G338/G538
Howto document
How do
I use data I collected using a GPS to create point, line and polygon features
in ArcGIS?
Created
12/3/2003 (Tom Evans)
Updated 10/24/2006 (TE)
There are basically
three ways to get X,Y data into a dataset in ArcGIS. Use method #1 if you have a lot of points to enter and especially if you're just creating point features. Use method #2 if you're entering a few points to make a simple polygon. Use method #3 if you are using lots of separate points to make many distinct polygons or lines.
Instructions for method #1:
1. Open a new MS Excel document, in the first row enter "X" (no quotes) in the first column and "Y" (no quotes) in the 2nd column
2. Enter the X and Y coordinates for your coordinates on the subsequent rows
3. Save the file as an Excel file, then do a Save As, saving as a DBase IV format file (*.dbf extension). Small caveat, starting with ArcView version 9.2, ArcGIS will be able to open Excel files directly so you won't need to Save As DBF
4. Close MS Excel
5. Open the DBase file in ArcMap (Add Data) and then from the Tools menu select Add X,Y Data. Then select the DBase table and it should create point features. Then you'll want to Export (from File menu) that as a shapefile or feature Class, and then IMPORTANTLY, use the Define Projection tool to specify the spatial reference system of the new dataset (so ArcGIS will be able to use projection on the fly)
Instructions for Method 2:
General instructions:
Here are instructions for the ArcMap method #1. The basic steps are as follows:
- Create new Personal Geodatabase
- Create feature class in new Personal Geodatabase
- Start ArcMap, add feature class from step 2, View Editor Toolbar, Start Editing
- Manually enter X,Y coordinates for features you will create (F6 or Rt. click - Absolute X,Y)
Detailed instructions:
- Create New
Personal Geodatabase
- Start
ArcCatalog, navigate to the directory where you want to create the new
Geodatabase
- Right click
in right hand window pane and select New : Personal Geodatabase
- Double
click on the new Personal Geodatabase you just created, right click
in the right hand window pane and select New : Feature Class
- Name the
Feature class (i.e. "street" or "woods")
- Proceed
until you get to the dialog box that has the "Field Name"
and "Data Type" columns
- Click
on SHAPE
- In the
table at the bottom of the dialog box change the Geometry Type to the
type you want (Point, Line, Multipoint or Polygon)
- Click
the ellipse (the "..." at the bottom) to set the spatial reference,
then use either of these two methods to set the Coordinate System, Map
projection and Datum
- Click "Import", and then select a dataset that is in the same
coordinate system, map projection and datum as your GPS data were
collected.
- VERY
IMPORTANT: NEXT CLICK THE "X,Y DOMAIN" AND SET THE
MIN AND MAX X,Y VALUES - IF YOU FORGET TO DO THIS STEP THEN
YOU WILL PROBABLY NOT BE ABLE TO CREATE FEATURES WHERE YOU WANT
BECAUSE THE SPATIAL EXTENT OF YOUR FEATURE CLASS IS IN A DIFFERENT
COORDINATE SPACE THAN WHAT YOU WANT
- Alternatively,
click "Select" and set the Spatial Reference information
manually
- Click "OK" to close the Spatial Reference dialog box and "Finish"
to close the "New Feature Class" dialog box and create the
empty feature class
- Start ArcMap,
add feature class from step 2, View Editor Toolbar, Start Editing
- Enter an edit
session in ArcMap, choose the Sketch Tool (pencil icon on Editor menu).
Press the "F6" key and enter the X,Y coordinate for point or vertex.
Alternatively you can right-click in the Data Frame window which will bring
up the same dialog box as pressing "F6".
- Continue until
you've added all the features or points. From this point on it is the same
as heads-up digitizing...
Common mistakes
(if you encounter problems):
- Not setting
the Geometry type when creating the new Feature Class
- Not setting
the X,Y Domain when creating the new Feature Class
- Not setting
the correct Spatial Reference information.
Method 3: There is a legacy method that will enable you to create polygon features automatically from a text format file - the Generate Tool available in ArcInfo Workstation (from ArcToolbox - Coverage Tools : Conversion : To Coverage : Generate). If you are interested in the Generate Tool usage follow this link.