GPS Survey Storing Polygons
This article will show you how to start a new Acres Project and how to add areas and lengths. Acres makes collecting, measuring, sharing and storing area and length information easy, accurate and efficient. So let’s get started.
In this survey we will collect the blocks from a small town in Kentucky. The blocks are defined by streets and alleys. Although this is probably not your typical job it is something everyone can relate to and is shows the features of Acres GIS collection.
Step 1. Create New Project
When Acres opens a New Project dialog is presented. By default the name will be Prj-Month-Date in this format PrjMMDD. You can change the project name or accept the default. If you want to open an existing project change the name of the existing project. We will rename the the file for this example to Augusta, the small town we are surviving.
Step 2. Collect first Polygon
Click the big plus sign on the lower right corner of Acres map screen. You can’t miss it. The button will rotate and two buttons will appear for Areas and Lengths. Click on the areas button on the top. When the area button is clicked an “Area Mode” toast will appear and 3 new buttons will be displayed.
Point Entry Mode Buttons
- Record. Stores a new point at the current GPS position.
- Black Stop. Records a point at the current GPS position and closes the polygon.
- Red Stop. Stops recording closes polygon without adding a new point.
Step 3 Record the Points
Start by walking to the first point, a blue dot will show you your current position on the map. In the control panel at the top Acres will show you the current GPS accuracy. To collect the point click the Record button, for the first point a green start flag will appear.
Now move to the next point and repeat. This will place a red survey flag. Note that the green flag has now changed to a small green circle marker. Now move to the last point a click the Black Stop button. This will add a point and close the polygon. The polygon will now be filled and closed. A green marker will show the start of the polygon and a checked flag will mark the closing point.
Step 4 Turn on SNAP
Snap will be your new best friend with data collection. This feature works like SNAP in CAD, when you are within the SNAP limit of a marker a special popup marker will be displayed indicating which marker a point will SNAP to. To activate SNAP click the SNAP Action bar button or select from Setting in the drop down menu. Toggle SNAP on and set a SNAP distance. Start a new area when the SNAP pop-up indicates you are near your last point click on the Record Button.
Step 5 Use Touch Mode to close the Polygon
With Acres never visit the same point twice. If the point is a corner or boundary for a polygon and it has been surveyed before use touch mode with SNAP to add it to your polygon. To use touch mode long click on the map screen at the desired position. Since SNAP works with touch mode corners and boundaries match precisely. To close an area in touch mode click the Red Stop Button.
Step 6 Repeat
Collect the remaining blocks with the above methods. Remember to use SNAP with Touch mode and never visit the same point twice. Now that survey is done you have a permanent record. You can export to KML and view in Google Earth or other KML viewers. KML format can also be imported into ArcGIS or other GIS programs. You can review the Areas and Markers with Area manager and Marker Managers.
Download the Augusta KML
The Augusta KML is available for download at this link.
Augusta KML download