Mapping and GIS Solutions Community

Introduction

When support for local coordinate systems (including orthometric heights) was added to TerraFlex workflows in December of 2020, the entire solution became much more complex. As the functionality matured over the next few releases, there were changes made to many parts of the system (cloud storage, API methods, desktop API consumption, etc.). In some cases, these changes introduced bugs into the Trimble Positions and TerraFlex Desktop add-in workflows. Specifically, form geometries downloaded into the geodatabase could become incorrect under certain circumstances. This only affected workspaces published from the add-ins that utilized a local coordinate system and/or were set to use orthometric heights and for which the workflow was configured for real-time corrections only (form downloads). Of note, US customers were particularly affected. There were a few public Support Notes and dealer-facing Support Bulletins in the first half of 2021 dealing with this, in addition to support cases and Trimble- and distributor-lead communications with users.

Here is a brief summary of the conditions under which incorrect form geometries could be stored in the geodatabase:

• Forms downloaded more than once; forms could be shifted by a datum offset after the 2nd download
  [downloaded 01 Dec 2020 - 30 Mar 2021, 01 June 2021 - 19 July 2021]
• Forms downloaded in large numbers (>50 at once); forms downloaded later in the set could have a shifted x/y and an incorrect z value (wrong unit conversion)
  [downloaded since 01 Dec 2020]
• Forms losing their geometry entirely when downloaded a 2nd time
  [downloaded 18-27 Apr 2021]

If cloud-side data became incorrect as a result of these bugs, it was fixed in-place and the form geometries as collected in the field were restored as necessary. In general, the recommendation to users was to redownload their collected data to ensure that correct form geometries were fully propagated into the geodatabase. However, this can be a time-consuming process especially if the forms included photo attachments. Additionally, any changes made through ArcMap to a feature after it was downloaded would be lost when the form was redownloaded.

In an effort to make it easier to identify (and fix) problematic feature geometries in previously downloaded data, we have provided a new Feature Geometry Integrity Checker Tool in the add-in versions listed below. This tool can be used to scan all previously downloaded form geometries (within a project and layer), get a list of features that have a different geometry, and apply a fix to the geometry (and feature height metadata) only. No other feature attributes are affected nor are any photo attachments re-downloaded. Of course users still have the option of re-downloading all forms instead of using the tool - that will also serve to make sure users have the correct data.

The tool is available in these add-in versions:

• Trimble Positions Desktop add-in v10.8.1.3
• TerraFlex Desktop add-in v5.4

Adding the Tool to the Toolbar

The new Feature Geometry Integrity Checker Tool is not on the add-in toolbar by default. To add it, you must use ArcMap's built-in functionality for customizing toolbars:

1. Right-click in ArcMap's toolbar area, scroll to the bottom of the (long) toolbar list, and click Customize.... This will open the standard ArcMap Customize Toolbars dialog box:
   
2. Click on the Commands tab and in the Show command containing textbox, type "feature geometry". Depending on what add-in you are using, you should see tool listed (as a Command):
   
   Note: For Trimble Positions Desktop add-in, the Category will be "Trimble Positions Controls" while for the TerraFlex Desktop add-in, the Category will be "Trimble TerraFlex Controls".
   
   
3. Click the Command entry for the appropriate TerraFlex Feature Geometry Integrity Checker Tool and drag it to the add-in toolbar:
   
4. Close the Customize dialog and confirm that you see the tool icon on the add-in toolbar:
   
   

Using the Tool

The tool can be launched from the new button added above. It will launch the tool if the currently open add-in project meets the criteria listed above (anything other than WGS84 using HAE heights in meters). When clicked, a single dialog window will open:


Each layer in the current project is represented in the Layer select list. Pick the desired layer and click the Download and check forms button. Horizontal and vertical thresholds can be changed if desired. A summary will be presented at the bottom of the window:

If geometries with differences ARE found, the window will present a list of such features with the ability to select them. Click on a row to select the feature in the map for reference (not required).

Note: The screen below is representative of the issue with a datum shift introduced in certain time periods when forms were downloaded more than once.

By default, all features with different geometries will be selected, but any feature can be de-selected as desired.

Click the Update Selected button to update the feature geometries in the geodatabase for this layer and project.


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#positions
#esri
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