Mapping GPS Coordinates

In this assignment we will map the coordinates we measured with the GPS units. To do this, you will first put the coordinates in an MS Access table. Then you will bring the Access table into Arcmap, label the points and create a pdf map.

Creating a table in Access

Microsoft Access is a database which lets you enter, retrieve, sort, analyze, and summarize data, and report results. A database is much more than just a list or table, like an Excel file. With a database you can combine data from various files, so that you never have to enter information twice. A database can make data entry more efficient and accurate. It is mainly used to manage sales and inventory numbers. This can be student records for school, employees data, or perhaps your home collection of DVDs, CDs, and videotapes.

Access creates relational databases, which means that data is stored in various separate tables by subject or task, but the data is related and can be brought together in ways that you specify.

For more Information also see Microsoft Office Training: Get to know Access

Let's start with the assignment. You will first create a personal geodatabase in the ArcCatalog and create a database table.

1) Open ArcMap which is under Start > Programs > ArcGIS > ArcMap. Open a new empty map. Now open the ArcCatalog by choosing Tools > ArcCatalog.
This brings up the ArcCatalog which has the same structure as the Windows Explorer, but lets you store and manage your geographic data.

2) In the ArcCatalog browse to a location of your choice (e.g. My Documents) and create a new geodatabase by right-clicking in the right window and choosing New > Personal Geodatabase. Give it a reasonable name like UNOlocations.mdb etc.

3) Double click on your new geodatabase and right-click and choose New > Table. Give it a name (e.g. UNOGPS), click next, make sure default is checked, click Next and hit OK. This creates a table which you can now open in MS Access.

4) Open Microsoft Access which is under Start > Programs > Microsoft Office > Microsoft Access (if you want to work with Access at home, you need to have MS Office Professional).

5) Choose File > Open, browse to your UNOGPS.mdb table and open it. When the Security Warning pops up click Open.
This brings up a Table of Contents which lets you work and organize your files in Access. Access consists of Objects which you can see on the left side. They are Tables, Queries, Forms, and Reports.

Tables store your data in rows and columns. All databases contain one or more tables. Queries retrieve and process your data. They can combine data from different tables, update your data, and perform calculations on your data. Forms control data entry and data views. They provide visual cues that make data easier to work with. Reports summarize and print your data. They turn the data in your tables and queries into documents for communicating ideas.

We are going to work with tables in our assignment. When you click on Tables under the Objects menu you will get all the tables which are available. There already are some tables which are default for the use with ArcMap. The table you created in the ArcCatalog should be displayed on the last table. When you double click on it it will open.

There are two different views of a table, the Design View and the Datasheet View. Choose View > Design View. This is where the database designer (you) create the different columns of the table and their attributes. Your table already has a column called OBJECTID. This automatically assigns an individual number to each row with data you are going to create. Now, under Field Name create three more columns called name, latitude and longitude. Assign the Data Type Text  to your name field, and both the latitude and longitude fields the data type Number. The available data types are accessible under a drop down menu when you click in the data type field next to the respective field name. In order to be able to enter decimals, you need to change the field size in the general tab at the bottom to Single.

Now go back to the Datasheet View (View > Datasheet View) and click Yes to the prompt to save your table.

You now should have an empty table with the data fields you just created in the Design View. Our next step will be to enter the data we measured with the GPS units.

Go ahead and put a name and the latitude and longitude for each of the measured coordinates in your table. Make sure you put in the decimal number in Access. You also have to put a minus in front of each longitude because we are located west of Greenwich.

To get from degrees, minutes and seconds to the decimal, you have to divide the minutes by 60. For example 96˚ 0.926', the longitude for the alumni building. You have to divide .926 by 60 to get .01543. This makes a decimal longitude of 96.01543.

Because all our points are relatively close together, you should at least use five decimals for the assignment.
 

When you have entered your GPS coordinates you can close Access.

Mapping the UNO locations in ArcMap

Now we are going to map out these coordinates on a new map we created as we opened ArcMap.

Go to Tools > Add XY Data. Click on the folder icon next to the empty box and browse for your UNOGPS table. Click Add.

In the two drop down menus underneath you can choose your two columns of the data table which have the GPS coordinates. The x-coordinate is the longitude and the y-coordinate is the latitude. Since we have named our fields latitude and longitude, it already selects the right columns by default.

Click Edit to select a Coordinate System. Click Select to use a predefined coordinate system. Choose a Geographic Coordinate System for North America like the North American Datum 1983.prj. Hit OK to apply the coordinate system. When you hit OK again your locations are going to be displayed on the map.

To analyze whether the coordinates are right we need to label the points. We typed in the name of each point in our Access table earlier. To display the name, right click on the Layer in the Table of Contents and check Label Features.

We are now create a pdf map which you can submit to your Webfolder. Change to the Layout View (View > Layout View). Right-click on the page and choose Page and Print Setup. Choose Landscape. Also insert a title, your name with a textbox, a neatline, a scalebar, and a north arrow. Inserting these objects can be done via the Insert menu.

To make a pdf of your map, go to File > Export Map. Make sure that the file type is pdf and save the file in your folder you already used for this assignment. Submit the pdf file to your Webfolder for the grading.

Before closing ArcMap, save your whole ArcMap project under File > Save As as an mxd file.

Lab created by Eva Grund, Fall 2004.