GIS for Environmental Science

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GIS for Environmental Science

• ENSC 3603
• Class 10
• 2/12/09

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Today's Objectives

• GPS review, Garmin GPS, Trimble Planning
  software
• Review questions for Exam 1

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GPS

• Global Positioning System

Consists of 24 satellites orbiting about 12,000
miles above the Earth
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GPS
P Consists of 24 satellites orbiting about 12,000
miles above the Earth, and five ground stations
to monitor and manage the satellite
constellation. P Cost 12 billion Dollars
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GPS
Based on ground based navigation systems
developed in the early 1940s. Inspiration came
for GPS as U.S. scientists notice the Doppler
effect on the Soviet Sputinik in 1957. Reagan
announced that the GPS system would be made
available to the public when complete after the
Soviets shot down airline KAL 007 with 267
people on board in 1983. 1994, complete
constellation of 24 satellites was in
orbit. 2000, selective availability discontinued.
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GPS and Landsat satellites
Earth Diameter 7,926 mi
LS 570 mi
GPS 12,000 mi
www.jesseshunting.com/site/gps.html
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GPS

• 1- The basis of GPS is triangulation from
  satellites.
• 2- To triangulate, a GPS receiver measures
  distance using the travel time of radio signals
• 3- To measure travel time, GPS needs very
  accurate timing which it achieves with some
  technology tricks.
• 4- Along with distance, you need to know exactly
  where the satellites are in space. High orbits
  and careful monitoring are essential.
• 5- Any delays the signal experiences as it
  travels through the atmosphere must be corrected.
• (www.trimble.com)

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GPS
Peter H. Dana, Ph.D. http//wwwhost.cc.utexas.edu/
ftp/pub/grg/gcraft/notes/gps/gps.html
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GPS
Peter H. Dana, Ph.D. http//wwwhost.cc.utexas.edu
/ftp/pub/grg/gcraft/notes/gps/gif/difnav.gif
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GPS Errors
Peter H. Dana, Ph.D. http//wwwhost.cc.utexas.edu
/ftp/pub/grg/gcraft/notes/gps/gif/gpserror.gif
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Sources of Real-Time DGPS
U. S. Coast Guard Beacon Local FM
Signals Satellite-Based Differential
Corrections Purchase a Base Station
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Coast Guard Maritime Differential GPS Site
Coverage for Arkansas
U.S. CoastGuard http//www.navcen.uscg.mil/dgps/co
verage/ark.htm
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OmniSTAR Satellite Regional Coverage
http//www.omnistar.com/namerica.html
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GPS Accuracies and Costs
Peter H. Dana, Ph.D. http//www.utexas.edu/depts/g
rg/gcraft/notes/gps/gif/gpsapps.gif
PGeneral Navigation 100 to 1000
100m PDGPS 2500 to
5000 1m PL1 Carrier Phase Survey 10,000
0.1m PL1L2 Carrier Phase Survey 15,000
0.01m 1cm accuracy systems
30,000 0.001m
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GPS

• Slide show at
• http//www.colorado.edu/geography/gcraft/notes/gps
  /gps_f.html
• http//www.trimble.com/gps/ this requires
  Shockwave and may not work on the lab computers
  at this time
• Lo, 2002 p. 52

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GPS
Garmin eTrex Legend Cx Owners manual PDF
P http//www.garmin.com/manuals/972_OwnersManual.p
df
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P. 3
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P. 3
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Quit
Menu
P. 3
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P. 3
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Trimble Office, Planning
Graphs, PDOP Sky Plot Satellites on
2/14/07 Satellite Selection Visibility GPS G04,
5, 6, 10,14, 24,30, World map http//www.trimble.c
om/planningsoftware.shtml
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Maps

• A map's function is to communicate geographic
  information
• Types
• General - show locational or positional
  data. e.g. Atlas
• Thematic shows the structure and distribution
  of phenomena
• Qualitative -depict different features with
  different symbols according to some attribute.
  e.g. Soil series maps
• Quantitative - show differences in features'
  numeric attributes. e.g. Population density for
  each county in a state

