Implementing GPS Data in your DataPlus Mobile Application — Part 2: Collecting Line or Polygon Data to an External File

One of the new features in DataPlus Mobile is a GPS App tab for easily collecting spatial data with your DataPlus Mobile application. Through the GPS tab you can configure your application so that you can record latitude, longitude and elevation fields associated with your specific application.

Points can either be logged internally (as fields within the data set) or into an external file associated with the branch. If you are recording GPS data as lines or polygons, your GPS data will automatically be logged to a separate (external) file.

In this example we will configure our DataPlus Mobile Tutorial application so that we can record latitude, longitude and elevation along a line, and have these values logged to an external file associated with the DataPlus Tutorial forestry application. An example would be if you wished to record a stream or a road as a line attribute while you were collecting data within a forest plot. The same steps apply if you are collecting data for a polygon, for example if you were mapping a property boundary around the plot. Line and polygon data can be collected with one of two methods: log at interval (seconds) specifies that a point in a line or polygon is to be stored at the specified time interval, or log position at minimum distance from prior position (feet) will only log a point in the line or polygon if the prior position has varied more than the value specified with the option.

It is assumed that the user has an in-built or properly connected external GPS receiver and the manufacturers’ software to select NMEA sentences.

Enable GPS logging of a Line attribute

  1. Select Application/Open
  2. Select your application (Tutorial in our example), Click OK
  3. Select the appropriate level in the hierarchy, Plot in our example
  4. Click on the GPS icon
  5. Under the GPS tab, middle section for Lines, click Enable, and make a selection to Log at Interval (seconds) and set to 5. You can also consider the option to Log a position at a minimum distance from prior position (feet) if this meets your project needs. This window also includes options where the user can check a box for Required before level retreat so that data must be collected before the user can exit to a higher level or the option Required before moving from record where the user will not be able to move from the current record until they have completed collecting data along the line or polygon.

*Note: To log GPS data along a line or Polygon at any level you must check Enable for Lines and/or Polygons for this feature to be enabled at that level.

DPM_part2

  1. Click the Save and Compile icons at the top of the page
  2. Use DataPlus Mobile Host to load the application to your handheld/GPS/Tablet for testing.
  3. On the handheld/GPS/tablet, go to NEMA output settings and select the GGA sentence as a minimum. You should turn off any sentences that provide quality or status information.
  4. From the main screen of DataPlus Mobile on the handheld/GPS/tablet, access the GPS icon, select Port Settings, and set the appropriate port settings for your specific GPS receiver.

When you are at the main DataPlus Mobile screen, tap the GPS icon and Connect, and you will be able to see current GPS status information on the screen:

DPM_part2_2

When you are at the appropriate level within your application, Plot in our example, press CTRL G to see the following screen:

DPM_part2_3

Select Yes and DataPlus Mobile will automatically advance to this screen and start recording positions along a line at the selected interval, every 5-seconds in our example.

DPM_part2_4

When you have completed your line press CTRL G again to Stop Logging GPS line for a plot file.

In addition to your converted files which contain your field data, you will also have a separate file with the line or polygon data. This file name will include the hierarchy name followed by Line or Polygon (e.g. Plot Line in our example).

Future To the Field and Back posts will address using laser rangefinder data in your DataPlus Mobile app and the new DataPlus mobile branch control feature.

In addition to DataPlus Mobile, Electronic Data Solutions provides other field data collection software including WetCollect and Everglade for wetland delineations, FieldSeeker GIS and Sentinel GIS for vector control, custom application development in Esri Collector app and ArcGIS Online, and custom software development.

On Tuesday, September 22, 2015 join us for a free webinar giving a general overview and a look at what’s new in DataPlus Mobile. Register Here.