High accuracy data logging by using a RTK TOP608BT GNSS receiver.

Posted by jack wu on

System requirements:

  • Android phone / tablet with Internet connection (typically cellular based, 3G, 4G LTE or 5G, only requires 1-2 KB/second)

  • RTK capable GNSS Receiver
  • NTRIP Server login info(which provide RTK correction data)
- NTRIP Server/Caster IP address or / full qualify domain name
- Port number
- userid
- password
  • NTRIP Client on Android (For example, Lefebure NTRIP client)
  • GPS data logging app on Android (For example, "GPS Logger" app)


NTRIP data flow diagram:

NTRIP data flow diagram


Connection Instructions:

Section A:

Pairing the bluetooth GNSS receiver (step 1 - 3).

1. In your Android device, go to Settings -> Device Connection -> Bluetooth -> Available Devices, you will see your bluetooth GNSS receiver. If not, please scan for the device.

TOP608 scan bluetooth

2. Tap the GNSS receiver ("TOPGNSS" on the below screenshot) under the available devices, it will prompt for “Bluetooth pairing request". Please key in "1234" as the PIN code & tap the “ok” button.

TOP608 bluetooth pair code

3. The GNSS receiver("TOPGNSS" on the below screenshot) has been successfully paired with your Android device.

TOP608 bluetooth paired


Section B: 

Install NTRIP Client. (step 4)

4. In the Android “play store” download and install the “Lefebure NTRIP Client” app.

Install Lefebure NTRIP client

Section C: 

Use "Lefebure NTRIP client" as the mock location app, so that the location data from the RTK GNSS receiver can be shared to the apps on this Android device. (step 5 - 6)

5. From the Android main screen , go into settings -> System & update -> Developer options -> Debugging -> Select mock location app.

TOP608 Android developer options

TOP608 select Mock Location

(“developer options” menu is hidden by default. To show it, go to Settings -> About Phone and tap on ‘Build Number’ seven times. )


6. Select the “Lefebure NTRIP Client” app.

 TOP608 Select Lefebure NTRIP client as mock location provider


Section D: 

Config the Lefebure NTRIP Client. (Step 7 - 16)

7. Launch “Lefebure NTRIP Client” app, then click the “gear” icon.

TOP608 Lefebure NTRIP client setting


8. Select “Receiver Settings”.

TOP608 NTRIP Client receiver settings

9. Select "Receiver connection".

TOP608 NTRIP Client receiver connection


10. Select”External via Bluetooth”.

TOP608 NTRIP client select bluetooth device


11. Select “TOPGNSS”.

select topgnss - rtk setup

12. In the "Receiver Settings" menu, check “GPS Mock Locations".

TOP608 NTRIP client select Mock in Android

13. Back the menu one level up. You will see the “Lefebure NTRIP Client-Settings” menu. Then select “NTRIP Settings”.

TOP608 NTRIP Client Settings

14. Select “Receiver Connection”.

TOP608 NTRIP client Receiver connection

15. Select “NTRIP v1.0”.

TOP608 NTRIP v1.0 Network Protocol

16. Key in the below settings:
Caster IP: the NTRIP server / caster IP address / fully qualified domain name.
Caster Port: the NTRIP server / Caster port number.
Username: from your NTRIP service provider.
Password: from your NTRIP service provider.
You can save these settings into a profile by select “Saved Profiles”

TOP608 NTRIP client Settings

You need a NTRIP caster login account to continue. If you do not already have one, please get one before going forward. Below are some NTRIP correction service resources. You can always get an NTRIP account from the source you prefer.

Rtk2go (free service, world wide coverage)
UNAVCO (free service, US coverage)

Section E:

Stream the NTRIP correction data to from NTRIP caster --> Android device --> RTK GNSS Receiver(TOP608BT). (step 17 - 20)

17. When done, back to the NTRIP Client main screen. & press the “connect” button.

TOP608 Lefebure NTRIP Client connection button

18. If the NTRIP configuration key is correctly, the NTRIP service provider will return a stream List as the below. select a mount point(stream) which is the closest to your current location. You can get the mount points from your NTRIP service provider's website.

TOP608 RTK mount point (stream)

19. The NTRIP client main screen will have a progress bar showing the correction data(RTCM) is downloaded from NTRIP caster to the RTK GNSS receiver through the Android device.

TOP608 RTK connected

20. If your RTK GNSS receiver is under an open sky area, in about a minute, you might see the Fix mode changed from “FloatRTK” to “RTK”.


Your RTK GNSS receiver has been successfully set up.


Section F: 

Use GPS logger app to do high accuracy data logging (step 21 - 22).

21. In the Android “play store” download and install “GPS Logger” app.


GPS Logger app for Android


22. Start using "GPS logger" app to do high accuracy data logging. Please refer to the below screenshot.

RTK GPS logger


Congratulations! Now you have RTK high accuracy GPS logger ready to use!

TOP608BT Bluetooth GPS/GNSS receivers can be purchased from here.

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