Managing and understanding settings

To post-process collected feature data, continuously logged data from a nearby base station (at a precisely known location) is also required. The idea is that the errors (atmospheric, etc.) in the collected data are comparable to that at the base station and so they can be removed through the process of differential correction. For this purpose, Trimble maintains and distributes a global database of continuously operating community base stations (CBS). While most of the stations in the database provide data for free, some of the networks are subscription-based and require a username and password. This CBS database is integrated into Terra Office. In order to simplify the process of base station selection and improve repeatability, Terra Office uses the concept of Processing Profiles. A processing profile is a base station (system or user-defined) along with settings.

For more information on differential correction, consult the following site:

https://geospatialresources.trimble.com/blog/gps-101-learn-how-gps-works

To create a processing profile:

1. As the community base stations are sorted based on proximity, it is best to start by having the current map document centered on the area where you intend to collect data. This does not have to be precise; a general area (city scale) is fine.

2. Click the Terra Office Settings button on the toolbar.

3. In the Settings window that opens, click the Processing Profiles button.

   The window will change to show the Processing Profiles and you will see a list of profiles previously created. The list shows the Profile Name and a Description for each profile.

4. Click Create… .

5. In the Edit Profile window that opens, provide a Profile Name and make a choice for how you will Search for Base Station Data:

   • Using a single base station: For picking a base station from the Trimble database. This is the most common option and is what the rest of the steps in this section refer to.

   • Using a folder of specific base station data files: For specifying a local folder if you have sourced the necessary base station files yourself.

6. To select a base station, click Select… next to the Using a single base station entry box.

7. In the Select Base Station window that opens, choose a Base Station from the list. By default, the list will be sorted by distance to the Current map center but you can also pick a (medium-to-large size) City from the list and use that search option. The columns in the list indicate the Base Station name (typically including the name of the provider or network), the presence of L2 frequencies and GLONASS satellites in the logged data, and the Distance from the chosen search option.

8. To view specific properties of a base station, select it in the list and click Properties… . The Base Station Properties window that opens organizes content into 5 tabs:

   • General: Basic information about the station owner and general location.

   • Base Station: Technical information about the receiver type, software, and supported GNSS constellations.

   • Reference Position: The reference position(s) of the base station in different reference frames (datums) and the reference frame of the base station reference position as stored in the base data (Rinex) files. There are generally two sources of reference positions for a given base station - the Trimble database (CBS) and the base data (Rinex) file headers. The former is maintained by Trimble and in most cases will contain reference positions in multiple reference frames (i.e., global and local). The latter is maintained by the base station provider and is sometimes, but not always, the most accurate and well-maintained position assuming the reference frame is known.

   • Internet Server: The URL templates and other information necessary for Terra Office to be able to download data for this base station.

   • Security: For subscription or restricted access base stations, the username and password that can be used to download data.

9. To make changes to any properties of a system-defined base station (e.g., to add a username and password if required), make a copy of it by selecting it in the list and clicking Copy… . This creates a user-defined base station and you can then make any changes to it. You can also create a new base station from scratch by clicking New… .

10. With the desired base station selected in the Select Base Station window, click OK to return to the Edit Profile window. You should see your selection in the text box below the first radio button.

11. In the Processing Options area, there are three important settings to note or change:

    • Select last corrected results regardless of accuracy: When selected, the last post-processing results will always be used to update feature geometries. When not selected, Terra Office will only use the last post-processing results if they result in better accuracy than what exists currently; this comparison is done on a position-by-position basis and so a finished feature geometry can consist of a mix of results.

    • Correct real-time corrected positions: When selected, positions corrected in real-time will also be post-processed; whether or not they get used in the feature geometry depends on the setting immediately above. When not selected, positions corrected in real-time will never be post-processed and will thus always be used in the feature geometries.

    • Use reference position from: This controls which reference position (and frame) will be used for the base station. For some networks (e.g., NGS CORS), the provider or network is known to provide authoritative reference positions in the Rinex files and this will be noted. In general, leaving the default setting here will provide the best results. For more information on Processing Profile Reference Position Handling, consult the section below or use the More info text link in the window.

12. Click OK to store the processing profile and return to the Processing Profiles list window. The processing profile is ready to be used for Processing collected data.

To edit an existing processing profile, select it in the list and click Edit… . To remove an existing profile, select it in the list and click Remove button.

Periodically, Trimble updates the community base station database content with new and updated entries. To update the content in Terra Office:

1. Click the Terra Office Settings button on the toolbar.

2. In the Settings window that opens, click Base Stations.

   The window will change to show the Base Stations database summary.

3. Click the Download and update from the latest version published by Trimble text link. This will download the latest version and update what’s in Terra Office. Existing user-defined base stations will be maintained.

