Android App

Hey Everyone,

I’ve been playing around with an Android App for basic Survey Functionality - ie: WGS84 -> UTM, Point Storage and Point Stake-out. I’ve named it the same as the other application I made, StretchRTK.

It’s fairly simple to use after you install the APK. I’ve listed a link below for downloading.

The application runs on Bluetooth, so your first step will be pairing your android device with your rover. Next you’ll have to configure solution output in ReachView; set it so the rover is outputting NEMA over Bluetooth. After that is completed you can open the StrechRTK App. On your first run you’ll be notified that no configuration file was created and that you need to go to the settings and configure before connecting to the reach.

As you can see you need to add a Proj4 string to transform the coordinates from WGS84 to UTM. I’m using the GRS80 Ellipsoid here in Canada. If you need help finding the string for the coordinate system you’re trying to use feel free to contact me.

Ignore the settings file option for the time being - Eventually it will be made entirely of Job Files containing everything. Enter the filename of the points file you wish to store in.

All of these files will appear on the root directory of your android device. I figured this would be the easiest place to place them and also the quickest place to retrieve any data after you’ve completed your survey.

The last setting is to choose your Reach from the list of Bluetooth devices. After you have completed this you should be safe to hit save and go back to the main interface.

After you have arrived at the main interface simply slide the slider over in the top right hand corner. It should connect to the Reach and quickly display the received data.

It is important to note that your current quality will be displayed the same way it is in the NMEA string. So when it displays Rtk, that means you have a fixed RTK solution.

     GGA          Global Positioning System Fix Data
 123519       Fix taken at 12:35:19 UTC
 4807.038,N   Latitude 48 deg 07.038' N
 01131.000,E  Longitude 11 deg 31.000' E
 1            Fix quality: 0 = invalid
                           1 = GPS fix (SPS)
                           2 = DGPS fix
                           3 = PPS fix
		       4 = Rtk
		       5 = FloatRtk
                           6 = estimated (dead reckoning) (2.3 feature)
		       7 = Manual input mode
		       8 = Simulation mode
 08           Number of satellites being tracked
 0.9          Horizontal dilution of position
 545.4,M      Altitude, Meters, above mean sea level
 46.9,M       Height of geoid (mean sea level) above WGS84
                  ellipsoid
 (empty field) time in seconds since last DGPS update
 (empty field) DGPS station ID number
 *47          the checksum data, always begins with *

After you’ve connected it will load your points file for stake-out - simply select the point you wish to stake and hit the stakeout button. It will display the deltas to the coordinate you’re looking for.

There are still a few bugs to work out, and more features to be added. I haven’t had an opportunity to test this app on many different devices and builds of android so you’ll have to forgive me if it doesn’t work on one of the million variants of android floating around out there. I will do my best to fix the bugs I’ve found already.

The APK can be found here

Also, you wont have to use mock locations either. The data is all handled by the app rather than use any of the proprietary GNSS functions of the devices.

11 Likes

@surveyor,

Any updates here on your progress on the app?

Thanks!

Where can we access the APK?

I’ve looked on the docs but nothing found.

Just use an apk downloader site. There are several on the net.