New downloads for August 2014 release

After the initial release on August 8th, we found some minor issues in a couple of the products. We have fixed these issues and updated the downloads accordingly. There is no change in version number or documentation.

If you had already installed the initial August 2014 release for any of the products prior to August 22nd, it is highly recommended to uninstall the products, download the updated installers, and re-install the products.

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Trimble TerraFlex Desktop add-in

Those of you who are using (or considering using) Trimble TerraFlex are most likely aware of the new release earlier this week. Included in this release is the Trimble TerraFlex Desktop add-in, an ArcMap add-in that can be used to publish projects from and download completed forms into your existing geodatabase. If you’ve already downloaded and installed it, you’ve probably noticed a number of similarities to the Trimble Positions Desktop add-in.  In fact, they share the same underlying components and quite a bit of source code.  A few things to note:

  • Both products can be installed and enabled at the same time within ArcMap. It is highly recommended to run Positions Desktop add-in version 10.2.2.1 if you intend to run TerraFlex Desktop add-in version 2.0. Trimble does not guarantee compatibility with older versions of Positions Desktop add-in.
  • The TerraFlex Desktop add-in inherits the same ArcMap version support (10.1, 10.2, 10.2.1, 10.2.2) and geodatabase support (file, personal, enterprise) as the Positions Desktop add-in.
  • The ‘default’ TerraFlex Desktop add-in configuration (single-user, built-in Jet database) will not be used if a Positions Desktop add-in configuration (single-user or all-users) is found on the machine. In this case, both add-ins will use the same database connection settings. Although projects and project settings will be stored in the same physical database, they are only visible from the add-in where they were created.
  • When running both add-ins at the same time, only one log file will be used and it will receive messages from both add-ins. Depending on the (internal) order in which the add-ins load within ArcMap, this will either be PositionsDesktopAddIn.log or TerraFlexDesktopAddIn.log in the folder:
C:\Users\<username>\AppData\Roaming\Trimble\Positions\10.1
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Antenna height handling in Trimble Positions

The new version of Trimble Positions includes the following improvements in handling antenna information:

  1. It is possible to specify antenna height when collecting GIS features with Positions Mobile extension for ArcGIS for Windows Mobile. Antenna height is a vertical distance between an antenna and a feature that is collected and will be applied when the GIS feature geometry is collected. For example, if a pole-mounted antenna is used to collect manholes, the length of a pole can be specified as an antenna height. That will enable calculation of precise heights for actual features (manholes). Antenna height will be stored into session data for each logged GNSS position.
  2. It is possible to select a proper antenna type when collecting GIS features with Positions Mobile extension for ArcGIS for Windows Mobile. A selected antenna type and a measurement method will be used to correct antenna height entered by a user to match the actual distance between the antenna’s phase center (the position which is calculated by the GNSS receiver) and GIS feature. Antenna type will be stored in a GNSS session (if created).
  3. The Positions Desktop add-in will use antenna height and type information collected by the Positions Mobile extension and the Positions ArcPad extension if/when feature geometry is recalculated, for example after session correction. Antenna height information will be displayed for each GNSS position logged and antenna type will be shown when session features are displayed in the Positions Desktop add-in dockable window.

In the GNSS Settings page in the Positions Mobile extension there is a new “Antenna” group item which displays currently set antenna height and type.

Positions Mobile extension - GNSS Settings

By clicking on this group it is possible to set antenna height as distance in meters and to select the default antenna type. When selecting antenna type, the selection will depend on the receiver type currently connected or the one last used. If there is more than one potential measurement method for a selected antenna type, the user will be required to select the one that matches his/her needs.

Positions Mobile extension - Set Antenna Positions Mobile extension - Select Antenna Type

It should be noted that the software cannot detect if a wrong antenna type is selected by the user. GNSS receivers may provide information if an external or an internal antenna is connected and that information will be displayed in the GNSS Status page.

Positions Mobile extension - GNSS Status

If a selected antenna type does not match the information coming from a receiver, the Positions Mobile extension will try to use a proper antenna type. For example, if an external antenna type is configured by the user, but an internal antenna is actually detected by a receiver, the Positions Mobile extension will select a default internal antenna type for that receiver for collected sessions. Please note that the user-selected antenna type in the GNSS Settings page will not be changed if a mismatch is detected.