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Review
1. What is a GIS? 2. Data is one of the four
components of a GIS as an information System.
Name the other three. 3. What kind of analysis
would be best to create a land suitability map
for agricultural development if you had
information about soil, topography and land
cover? a. Overlay analysis, b. Query, c. Network
analysis, d. Proximity analysis 4. Conic is one
of the three main types (categories) of
projections. Name the other two. 5. A small
scale map is best to represent the University of
Arkansas main campus. a. True, b. False 6. The
last phase of GIS development is Management. What
are the other two phases? 7 Surface is a type
of GIS data. Name the other two types. 8. What
is the purpose of a map projection? 9. What is a
Coordinate system?
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Review
10. Why is the Universal Trasnsverse Mercator
(UTM) a good coordinate system to use for
Arkansas? 11. A ______________ data model treats
geographic space as populated by discrete and
identifiable objects. 12. A__________________
data model treats geographic space as populated
by one or more spatial phenomena, which are
real-world features that vary continuously over
space with not specific extent. 13. A description
of our view of the real world is a ________
__________. 14. Of the two common types of maps,
a ___________ map shows locational or positional
data while a_____________ map shows structure and
distribution of phenomena. 15. What is a maps
function? 16. a) A _________________ is a spatial
object with specific properties b) A
_________________ is a description of 16a
above. c) A _________________ is spatial
association among the answer of 16a.
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Review
17. In Topological Overlay Operators for polygon
on polygon _________________ keeps all
features in both layers _________________
Keeps only parts of the first layer falling
within the second layer _________________ Cuts
out a piece of the first layer based on the
second, Cookie Cutter. 18. Points are one of the
three vector data graphical elements (basic
geometry types), name the other two? 19. The
vector data graphical elements are also known as
_______ _______ 20. In GIS spatial
relationships, When neighboring polygons share
a boundary it is called ___________________
The inclusion of one spatial object within
another is called __________________ Linkages
among spatial objects is called
____________________
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Review
21. A pixel or _________is the smallest unit of
information available in an image or raster
map. 22. One image compression technique is
called quad tree, name another technique. 23.
Raster data model is best for a) Topology b)
Precision if graphics c) Continuous space d) a
and c 24. Vector data model is best for a)
Traditional cartography b) Topology c)
Continuous space d) a and b
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Review
25. Of the ArcGIS component applications
ArcCatalog, ArcMap and ArcToolbox, which
application is best used to display, edit and
query geographic data on maps ( Circle one) ? 26.
A ______________ system includes a spheroid,
datum, projection and units. 27.While working
with feature attribute tables, when fields from
one table are appended to another table it is
called a ____________(choose one join,
relate)? 28.Selecting features based on their
location is called a ___________(choose one
spatial query, attribute query). 29. What kind
of analysis would you perform if you where
looking for locations with a beautiful
view? 30.The geodatabase data model of ArcGIS 9.3
is and example of a __________-___________ data
model. 31. Network, Object-Relational and
Hierarchical data models are examples of a
___________ data model (choose one Conceptual,
or Logical ).
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Review
32. A collection of persistent data stored in a
DBMS so it can be shared and used by different
users in an organization is a____________________
______? 33. A geometric distortion of remote
sensing involving the rotation of an aircraft
that causes a wing-up or wing-down attitude is a
___________________? 34. Name two things you can
learn from a classification histogram. 35. What
are the two most important factors to consider
when choosing a map projection? 36. The rate of
change on a topographic surface (rise over run)
is _________. 37. In surveying, an_____________
uses two distances and right angle. 38. A
___________is an abstract representation of some
real thing. 39. What is Geographic Data? 40.
When would you use the vector data model versus
the raster data model? 41. To triangulate, a GPS
receiver measures distance using laser light
between Satellites and your GPS receiver.
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Exam Next Tuesday the 17th

• Look at class notes, first quiz, chapters in Lo,
  ESRI tutorial review for each lesson through
  module 4.
• Module 5 is due February 19th.

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Facts can be ignored but we cannot escape there
consequences. If the facts dont matter, this
means that the people who are going to have to
pay those consequences dont matter. Thomas
Sowell