project 2: locating geographic coordinates with gps presented by: kurt ehrenfeuchter, sally ho, and...

Project 2: Locating Geographic Coordinates with GPS

Presented By: Kurt Ehrenfeuchter, Sally Ho, and Justin Hoy

GPS (Global Positioning System)

GPS is a system to calculate a

position or coordinate on the Earth’s

surface. GPS consists of a “space”

component and a “user” component.

The “space” component refers to

numerous satellite’s that are

constantly orbiting the earth sending

coded signals. The “user” component

refers to receivers that decode

satellite signals and use them to

process information (such a distances

from the satellite/s).


GPS uses the process of triangulation

to approximate the location of where

a “user” is receiving a signal on the

Earth’s surface. As seen in

class, the greater the distance

between satellite’s, the more

approximate the GPS reading will be.

In conjunction with this, the more

satellite’s used, the more precise the

GPS reading will be.


Although GPS systems are excellent examples of how

Technologically advanced we have all become, it does have its down

falls that we must be aware of and consider while using GPS software.

The first problem with GPS is atmospheric delay. The coded signal

being sent by the satellite must travel tremendous distances and

“bounces” off things when coming through the ionosphere and

troposphere. This increases the time it takes to be received and

decreases the accuracy of the GPS reading.


The second problem involves a term known as multipath. Ideally, the

signal would come to the receiver in a straight line (thus taking the least

amount of time), however, due to reflections in the atmosphere and on

the ground the signal can be redirected before reaching the receiver.

This interrupts the signal increasing the time it takes to reach the user,

as well as decreases the accuracy of the GPS.

The third problem is obstruction. This is pretty self explanatory in

that sometimes features on the landscape interrupt the ability for

signals to be received by GPS instruments. Things such as forests,

cities, and steep mountains are all example of obstruction.


Now that we have reviewed

the basics of GPS we can get

ready to talk about Project 2!

However, keep in mind the kinds

of things that can interfere with the

accuracy of a GPS reading, you may

find that you experience some of

these inaccuracies when your

conducting your work!

Project 2: Locating Geographic Point with GPS

Project 2 is divided into two different parts:

The first part of the project is referred to as 2a. In this section you

will work in groups of 3 to 4 people (no flying solo on this one!), and you

will locate two different locations on campus by using a GPS handheld

receiver. This will acquaint you with how to read the data on the GPS

and get use to using its various settings.

So really, your going on a GPS scavenger hunt!!


Part 2a Continued…

Once you feel comfortable with the GPS and have located your twolocations on campus, you can move onto the second part of 2a. Nowyou get to learn how to record certain locations within the GPS device.These are called waypoints, by following a simple process that we willdiscuss in a few slides, you can record points into your GPS for lateruse. For this part of the project, you and your group must travel aroundcampus and record 4 different locations (make sure they are far enough apart so they can be visible on a map) as waypoints. Makesure every member records a location, and these locations can rangefrom historical landmarks around Penn State to the place you drankyour first beer, don’t be afraid to be creative!



Before you embark on part 2a of this project your going to need

some supplies. One member of your group is going to need to sign out

a GPS handheld receiver from your TA (that’s Missy!). In addition to

this, you’ll need to acquire a copy of the handout prepared by Missy,

telling you the latitude’s and longitude’s of your locations on campus to

find using your new GPS receivers.



Your GPS receiver is a Garmin

GPS 12 Personal Navigator, which

comes in a carrying case and a copy

of the owner’s manual for the unit. I

would strongly recommend reading

pages 5-11 of the owner’s manual

before turning on the GPS unit to get

familiar with how it works and to save

batteries. Although we will go through

some of the basic features of the

GPS receivers.


Using the GPS receivers:

The first step to using any electronic device is to turn it on! The

power button for the unit is located on the left hand-side above the

screen between the “GOTO” and “QUIT” buttons (it has a red light bulb

on it). Once the GPS receiver is powered up it will take you to the first

of 5 possible screens, the first being the Satellite Page. Your most likely

going to have to wait a few minutes for the receiver to communicate

with the satellite/s (our first experience with atmospheric delay) and

show you which one’s it can establish a connection with.