Further, Trimble Positions allows only one antenna type to be used per session. To enforce that, if the Positions Mobile extension detects an antenna disconnect while collecting a session, it will stop logging positions until the original antenna (external or internal) is reconnected. An appropriate “Reconnect antenna” message will be displayed.

When using a rangefinder, the antenna height should be set to denote the distance between an antenna and the center of the rangefinder’s lens. The rest of the height difference between a feature and an antenna will be calculated as part of an offset’s vertical distance component.

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Mean Sea Level heights in Trimble Positions

All heights collected in previous versions of Trimble Positions software were expressed as heights above WGS84 ellipsoid (HAE). The new Positions Desktop add-in 10.2.2.1 and Positions Mobile extension 10.2.0.2 add support for Mean Sea Level (MSL), also known as orthometric height.

Every time a project is created or edited in the Positions Desktop add-in or Positions Mobile Project Center extension it is possible to specify if GIS feature heights will be calculated as HAE or MSL. If GIS features need to have MSL heights, it is necessary to define how the difference between HAE and MSL (known as geoid separation) will be calculated. There are two ways to specify geoid separation:

  • Specifying a numeric value for the geoid separation to be applied. The formula to calculate heights is: HMSL = HHAE – NGS, where NGS is the numeric value specified.
  • Specifying a file containing a geoid model. Trimble Positions uses geoid models from Geoid Grid files (*.ggf). These files contain tables of geoid-ellipsoid separations that are used with the GPS ellipsoid height observations to provide an estimate of elevation.

Elevation settings specified in the Positions Desktop add-in will be applied each time the “Update Features” function is used on sessions for that project. This applies to all types of projects supported by the Positions Desktop add-in, including data collected from ArcPad.  In ArcGIS for Windows Mobile workflows, these elevation settings will also apply to the “Feature Height” metadata value which can be stored in an attribute using the Auto Fill settings in Mobile Project Center (populated in the field and updated in the office during “Update Features”).

If GIS features collected in ArcGIS for Windows Mobile with the Positions Mobile extension need to have MSL heights, then appropriate elevation settings must be specified in the Positions Mobile Project Center extension before a project is saved and deployed to devices. Changing a project’s elevation settings only in the Positions Desktop add-in will not be applied to mobile devices until the project is re-saved in Mobile Project Center and re-deployed.

Geoid (*.ggf) files are not installed with Trimble Positions software. It is the customer’s responsibility to find files that satisfy their needs. Trimble provides a good selection of geoid files and related utilities at http://www.trimble.com/globalTRLTAB.asp?Nav=Collection-71. Selected geoid files need to be downloaded (and unzipped) to the folder:

<Common app data>\Trimble\Positions\10.1\GeoidFiles

if those should be shared by all users on a computer, or to the folder:

C:\Users\<username>\AppData\Roaming\Trimble\Positions\10.1\GeoidFiles

if to be used only by a particular user.

It is also the customer responsibility to deploy geoid files specified in projects to mobile devices. The Positions Mobile extension will look for referenced geoid files in the device folder:

\My Documents\Positions

Elevation Settings in Positions DesktopElevation Settings in Positions Desktop

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Using ArcGIS for Windows Mobile + Trimble Positions with ArcGIS Online

Here’s an un-narrated YouTube video showing the entire workflow starting from an empty map document:

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What’s New in the August 2014 Release

Hopefully you’ve all heard by now that we’ve released a new version of Trimble Positions. There are some significant new features for users of ArcGIS for Windows Mobile workflows:

  • Support for precise feature heights. This version adds support for antenna height and type for ArcGIS for Windows Mobile workflows (real-time and postprocessed) for the purpose of collecting high-accuracy feature heights. Mobile Project Center users can specify how Height Above Ellipsoid values are converted to Mean Sea Level elevations (or not) using a fixed geoid separation or calculated from a GGF file downloaded from the Trimble website (and deployed manually to the field device). Accordingly, the metadata value formerly known as Height Above Ellipsoid is now named Feature Height.
    Look for a future blog post about using this functionality effectively.
  • Support for ArcGIS Online hosted feature services (real-time only). Previous versions of Trimble Positions Mobile Project Center extension did not allow the user to include hosted feature services from ArcGIS Online in high-accuracy enabled mobile projects. This restriction has now been removed for projects that use a real-time only workflow. In other words, you can collect high-accuracy data directly into ArcGIS Online.
  • Additional hardware support. The Trimble Positions Mobile extension can now run on additional field devices: Trimble Juno® 5 Enhanced GPS, Trimble Juno T41™, and Trimble Juno T41 Enhanced GPS.

