androidgpsmobiletrimble
I want to develop a mobile app that can use external GPS as source for collecting high accurate point.
And I just found how to connect Trimble R1 or Trimble R2 to android device using bluetooth based on 'GNSS status' App and allowing 'Mock Location' on developer options in the android device…
So, I just wonder how to apply the same issue with other Trimble devices such as R3 and R4?
Any ideas or suggestions?
I've done exactly the same thing for the same purposes - creating GIS-based rock climbing guides using GPS points taken with a mobile phone. I collected my points using an iPhone and the iGIS app. What I liked about iGIS was its ability to read/write directly to shapefiles, so you can get your attribute schema all setup outside of the app.
Screenshot of some climbing route points that were collected:
As far as improving the accuracy of taking GPS points under cliffs and in tree cover - there's not alot you can do (especially using a phone). Speaking from personal experience, even a survey-grade RTK GPS unit struggles under these conditions to get a lock sufficient for taking high accuracy locations. This is due to interference and obstruction of the signals the unit is trying to reconcile to produce accurate point solutions.
For a rock climbing guide, however, the points likely don't need highly accurate absolute positions (exact lat/long coordinates for example), but rather accurate relative positions to each other (so that once a climber gets to a certain area in the guide, they can easily distinguish nearby routes from one another).
Using a phone, my methodology to try to get things as accurate as possible were: 1) take multiple points as you were doing and average the coordinates 2) near large cliff faces, if possible take the points at right angles away from the cliff so that the cliff is less of an obstruction; and then move the points back to the cliff face during the mapping phase using aerial imagery or topographic data 3) for close-space climbing routes, take control points in areas that are less obstructed, and then use a long tape measure to take measurements from those control points to the routes; then map the points using your sketches later
A sample of the finished guide:
I’ve used the Bluetooth GPS app from Google Play to connect an android tablet to an external NMEA GPS over Bluetooth.
Best Answer
I do not believe you are comparing apples to apples here. The R1 and R2 are are MGIS products (I realize the R2 can also be used by Trimble Access) and the use of 3rd party software is more likely, whereas the R3 (L1 only), R4 all the way to the R10 are survey receivers. The survey receivers typically require a specialized software, like Trimble Access to configure and utilize. Once configured you could send the NMEA data to a 3rd party device if that device supports the bluetooth connection or a cabled connection.
Trimble may have some sort of SDK for their survey GNSS receivers, but it is doubtful.
I would recommend contacting a local Trimble dealer or Trimble themself. We did the same with Leica when we wanted more information on the Android version of their Zeno 20 device. It was easy to navigate their channels and even easier to work with on the questions we had.