Adding GPS data to ArcView
If you're lucky, your Global Positioning Satellite (GPS) receiver came with a
data cable that allows you to directly export ArcView coverages from your unit
to your computer. Most likely, however, that is not the case and you'll
need to manually import your waypoints to ArcView.
- It is advisable to make sure that your unit is setup to record location
data in the same geographic projection and datum that you will be using.
If you're not sure what projection your unit is set for, chances are it is
Geographic projection, WGS84 datum, and Degree Decimal units. To
demonstrate how various coordinates look, here is the location for the GC&SU
Bobcat on front campus in some different geographic coordinates:
| Coordinate System |
X value (Long.) |
Y value (Lat) |
| Geographic Degrees Decimal, WGS 84 |
-83.230797 |
33.082269 |
| Geographic Degrees Minutes Seconds, WGS 84 |
83° 13' 50.87" W |
33° 04' 56.17" N |
| Universal Transverse Mercator zone 17 North,
WGS84 |
291804.0 |
3662515.0 |
| Universal Transverse Mercator zone 17 North,
NAD27 |
291799.5 |
3662323.7 |
| Georgia Lambert, NAD83 |
82522.3 |
12656377.9 |
- Load your location data into Excel or some other spreadsheet.
Have one column above the data with column headings (ID, X, Y). Remember
that longitude (E-W) is an X value, and latitude (N-S) is a Y value. You
can have other columns with attribute data if you like. ArcView will
read it also.
- If you entered your data as Degree Minute Second (DMS), you need to
convert it to Degree Decimal (DD) using the formula below. Remember that
negative values are given longitude West and latitude South.
DD value = Degrees + Minutes/60 + Seconds/3600
- Format the columns appropriately, especially if you're
using DD, which should be formated as Number with at least 6 decimal places.
- Select the data you want to keep. You have to SELECT the data
you want to export.
- File/Save As... the worksheet as either a DBF (dBASE IV) or TXT
(Text Tab Delimited) format. You may want to save the worksheet in both
formats in case one or the other doesn't work. Excel will fuss at you
for wanting to save data in a non-Microsoft file system; read each dialog box
carefully to make sure that you are saving the selected part of the worksheet
as a .dbf or .txt file.
- In ArcView, select the Tables icon in the Project Manager window, and
click Add. Browse to open the .dbf or .txt file you just saved.
If the file doesn't open properly, there was some kind of problem with saving
it in Excel. This can be a real pain, but you can work through it.
View the file in Wordpad or Notebook for ideas on what went wrong. Be
sure to have a column heading for each column, with tabs between each column
entry.
- In a View, View/Add Event Theme will read the contents of the table
in as geographic data. It will automatically select the columns for ID,
X, and Y values; change them if necessary.
- Once the points are properly displayed, you should select the Event Theme
in the View table of contents and Theme/Convert to Shapefile to save it
as a shapefile. If you need to,
Reproject it to the projection you're working in.