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The Trimble Mobile Manager app provides configuration tools for users to output positions in either a local or a global reference frame.

In Trimble Mobile manager (TMM) this is known as the GNSS output Reference Frame (GORF)

The GNSS output Reference Frame enables you to define a consistent coordinate output regardless of the correction source in use and to also compensate for datum/epoch shift errors.

Please refer to the Trimble Mobile Manager Quick Start Guide for more information on this topic

In ESRI Collector you will need to create a Location Profile and match the GNSS Receiver Coordinate System with the Target Reference Frame setting in TMM.

Setting the GNSS Output Reference frame in Trimble Mobile Manager

1. Select the More menu  then select Corrections 
2. Select the GNSS output reference detection mode and choose from one of the 3 options:
   • Same as Source  (Transformation Off) - Trimble Mobile Manager (TMM) passes through positions as received by the receiver (whether they are corrected or not). Practically this means ITRF2014(Current - WGS84 equivalent) or whatever your local NTRIP source is using if you are using a local base
   • Auto select - Trimble Mobile Manager queries the current position to look up the reference frame you are most likely in based on internal polygons of known frames 
   • Select from list - Select your reference frame from the support datum's provided. Refer to Supported Geodetic Datum's in Trimble Mobile Manager for the full list
3. Select the More menu to return to the TMM options menu

As an Example; If you are working in the European Region and enable Auto selection TMM will choose ETRF2000(R05);2000.00: EPSG1186 or whatever the appropriate Datum isfor your location 

Select the Main Menu > Corrections option	Set GNSS Output reference detection mode	Select your preferred option to apply	Connect to Catalyst & observe the GNSS output Target Reference Frame under the STATUS menu

Note - The GNSS output reference frame in TMM also sets the output EPSG code, which can be queried and used as position meta-data for other Catalyst-enabled applications utilising Trimble Mobile Manager. For more information on EPSG codes and their use, refer to the official website http://www.epsg.org/.

Configuring Location Profile In ESRI Collector  

In ESRI Collector you will need to create a Location Profile and match the GNSS Receiver Coordinate System with the GNSS output Reference Frame setting in TMM

1. Ensure Catalyst is disconnected in Trimble Mobile Manager (or any other Catalyst enabled apps) so ESRI Collector can connect
2. Start ESRI Collector and Sign In
3. In the Map Overview Window select the overflow option and Settings
   
   
4. Under the Location section, select Location profile and Add profile 
     
   
   
5. First you must define the GNSS Receiver Coordinate System - this is the TRF define earlier in TMM
6. Type in the EPSG or name of the GNSS output Reference Frame defined in TMM
7. Select the appropriate GCS from the list - for example 4258 is the EPSG for GCS ETRS 1989
   Please refer to the ESRI GNSS Receiver Coordinate System Lookup Table below which provides the current EPSG codes output by Trimble Mobile Manager and the GCS equivalent in ESRI Collector - for all supported Datum's please refer to the Supported Geodetic Datum's in Trimble Mobile Manager document
    
8. Define the Map Coordinate System (this is the coordinate system your basemap is using) - For example ArcGIS Online uses the WGS84 Web Meractor Auxillary projection
9. Select the Datum Transformation between your GNSS Receiver Coordinate system and the map coordinate system
   Note collector does not support Grid Transformations currently
10. Save and name the profile
11. Select to use
    
    

For simplicity we recommend Selecting the WGS84(G1762) current option from the list in TMM and setting GCS WGS 1984(4326) In ESRI Collector. This requires no Datum transformation so will enable you to transform this back in ArcGIS If your Datum Transform Is not supported in Collector

ESRI GNSS Receiver Coordinate System** Lookup Table

*  ESRI Collector does not yet support  ITRF2014(current) so this is the best approximation.

** Trimble Mobile Manager does not apply a deformation models for the associated datum. In this case you should use the Same as source (Transformation off) option and apply the correct transformations independently (In your desktop software for example), or perform a site calibration using a 3rd party application to adjust for localised differences.

Why Is there a difference In EPSG Codes?

TMM displays the EPSG based on type = Geodetic Datum, while ESRI Collector displays are based on type = Geodetic CRS (geographic 2D)
For more information on EPSG codes and their use, refer to the official website http://www.epsg.org/.

General best Practice

If the user has "No transformation" set in TMM:

• Set the GCS that best matches the Trimble Correction Hub (TCH) Datum Correction Source
• For Local NTRIP corrections, you should choose a datum that best matches the correction datum of your local NTRIP network. This should be known by the local network administrators.

If the user chooses Auto selection:

• Auto selection queries your current position and looks up the most likely reference frame (and epoch) for your location based on internal polygons of known frames.
  • The Reference Frame is then displayed in GNSS output Reference Frame field under the STATUS menu in TMM
  • In ESRI Collector you should choose the closest GCS based on what is displayed in the TMM GNSS output Reference Frame field
  • This is recommended if you are unsure what you should use,
  • For example in Europe this would revert to ETRF2000(R05), the US NAD83(2011), In Australia GDA94
• For Local NTRIP corrections, you should choose a datum that best matches the correction datum of your local NTRIP network. This should be known by the local network administrators.

If the user chooses Select from list:

• Set the GCS that best matches the TCH Datum Correction Source you have selected from the list
  • The table in Supported Geodetic Datum's in Trimble Mobile Manager  covers all the supported Reference Frames along with the EPSG Code
  • TMM displays EPSG codes based on Geodetic Datums, while ESRI Collector displays are based on Geodetic CRS (geographic 2D)
  • You can search by EPSG in ESRI Collector and use the official website http://www.epsg.org to find the equivalent or best approximation to set up in ESRI Collector
• For Local NTRIP corrections, you should choose a datum that best matches the correction datum of your local NTRIP network. This should be known by the local network administrators.