Once you are connected with the satellite/s push the “PAGE” button

located on the upper right. This takes you to the Position Page. This

page gives you valuable information such as your position (i.e. latitude

and longitude) as well as your elevation, heading, time, and even

speed at which you are traveling. This is the screen you will primarily

use for the first part of 2a (locating your two mystery points).



Now since we are a nice leadership team and don’t want you running around aimlessly looking for your points we are going to save you some confusion that we bumped into when we started searching. If you look at your Position Page on your GPS you’ll see that the lat. and long. are recorded in degrees, minutes, and seconds. This normally isn’t a problem except that on your worksheet your lat. and long. are in decimal degree format. An easy fix to this problem is to go to the website:

http://www.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html

and type in your coordinates. (Your welcome!)



Now that you have coordinates in

the same format as your GPS

receiver you can begin to locate your

two mystery locations. Be sure to

bring your owner’s manual and extra

batteries incase you run into any

problems along the way. You will also

need your worksheet to document

where your coordinates take you!



As discussed earlier, this part of the project involves recording 4different locations around campus (be sure they are far enough apartthat they can be easily viewed on a map). These can be anywhere onthe campus map provided (i.e. between Walker and the HUB) and they canbe your houses, where you work, historical sites, or even where youdrank your first beer, etc. Each member of your group should recordone point in the GPS receiver.

Recording points in the GPS receiver is an easy process that we willillustrate now for you….



Once you get to the location that you wish to record onto your GPS, push

the “MARK” button (the middle right button) and it will take you to a new screen

that says waypoint at the top. At this screen you should see the latitude and

longitude of the point you want to store, this means that the GPS has

recognized your location, but before you move on make sure you save the

point by highlighting the “save” option on the lower right and hitting “ENTER”.

You need to get 4 waypoints and each member of your group should have a

turn to record a point. (Before you actually begin this process it might be a good

idea to go into the waypoint screen and delete any previously marked

waypoints to save time later!)


Project 2b:

Now that you have found the two mystery points and have plotted your own

4 locations, it’s time to move on to the last part of the project. Your group will

have to go to the Walker Building computer lab (room 208), and get a special

cord to connect your computer to the GPS. Once you are connected you will

have to download your data using the waypoint software, format it correctly in

Microsoft Excel, and then use Excel to import and plot your points onto a map

in Arc View. This portion of the project is fairly detailed, so if you would like to

follow along with the description of this section o the project you may do so by

going to:

http://www.geog.psu.edu/courses/geog121/projects/proj2b.html


Project 2b continued….

Step 1 is to hook your GPS up to the computer via a special cable providedin Walker building. Once connected you must open up the waypoints programlocated under the Geog121 tab found in the START menu.

Step 2: Once the program is up and running you have to download yourwaypoint from the GPS onto the computer. To do this, just simply go to the“GPS” tab, select the “download from GPS” from the pull down menu, and fromthere select “waypoints.

Step 3: Once your waypoints are highlighted go to File and select“configuration”, in “configuration” change your settings to Decimal Degrees andStatute Miles (this is the default settings for the program, they must be in thissequence because the datum you will have to use is measured in feet and anyother setting will distort your map).


Project 2b continued….

Step 4: Next you have to select what

datum you are going to want to use, to do

so you must go to File and on the pull

down tab select “Datum”. This project

requires that you use the “WGS84” datum

located towards the bottom of the list,

because this datum corresponds to the

map you will need to plot your waypoints

on.

Step 5: Is to simply save your

progress thus far, to do so go to File on

the pull down tab select “Save” and then

“waypoint”.


Project 2b continued…

Step 6: You will now need to open your newly saved waypoint file into Microsoft

Excel. To do so, open Microsoft Excel, select File and “open”, make sure the file type

menu is set to either “text file” or “all files” otherwise you will not be able to view your file.

When you do this you will be prompted by a pop-up screen to “delimit” your data, just

simply follow the onscreen instructions to NOT delimit your information.



