost and accuracy.
Expectations for student projects.
Receiver position from Code Observations
Precise point positioning for stationary receiver.
Field Exercise 2: Relative Positioning with three receivers
Precise point positioning for moving receiver
Relative positioning from phase observations for stationary receiver.
Rapid Static Positioning
Review Q & A.
Student presentations of surveying
project
Description of Project
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,
15minute 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, crosscountry 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 tradeoff between cost
and accuracy.
 Locations for procuring pizza near campus. Click
here to download KMZ file for Google Earth.
 Locations of bike racks on campus. Click here to download
KMZ file for Google Earth.
Documentation
Textbooks

Strang, G., and K. Borre (1997),
Linear algebra, geodesy, and GPS, xvi,
624 p. pp., WellesleyCambridge 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 http://wwwmath.mit.edu/~gs/books/gps.html 

Leick, A. (2004). GPS satellite
surveying. Hoboken, NJ, John Wiley.

Software
Computer Aided Engineering Center
Matlab
Tutorials
Student Version
Scripts
 The Matlab scripts described in Strang and Borre's textbook are
available free of cost from Strang and
Borre at http://kom.aau.dk/~borre/matlab/
 The Easy Suite  Matlab code for the GPS newcomer  by Kai
Borre. Matlab code for reading RINEX files, determining a pseudorange
point position, calculating a carrierphase baseline solution,
doing a Kalman Filter baseline solution, checking for cycle slips and
receiver clock resets, estimating ionospheric delay, plotting receiver
clock drift, and more... The technical paper which describes this
Matlab code is published in
GPS Solutions, Volume 7, Number 1, 2003, pp 4751, "The Easy Suite 
Matlab code for the GPS newcomer" by Kai Borre. The Matlab code
is available at the author's website: http://www.gps.auc.dk/~borre/easy
 Download from here into your
own matlab directory
 matlab444.tgz
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 http://earth.google.com/earth.html . Then run Google
Earth and select "upgrade" from the "help" menu.
Excel or equivalent
For manipulating data tables in
CommaSeparated Values (CSV) format.
ARC GIS (optional)
Student license $100
http://www.lic.wisc.edu/esri/StudentAV9.htm
Earth Bridge
It's a freeware (or donationware)
program that listens to NMEA GPS data
stream on a serial port and sends the data to a google earth .kml file
along with a .net service which lets google earth know when the file is
automatically updated.
Neal has tried it with the Garmin Etrex and another GPS receiver and it
seems to work well with the free version of google earth. The
earth
bridge software can be found at
http://mboffin.com/EarthBridge
GeoRobo
For tagging digital photos with GPS coordinates. No need for tricky
connections between the receiver and the camera. Clever!
http://www.robogeo.com/home/
GPSBabel
For translating data from one format to another....
http://www.gpsvisualizer.com/gpsbabel/
Automatic Point Positioning Service (APPS)
Estimate position for a single GPS station with submeter precision
from a RINEX file containing (preferably dualfrequency) phase data
from a geodetic  grade GPS receiver. The receiver may be moving.
http://apps.gdgps.net
Online Positioning User Service (OPUS)  Static
Estimate relative position for a fixed station with with respect to
several stations of the CORS network in the US. Requires a RINEX file
containing dualfrequency phase data from a geodetic  grade GPS
receiver. Two different solutions are offered: Static
(OPUSS) and
Rapid Static (
OPUSRS).
http://www.ngs.noaa.gov/OPUS
Hardware
Computer
If you own a laptop, please bring it to
class on the meeting after the field mapping exercise.
Camera
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. Click
here
for more information about the GPS facility.
Data Sets
UW  Madison Campus
Driving from Berekeley campus to the SFO
airport
Trimble 4600 LS
Neal was able to automate the Trimble
nav file to RINEX obs and nav files. The converted 4600LS files
are in a file called
4600Rinex.zip
We haven't looked to see if any of the data from the three receivers
overlap.
Class Project: Presentations from Previous Years' Students
2008
Power Point Files
KML and KMZ Files for Google Earth