Mapping GPS Coordinates

GEOG 3530/8535 Cartography & GIS

University of Nebraska at Omaha

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 2007 table. Then you will bring the Access table into Arcmap, label the points and create a map in PDF format to post on your web page.

Database

A database is a collection of information organized in such a way that a computer program can quickly select desired pieces of data. Databases are typically organized into tables, which are collections of related items. You can think of a table as a grid of columns and rows. A column defines one piece of data stored in all rows of the table. A row contains one item from each column in the table.

For example, a table might contain the ID, name, title, and other information for individuals employed by a company. Each row, called a data record, corresponds to one employee. The value of a column within a record is referred to as a record field.

MS Access 2007

Access 2007 Getting Started screen includes a variety of pre-built databases solutions that you can use to track contacts, events, issues, assets, and tasks. Access 2007 makes it easiy to work directly within a datasheet to create and customize tables. Information is entered into a data cell – just as you would do in Excel – and if it’s a new value, Access 2007 automatically adds a new field and detects the data type (for example, data, number, or text).

For more Information also see

· Microsoft Office Training: Get to know Access

· http://inpics.net

· http://techtutor.tv

· http://www.access-freak.com

Assignment

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. Right click on Layers > Add Data. Browse to S:\Peterson and choose Douglas_color.sid and click on Add. Go to UNO and Zoom In. Now open 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 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 2007.

4) Open Microsoft Access which is under Start > Programs > Microsoft Office > Microsoft Access 2007 (if you want to work with Access at home, you need to have MS Office 2007 or you have to save your Access Database as Access 2002 – 2003 Database that will be compatible with Access 2002-2003).

5) You see the new Getting Started screen of Access 2007. Click More below Open Recent Database > Browse to your UNOlocations Database and open it. When the security warning pops up, click Options > OK.

This brings up a Table of Contents which lets you work and organize your files in Access.

6) We are going to work with tables in our assignment. On the left side you will get all the tables which are available. There already are some tables which are default tables for use with ArcMap. The table you created in the ArcCatalog should be displayed on the last table. Double Click on UNOGPS : Table and it will open.

There are two different views of a table, the Design View and the Datasheet View. Choose View > Design View (the left upper corner below the new Office 2007 sign). 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 will have 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' is 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.

name	latitude	longitude	latitude in decimals	longitude in decimals
bell tower	41˚ 15.493' N	96˚ 0.628' W	41.25822 (you have to divide 15.493 and add them to the 41)	-96.01047 (you have to divide 0.628 by 60 and add it to 96)
Arts & Sciences	41˚ 15.484' N	96˚ 0.356' W	...	...
bus stop	41˚ 15.433' N	96˚ 0.632' W	...	...
Durham	41˚ 15.500' N	96˚ 0.773' W	...	...
Football field	41˚ 15.477' N	96˚ 0.475' W	...	...
UNO Foundation	41˚ 15.538' N	96˚ 0.931' W	...	...
pillars	41˚ 15.503' N	96˚ 0.824' W	...	...
student center	41˚ 15.498' N	96˚ 0.480' W	...	...

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 back to ArcMap > 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 correct 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 scalebar, and a north arrow. Inserting these objects can be done via the Insert menu. Remember to include a scale bar.

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 grading.

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