4. To update or import user-defined base stations from another database (e.g., from a different user or from a Trimble distributor), click the Update user defined base station records… text link and in the file browse window that opens, select the other database or user_list.xml file (older format).

5. To export all user-defined base stations in your current database (e.g., to share with someone else), click the Export user defined stations… text link and in the file save window that opens, provide a path and name for the database file.

While generally covered in Creating and managing projects and the Project Wizard steps, there are a few important things to realize about real-time correction profiles in Terra Office.

• The real-time correction profiles are used only in TerraFlex Cloud and TerraFlex Local workflows.

• The list of real-time correction profiles presented in the Accuracy Settings page of the Project Wizard is common to all projects; profiles can be shared among local TerraFlex Cloud and TerraFlex Local projects provided they are not used across multiple Trimble Connect projects.

• The real-time correction profile can specify both a primary (RTX - Internet, RTX - Satellite, Internet, Serial Port, SBAS) and secondary (SBAS) correction source and offers a more granularity than the authoring experience in the Trimble Connect Map Viewer. Internet-type correction sources (e.g., VRS or single-base RTK networks) can be NTRIP or Direct.

• During authoring of an Internet correction source, you would typically provide a Username and Password if they are required by the source. If they are required but not stored with the configuration, the TerraFlex user will be prompted to provide them the first time they select that profile.

• In Terra Office, real-time correction profiles are referred to as Field Configurations as they contain a few more properties than just the real-time configuration source(s). On the last step of the Create Field Configuration wizard (the page is called Logging Settings), you are able to specify two settings for the predicted post-processing accuracy (PPA) calculator used in TerraFlex. The Postprocessing Base Distance and Base Data (constellation) settings can be changed from their default values when you know more specifically what base station you intend to use for post-processing. For example, if you know that you typically work within 25km of a base station that logs Galileo satellites in addition to GPS and GLONASS, you can change those two settings to improve PPA convergence time in the field. This applies regardless of where the data will be post-processed - in the cloud with offline GNSS corrections or on the desktop, manually, in Terra Office.

  If you are only using post-processing without any real-time correction source, you can still create a local field configuration with just these two logging settings specified, and include it with the project.

When data is first downloaded or checked-in from a particular user (TerraFlex workflows) or device (TerraSync workflows), Terra Office adds that user/device to an internal Devices table in the database. To make the User/Device column easier to read or understand in the Session Manager mode of the Field Data dockable window, it may be desirable to provide a friendly, or common name for the user/device. For example, instead of “Device_1”, you may want to say “Crew 1 TDC” or instead of “Matt Morris (matthew_morris@trimble.com)”, you may just want to say “Matt’s R2”. You can also associate a default Processing profile with a Device to allow for simpler selection when Processing collected data.

To make changes to the Devices stored in Terra Office:

1. Click the Terra Office Settings button on the toolbar.

2. In the Settings window that opens, click Devices.

3. The window will change to show the Devices and you will see a list of devices (and/or users) known to Terra Office.

4. To change the name of a device (will be immediately reflected in the session list if open), select it in the list and click Edit…. Provide a new Name and click Save. The Serial no field is generally unused.

5. To associate a profile with a device or user (can be multiple), select it (or them) in the list and click Set Profile…. Select the desired profile in the context menu that opens. You can also select None to clear the desired profile. In general, picking a profile here will just set it to the top of the list in the Correct Sessions window; you can still pick any profile compatible with the project geodetics.

To remove a device or user, select it in the list and click Remove . If data from that device or user is downloaded or checked-in in the future, an entry for it will be re-added.

The Feature Type Library provides basic functionality for re-using layer settings across projects that use the same geodatabase feature class sources. In general, a layer or feature class name can only be used once in the Feature Type Library. It may be necessary to remove/add entries in the library as you work in different geodatabases. Entries in the library will generally only be compatible within TerraFlex OR TerraSync project types—and cannot be used across both as the metadata and auto-collected fields are different.

Once entries exist in the Feature Type Library, they will be searched when Creating and managing projects if the Load feature settings from Feature Type library checkbox on the Layers step of the Project Wizard has been checked.

To add a layer from an existing project to the Feature Type Library:

1. Click the Terra Office Settings button on the toolbar.

2. In the Settings window that opens, click the Feature Type Library button.

   The window changes to show the Feature Type Library and you will see a list of existing Feature types in the library. Initially, it will be empty.

3. Click Add… .

4. In the Add Feature Types window that opens, select an existing project from the Select a project dropdown. All project layers will be shown in the Select feature types list.

5. Select the desired project layer from the list and click Add. The window will close.

6. In the Feature Type Library window, note the new feature type that was added. Select it to view the Feature type properties. These will be re-used in future projects that reference this layer.

To remove a feature type from the list, select it and click Remove. This only removes that feature type from the Feature Type Library and does not affect any existing projects that use that feature type (layer).