Additional information is available in the release notes:

Note: If you have issues upgrading the Trimble Positions Desktop add-in and the old version still appears, it may be worth manually cleaning the entry in ArcMap’s AssemblyCache after uninstalling the old version and before installing the new version.  It’s generally in the following location on Windows 7 (AssemblyCache is a hidden folder):

C:\Users\<user>\AppData\Local\ESRI\Desktop<version>\AssemblyCache\{53B8FB5F-6061-4667-84B8-ADE5C76D6BE3}
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Coordinate Systems and Datum Transformations

As this user community knows, collecting high accuracy data requires a working knowledge of coordinate systems, or spatial references, and datum transformations.  The intent of this (long overdue) post is not to deep dive into these topics but rather to summarize how and where datum transformations are used in Trimble Positions.  Let’s look at the two basic workflows.

[Disclaimer: The reader is assumed to have pre-existing knowledge of coordinate systems, datums, datum transformations, and which of each applies to their data.]

ArcPad Workflow

In an ArcPad workflow, coordinate systems come into play in 3 places: at the geodatabase feature class level where the data is stored, at the ArcMap map document (data frame) level where the data is symbolized and “presented”, and in ArcPad where data is collected.  Esri provides form controls for selecting the coordinate system (geographic or projected) for a feature class and also for the data frame of a map document in ArcMap and ArcCatalog.  When the datums differ, you are prompted for a datum transformation in ArcMap.  In ArcPad, there is no functionality to change the coordinate system of a project or layer, but you CAN change the datum of the GNSS (labeled as ‘GPS’ in this case).  Although both autonomous (uncorrected) GNSS and SBAS-corrected GNSS use the global WGS84 datum, many other real-time correction sources (e.g., VRS or single-base) use a regional datum such as NAD83 (CORS96).  In these cases, you would generally change the GNSS datum in ArcPad to reflect the datum of the real-time source.  ArcPad will then handle the transformation locally to ensure that collected data lines up with checked-out data.

Trimble Positions needs to know about this change in GNSS datum in order for further processing.  This is the purpose of the “Coordinate system for real-time corrections (if applicable)” entry box on both the Check In ArcPad AXF files form (and the Import ArcPad QuickProject form).  You should select a geographic coordinate system for the datum used by your real-time correction source in the field.  You will also be prompted for a datum transformation (to WGS84) if one is not already found in the map document.

ArcPad Check In Form

This ensures that all Trimble Positions session and geometry data (extracted from the SSF) is properly stored as WGS84 data in the Trimble Positions office database.  During check-in, ArcMap and the ArcPad data manager components take care of any other transformations necessary between the collected data in the AXF and the underlying feature classes.

During post processing and geometry reconstruction, all internal calculations are performed in WGS84.  However, an additional transformation may be necessary if your map document (data frame) is using a coordinate system with a different datum.  Trimble Positions will look first in the map document to see if a suitable transformation exists (from WGS84).  If your map document contains at least one WGS84 layer in addition to your other non-WGS84 data layers, then this transformation will likely already have been specified by you and picked up by Trimble Positions.  But if your map document contains no WGS84 layers, then you must use the Datum Transformations area of the Administration Window to specify the appropriate datum transformation from WGS84 to your selected coordinate system (datum).  Click the “Set…” button to choose an appropriate geographic coordinate system for your datum.  You will also be prompted for a datum transformation (to WGS84).

