GPS

Fall 2000

Spring 2001

What is GPS?

•Constellation of satellites

•Developed by Department of Defense

•Used 24 hrs./day anywhere on Earth

•Dead reckoning- `direction calculated by last position.

•Land-based positioning -Uses radio towers, Must have three towers

•Satellite-based positioning-AKA. Global positioning system. GPS for short.

Where on Earth are We?

Segments of GPS

•Space- Space- SatellitesSatellites

•User- User- UsUs

•Control- Control- MonitoringMonitoring stationsstations

Space

•24 satellites24 satellites•12,000 miles above Earth12,000 miles above Earth•Orbit twice dailyOrbit twice daily•Always have at least 4 Always have at least 4 satellitessatellites

““In View”In View”

• = above horizon= above horizon•Each satellite sends & Each satellite sends & receives radio signalsreceives radio signals

•Radio signals travel Radio signals travel 186,000 miles per second186,000 miles per second

•Satellites equipped with Satellites equipped with atomic clock for accuracyatomic clock for accuracy

““In View”In View”

UsesUses

•MilitaryMilitary•IndustrialIndustrial

•CommerciCommercialal•CivilianCivilian

Control location list

The orbital paths of today's GPS satellites

A scientists working on a

GPS satellite

Satellite Information

Name --> NAVSTAR

Man.-> Rockwell international

Alt. --> 10,900 Nautical miles

Lbs.. --> #1900 in orbit

Size. --> 17' with solar panels extended

Orbital R. 12 hr

Orbital P. 55° to equatorial plane

Planed life 7.5 years

# built 11 Block 1 prototype

28 Block 2 prototype

Constellation 24 satellites

triangulation

Data reception/

distribution

Cars, planes, Cars, planes, and boats use and boats use GPS to GPS to Navigate.Navigate.

Triangulation Triangulation is uses by is uses by receivers in receivers in the vehicles the vehicles to pin point to pin point position.position. Multiple users

The Pseudo-random code.

GPS systems use a complicated digital code to record information and send their signal for our receivers. The advantage is with these codes you can also make time measurements.

Satellites not only transmit a pseudo-random code for timing but also transmit a “Data Message” about there exact orbital location and their systems health

Quick plan= a scale that gives you PDOP and Nsats in order to calculate good data collecting days and times

PDOP=positional dilution of precision

Nsats= satellites numbers available

Satelev/ Satellite Level= how high there are in the sky. During the day

Any Questions

GPS Mapping of the Beaver Creek Field Research Station

Nick P. & Denver J.Fall 2000 Spring 2001

Nick P.

Computer man

Denver J.

Mapping Man

Our plan:

To create an GPS accurate map of the field station

Beaver Creek Field Research Station

400 +

acres of mapping pleasure

Some Starting Questions •What do we need to know about mapping?

•What should we Map?

•When finished how will people use our map?

•What type of data do we need gathered?

•What kind of equipment do we need?

•How long will it take? Will we be finished by the end of the year?

•What efforts shall we undertake to prepare future students interested in GPS mapping?

Some Starting Questions

How we use GPS1. Look at Quick Plan program to find when the data collection will be good.

2. Decide what we want to map.

3. Make a data dictionary for sorting our data.

4. Begin mapping area in interest.

5. When we’re done we return to school and load the data in to the computer.

6. After reviewing the data, we decide whether to remap or correct.

7. Retrieve internet correction files from http://www.ngs.noaa.gov/cgi-test/ufcors2.prl,

to differentially correct data.

8.Export to ArcView.

Problems we hadThe battery going dead when mapping, Poor data reception, Weather, School Conflicts, illnesses

Not being able to correct our data files.

Transportation problems during the winter.

Technology problems with computers

Among many others

Pathfinder Office

We use Pathfinder to analyze correct, export, and delete data. We also set up data dictionaries which it an organizer for data, form here we can load and unload data from the GPS receiver.

ArcView

In ArcView we are able to set projections placing items were they need to be, also can create good looking maps of what we are doing. Here we can set specific values for different features giving them distinction from other data layers.

Some of our field work

At the Beavercreek field research station.

• Trails/roads

•Fields

•Steam/ponds

•Corner points

•Bird feeders

Our First Generation Map of the Beaver Creek Field Research Station

Any Questions

Mapping Deer Trails with GPS by Andy Eklof and Randy Klatt

What Vegetation Types Do Deer Prefer?

Our Hypothesis:Deer Prefer Areas Dominated By Oak, Aspen, and Pine Vegetation.

Where Did We Get The Background For Our Hypothesis?

“Deer trail abundance suggested a strong preference for open, aspen, and jack pine habitats. Lower deer use occurred in oak and red pine habitats…….If the management objective is to maintain the existing deer habitat suitability in central Wisconsin, we recommend maintaining as much of the existing open, aspen, and jack pine habitats as possible.”

-Habitat Relationships of Deer and Ruffed Grouse in Central WisconsinJohn F. Kubisiak and Robert E. RolleyWisconsin Department of Natural Resources

Research Report #176, March 1998

Where And When Did We Perform Our Research?

Air photo of the Beaver Creek Field Research Station

How Did We Record The Deer Trails?

What Did We Do With Our Recorded Data?

How Did We Know What Vegetation Dominated The Area Where We Did Our Research?

What Type of Vegetation Did Deer Prefer?

What Type of Vegetation DidThe Deer Prefer The Most?

0

0.2

0.4

0.6

0.8

1

1.2

Agland Poplar-Pine White Pine Red Pine JackpineOpen

Oak-Maple DeciduousHardwood

Oak

Vegetation Type

Mile

s

Trail DistanceHighway Distance

Travel Distances by Vegetation Type

To Summarize

• “Deer trail abundance suggested a strong preference for open, aspen, and jack pine habitats. Lower deer use occurred in oak and red pine habitats…….”

• While we found that deer prefer vegetation dominated by oak and pine, they also prefer open fields surrounded by oak and pine vegetation.

Original Hypothesis Our Findings

Any Questions?