Global Positioning Systems (GPS) An Overview of Pathfinder Office & Trimble Juno

Transcription

1 Global Positioning Systems (GPS) An Overview of Pathfinder Office & Trimble Juno Introduction PCC would like to provide campus maps to current and prospective students, as well as visitors to the campus that highlights campus landmarks / points of interest. As a GIS student, you will go around and collect data on the following sites (and any additional sites, per your interest) along with some data about the sites: Watershed Mural Track Windmill Learning garden Rain garden (by the track) Salmon Bench Worm Bin Straw Bale House Good Neighbor Zone(s) Main Bus Stop The information you want to include about these sites (attributes): Category (art, sustainability, athletics, services, other) Location (Outdoor / Indoor) Another attribute of your choice Part I. Creating a data dictionary in Pathfinder Office Here is a link to a video I found a video on creating Data Dictionaries in Pathfinder Office. This may be helpful ( What is a data dictionary? A data dictionary is a custom made database for your data collection. It simplifies data collection and stores the collected data in a form that is useful for your specific mapping/ analysis needs. Before you create a data dictionary you need to consider what kind of data you are going to collect. You first create a data dictionary in Pathfinder Office and then transfer it to your GPS receiver (in your case, the Trimble Juno). As you collect data it will be stored in the data dictionary database on your GPS receiver for later export to ArcGIS. Open GPS Pathfinder Office and start a New Project, naming it Sylvania and set up a directory on your flashdrive (use the browse buttons to save the project on your flashdrive). Go to Utilities > Data Dictionary Editor to begin creating a data dictionary 1

2 Add a name to the data dictionary, Sylvania, and save it to your flashdrive. Add a new feature to your data dictionary. For the purposes of this exercise, you will only have one feature type Points of interest that will be points. Click on New Feature in the Data Dictionary Editor. Set the following parameters for your new feature: o Feature name: Points of Interest o Classification: Point o Minimum Positions: 4 o Symbol: This will be what appears on the map in the GPS unit, you can change this if you prefer o Keep all other settings at the default Click OK when you are finished Next, you will set the Attributes for your Points of Interest features. Make sure Points of Interest is selected in the Data Dictionary Editor and click on New Attribute. 2

3 The first attribute you will create is for the Type and this is going to be a Menu attribute, meaning that you will have a menu of options to choose from. Select Menu. Name the attribute, Type, and add the following menu option: Art, Sustainability, Athletics, Services, Other. Make Sustainability the default option. Check to make sure your New Menu Attribute looks like the screenshot below, and click OK. Create two more attributes: Location and one of your choice. Save the data dictionary when you are finished and close the window. 3

4 Part II. Transfer the Data Dictionary to GPS Make sure the GPS unit is charged and turn on the Trimble Juno GPS receiver. Use the Stylus Holder to click on the Windows icon on the bottom left of the screen. Scroll down and click on TerraSync (professional edition). Connect the Juno to the computer using the USB port. Open Pathfinder Office (if not already open) and go to Utilities>Data Transfer When the Data transfer window opens, click on the Send tab and go to Add and select data dictionary (see screen shot below). 4

5 When the window pops up, navigate to wherever you stored your Sylvania.ddt, and click Open. When you return to the Data transfer window click on the Transfer All button. To check to make sure it was uploaded correctly, go to the TerraSync program on the Juno. You should see a screen similar to the image below. Select Data from the Section button and then File Manager from the subsection button. 5

6 Once you are in the File Manager, go to Choose File Type and select Dictionaries. You should see the Sylvania Dictionary in the list. Add the data dictionary to you Juno unit. Now, you are ready to go into the field for data collection! Part III. Collect the data The first thing you need to do is create a new data file for your data collection. Using the screenshot above (TerraSync), select Data from the Section button, and New from the Subsection button. This will create a new data file to store you data from the field. Give the file a name (Sylvania Pts) and choose the Sylvania Dictionary Click Create. Set the Antenna Height to the height above the ground that the GPS unit will be held (3.6 ft is a good estimate) and click OK. A screen will appear that shows your Points of Interest, as well as generic Points, Line, or Polygons. Each time you get to a place to collect a point, select Points of Interest, fill in the attributes from the dictionary, and click Done. Part IV. Post-processing the data (Differential Correction) Differential Correction is a way of correcting GPS data post-data collection. Essentially, the process uses a base GPS receiver that logs a position at a known location and the GPS receiver that collects data in the field. The file from the base GPS and the receiver are compared through Pathfinder Office software and the field data is corrected. There is a more detailed definition and illustrations here: Make sure your Juno unit is connected to the computer via USB. In Pathfinder Office, go to Utilities>Data Transfer. This time you will be transferring the data file you created during your data collection into your project folder. Make sure you are on the Receive tab and click Add. Find your data file from the Juno unit and click Transfer all. In Pathfinder Office, go to Utilities>Differential Correction. 6

7 Click on the plus sign to browse files and click on the Juno unit on the left hand side menu. It should automatically bring up the.ssf file you transferred from the Juno unit. Click Next. Click Next two more times, accepting the defaults in the wizard (Processing type & Correct settings). You will have to select a Base Provider. Click on Select and all the closest base stations to where you collected data will appear. Select the closest one (for Sylvania it should be USFS/BLM Portland). Select a reference position as well (should be the same as the base provider). Click Next. The next step has options for what to name the corrected file and where to save it choose your options based on your preferences. Click Start. Watch this process, you may have to confirm some options. The final screen will provide a summary of the accuracies of your points (see screenshot below). Click Close. 7

8 Part V. Convert data to a Shapefile When you collect data using a GPS, it is not in a GIS-ready format. The final step before being able to map your Points of Interest is to convert your dataset into a shapefile. In Pathfinder Office, go to Utilities>Export. The newly corrected file should appear in the wizard. If not, click on Browse and navigate to where the file is saved. Designate a place for the file to be exported. Under Choose an export setup go to the dropdown menu and select a shapefile. Notice that it tells you what the Coordinate System is for the file (WGS_84). Make sure your screen looks similar the one below (with a variation in the output location and the file name) and click OK. 8

9 A warning pop-up window will appear that looks like this: This is informing you that the exported file will not have a.prj file. This means when you bring it into ArcMap, you will have to use the DEFINE PROJECTION tool to define the projection to WGS84 (Geographic Coordinate System). Part VI. Create a Sylvania campus map Use your newly created shapefile, RLIS datasets, or any other datasets of your choice to create a map of PCC - Sylvania Points of Interest. Export your map as a.pdf and to the Instructor (lastname_sylvaniagps.pdf) 9