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Trimble R2 unable to achieve sub-foot accuracies

  • 1.  Trimble R2 unable to achieve sub-foot accuracies

    Posted 05-23-2022 10:57
      |   view attached

    Hello,

    We have a Trimble R2 GPS with a sub-foot subscription giving us accuracy issues. The accuracy ranges from 20 to 30 inches when connected to NTRIP.  We have had other units side-by-side, and they get 2.8 inches accuracy. Our organization uses a Samsung Galaxy Tab S3, GNSS Status. These are the settings we have applied: 

    1. Samsung Galaxy Tab S3:
    - Enabled developer settings
    - Forced full GNSS measurements through GNSS Status
    - Connect via Bluetooth to the receiver

    2. GNSS Status:
    -  Corrections we applied:
        . Primary: Internet
        . Server settings: enter the IP address and port number
        . NTRIP  Source: VRS_CMRp
        . Login Details: entered our VRS subscription username and password 
        . Secondary: SBAS

    We have tried different mount points, CMR+ and CMRx. Also, we tried switching from NTRIP to RTX.
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    Other solutions we have tried without success:
    - switching to Fieldmaps and TMM on the Galaxy Tab S3
    - used an Apple Device with GNSS Status and ESRI Collector
    - used an Apple device with TMM and ArcGIS Field Maps
    --------------------------------------------------------------------------------------------------------------------------------------------
    There is an attached photo showing a side-by-side comparison the accuracy difference when next to a unit that also has a sub-foot subscription.



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    Shane Hertzog
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  • 2.  RE: Trimble R2 unable to achieve sub-foot accuracies

    Posted 05-24-2022 07:19
    Edited by Paul Lohr 05-24-2022 07:19
    Hi, Shane.

    Do you have the option to choose one of the RTCM data formats? I see that you have tried CMR+ and CMRx.

    You still may need to try various mount points in order to find a network solution or single baseline that works for you.

    It can be helpful to use rtklib (free) to see the messages that are being returned by the RTK server. As far as I know, those messages are not displayed by GNSS Status or by Trimble Mobile Manager.  If you try rtklib, use the strsvr.exe program to get started. The RTK server that we use allows only a single login of an account at any one time. So disconnect any other devices before logging in with rtklib.

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    Paul Lohr
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  • 3.  RE: Trimble R2 unable to achieve sub-foot accuracies

    Posted 05-25-2022 07:07
    You may want to check to make sure the sub-foot (dm) option was applied to the unit.  You can hook it up to the Trimble Installation Manager and it will show what options have been applied.
    Just off the top of my head, that what it sounds like


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    Doug Kotnik
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