Datum Transformation EntryDatum Transformations List

ArcGIS for Windows Mobile Workflow

The ArcGIS for Windows Mobile workflow is similar in that coordinate systems also come into play in 3 places: at the geodatabase feature class level where the data is stored, at the ArcMap map document (data frame) level where the data is symbolized and “presented”, and in ArcGIS for Windows Mobile where the data is collected.  Mobile map caches generated from ArcMap will use the coordinate system and datum of the map document.  If the map document is published to a mobile map service on ArcGIS for Server, then the map service takes the place of ArcMap and uses the coordinate system and datum of the map document.  Esri provides form controls for selecting the coordinate system (geographic or projected) for a feature class and also for the data frame of a map document in ArcMap and ArcCatalog.  When the datums differ, you are prompted for a datum transformation in ArcMap.

When you create a mobile project using Mobile Project Center, the coordinate system of the first added layer (operational or background; from mobile cache or mobile service) is used for the project; all subsequently added layers must use the same coordinate system.  This is viewable by expanding the “more information” section at the bottom of the Project Properties window.

Project Properties - more informationOnce in the field and using GNSS, ArcGIS for Windows Mobile assumes that GNSS data is always WGS84 and will take care of any transformations between WGS84 and the coordinate system of the project.  The Trimble Positions mobile extension will always store session and geometry information in the WGS84 coordinate system.  When working with non-WGS84 real-time correction sources (e.g., VRS or single-base) through a field configuration, it is important to specify the datum and appropriate datum transformation in the settings.

Field Configuration Settings

This ensures that appropriate transformations are applied when storing the data internally in the Trimble Positions session (and geometry constructions) and when returning GNSS positions to ArcGIS for Windows Mobile.

During synchronization of the mobile cache (or mobile service if using ArcGIS for Server), Esri components will handle any transformations necessary between the coordinate system of the project and that of the underlying feature class.  During the GNSS Enabling step earlier in the workflow, you’ll remember that a TrimbleSessions layer was added to the map document.  This layer will always be in WGS84 and so Trimble Positions will always be able to find an appropriate transformation in the map document (if necessary) during post processing and subsequent feature updating.  Thus it is not necessary to use the Datum Transformations area of the Administration Window in the ArcGIS for Windows Mobile workflow.

Perhaps in a future blog post we can look at coordinate systems, projections, and datum transformations in greater detail.  There is quite a bit of information out there already, including some great content from our dealers.  It is a complex topic to be sure.

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Problems Connecting to an NTRIP Source in Desktop

Some of you may have experienced problems trying to create field configurations for NTRIP-based sources (e.g., VRS or single base). Specifically, you receive an ‘Error retrieving the list of sources‘ message a short time after clicking the ellipses button next to the ‘NTRIP Source’ entry box and no mount points will be displayed in the list.

The underlying problem has to do with how the standard .NET methods in Positions Desktop try to parse the headers in the NTRIP response.  Since the response may not include true HTTP headers, it tries to parse the NTRIP headers instead as though they were HTTP headers and therein lies the problem. Ironically, the presence of a proxy server in your network environment resolves the issue since it injects real HTTP headers in the response.

We’re working to resolve this in the next release, but there is a workaround that can be employed now. Locate the ArcMap.exe.config file (e.g., C:\Program Files (x86)\ArcGIS\Desktop10.1\bin) and edit it to add a <system.net> section at the bottom (after the closing </runtime> tag and before the closing </configuration> tag):

  </runtime>
  <system.net>
    <settings>
      <httpWebRequest useUnsafeHeaderParsing="true" />
    </settings>
  </system.net>
</configuration>

For those of you so inclined, there are numerous articles out there about this general .NET option.

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Problems Downloading CORS Base Station Data – RESOLVED

As of Friday (April 11) afternoon, all issues should be resolved.

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Problems Downloading CORS Base Station Data

Earlier today we became aware of a problem downloading CORS base station data from the NGS/NOAA servers through Trimble Positions Desktop add-in.  At the beginning of post processing, you will see error messages for the failed downloads.  We are currently investigating the issue but it appears to affect Pathfinder Office and Field Inspector in addition to Trimble Positions.  One workaround would be to note the URLs for the attempted downloads and then download the files manually through a browser.  You can then setup a new post processing profile for those specific files.

We’ll share additional information as we have it.

UPDATE: As of Friday (April 11) afternoon, all issues should be resolved.

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