Step 7: Once you have followed all of the “delimiting” instructions your

information will open in Excel. Your latitude and longitude for your various

points will be listed, along with extra information such as the date, time, etc.

You only need the information listed under tabs C, D, and E (latitude, longitude,

and waypoint number). After you delete all the other information except the

required fields, you can rename them as “waypoint”, “latitude”, and “longitude”.

We will demonstrate this for you on the next slide.



Step 8: Once you have formatted your file, you must save it. Be sure you

save your file as a text file (.txt) because you can’t use Excel files in Arc

View.

Step 9: Next you will have to go to angel and download the zipped Penn

State Campus map. This file is listed on angel as “Project 2b: Campus Map

Data” and follow the instructions given on angel for properly downloading the

file.

Step 10: Once you have downloaded and unzipped the Map file open Arc

View and select a new map. To import the Penn State map form angel, you

need to select he button located to the left of the scale (it looks like a yellow

street sign with a plus sign on it). You will need to load each layer (i.e. mask,

roads, etc) individually. Make sure you load the mask layer first, followed by

the others.



Step 11: After you have loaded all the layers and can view the map, you have to verify your coordinate system. To do so, right-click on the layers page (left side) and select “Data Frame Properties”, when this opens go to the “coordinates” tab and make sure your coordinate system is set to the “NAD_1983_State Plane_Pennsylvania_North…..”. You must use this coordinate system because it is currently the most up to date system in this program.



Step 12: The next step involves loading your GPS waypoints onto your

newly created map in Arc View. To do this, go to the “Tools” tab, select

“Add XY Data” from the pull down menu, and a new screen will appear showing

you the settings for your data. At this point you should put in your table from

excel. From here you need to tell ArcMap what Datum you are going to use, so

where it says “Spatial Reference of Input Coordinates” find the edit button and

it should take you to another menu. From this menu go to select, that will then

take you to the folder with coordinates systems in it. There are a lot of different

choices in here but the one we are looking for is WGS 1984. So you want to go

to the “Geographic Coordinate Systems” then choose the “World” folder, and in

the World folder you should see the WGS 1984.prj Datum. (last one in the list)



Step 13: Once you have verified your data, hit ok and upon doing so a new layer called “waypoints” will appear under your layers listing. This will display your waypoints on the map!

Step 14: The final step just involves saving your map as a screen capture so you can load it onto your webpage at a later date. To do this, just locate your “Prnt Scrn” button, it may be located in the upper right, or as a function key depending on what kind of computer you are using. While in the screen you want to save, simply press “Prnt Scrn”, then go to whatever you are going to save the image to and paste it.

Congratulations! Your almost there!


Project 2:

Now that you have successfully made your map consisting of your GPS

points, you can go on to the final stage of the project. If you would like to see

an example of how your finished project should look like, you may do so at the

following webpage:

http://www.geog.psu.edu/courses/geog121/projects/proj2b_example.html

The final copy of Project 2 requires your name, the image of the screen capture

you saved, followed by a description of the points you plotted, experiences, and

the equipment used. This will then need to be uploaded onto your personal

webpage and hyperlinked under “Project 2”.


References:

Baxter, Ryan. Lectures 6 & 7 – GPS. Class notes for Geog 121, Penn State

University, 2006.

Degrees, Minutes, Seconds and Decimal Degrees Latitude/Longitude

Conversions. http://www.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html.

Accessed 6 October 2006.

Geography 121 Project 2b (Example) .http://www.geog.psu.edu/courses/

geog121/projects/proj2b_example.html. Accessed 6 October 2006.

Geography 121 Project 2b. http://www.geog.psu.edu/courses/

geog121/projects/proj2b.html. Accessed 6 October 2006.

http://www.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html


Contact Page:

Kurt Ehrenfeuchter, [email protected], cell (717)-571-5168

Sally Ho, [email protected]

Jason Hoy, [email protected], cell (814)-883-6737

http://www.personal.psu.edu/jeh5003

project 2: locating geographic coordinates with gps presented by: kurt ehrenfeuchter, sally ho, and...

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