GIS 1 Lab 3: GPS Mapping

Tanner Borgen

Introduction

-The goal for this lab is to become familiar with creating a geodatabase, how to collect feature data points with a GPS, and adding those features to our geodatabase map.  

-The objectives of this lab were to create a geodatabase and to prepare that geodatabase for the use of the Trimble Juno GPS unit.  Then to load the geodatabase onto our Trimble unit and become familar on how to use a Trimble Juno GPS by collecting features as points, lines, and polygons.  Then Collecting these points using Arc Pad on the GPS and placing the data back into ArcGIS to complete our map. 

Methods



-The first step in the lab was to create new geodatabase then followed by adding feature classes named lines, polygons, and points.  The coordinate system used for this map is NAD83_HARN_Wisconsin_TM.  Then a raster of the University of Wisconsin Eau-Claire was added to the geodatabase.  This campus image is out of date and doesn't properly reflect the features in the map.  All of these features including the raster is added to ArcMap to create a map.

-The next step was to add this map into our Trimble GPS unit.  First from the customize menu then extensions and checking ArcPad Data Manager so this tool can be used.  Adding the ArcPad Data Manager Toolbar to ArcMap is next.  The first button on the ArcPad toolbar was clicked then from the Action Menu choosing an AXF layer and enabling editing.  In the Action Menu again, I choose Checkout all Geodatabase layers and copy out all other layers.  Then a folder with this data was created and put into my folder, then in the deployment options window I clicked on create the ArcPad data and it was created so we can use this map on our GPS device. 

-Adding the data to the Juno GPS unit is the next step.  Connecting the unit to the computer and navigating our folder that we just created to our new Juno folder is how this task was completed. 

-Then I became familiar on how to map GPS features onto my correct map.  Practicing collecting polygons, lines, and points around UWEC's campus mall was very important.  Also practicing on how I want to collect my data withe either point averaging or point streaming.  You can use point averaging and point streaming when mapping a line or polygon feature.  Point averaging takes the average vertex that the satellites read and creating the average location.  Using this method you must click add vertex on your unit each time you change direction.  When using point streaming the satellites describe your location by using an interval.  Clicking a new vertex point will not be necessary only the green arrow when finishing the feature.  When collecting point features the GPS uses the average vertexes collected in one location, in this case I used the average of 10.

-Then using the GPS unit I collected data of point, line, and polygon features.  I collected one line feature of the campus footbridge using the point averaging technique.  I then collected 3 trees and 3 light poles on campus by using the point feature class.  Finally I collected 6 different polygons around sidewalks by using the polygon feature.  3 used the point averaging method and 3 using the point streaming method. 

This is a close up of my map.  You can see some major errors while
I was using the GPS device.  

-After collecting all of your data adding it ArcMap is next.  I reconnected the Juno the computer and used the ArcPad Data Manager toolbar. Clicking the 4th button on the toolbar will bring you to a screen where I clicked the green arrow to add data.  Checking each box with my feature classes and importing them to the map.  The data I collected then appeared neatly on my map making it ready for me to create a map with clean legends and text. 

Results

-The results of my map can be seen below.  You can tell that the image we used is out of date and does not entirely match up with our new campus, as it went under major construction in 2012.  I choose to use point averaging when collecting points on my line feature class and found it to be successful.  If you look closely you can tell that some of my polygons are not accurate and jump out at some corners.  Next time when I GPS I will be more careful when collecting data so this doesn not happen.  It was tough to collect clean data with all the people on the paths I was trying to map.  





Sources: Data Collected by Tanner Borgen
Aerial photo: NAIP 201X