Summary

The Trimble Precision SDK (TPSDK) is an application interface that allows developers to integrate Trimble hardware technology into their own software integrations. It is designed to provide a set of lightweight components suitable for field collection applications. The developer can choose the desired functionality based on the collection program’s needs. The target applications for the Trimble Precision SDK are applications that utilize Trimble technology in environments that are not supported by Trimble and is designed to provide an interface between the existing ProStar software and Trimble instruments.

There are core and advanced functionality that can be incorporated into the software. The core libraries have no cost to the developer of end-user, and this is what we are currently looking at implementing.  The differentiation is typically core components that provide raw data. Advanced components take the raw data and perform actions (math, workflows, etc.) on top of the raw data. It may be to the developer’s advantage to internally develop the functions that reside in the advanced interfaces to be specific to the collection application, and the developers targeted users.

The core routines have two interfaces:

  • Sensor Software Interface (SSI)
  • Controller Software Interface (CSI)

SSI is an object-oriented driver for Trimble instruments like total stations or GNSS receivers

CSI is an interface for retrieving device serials for licensing, tools for Bluetooth etc.

Advanced GNSS (AdvGNSS)  and Advanced TS (AdvTS) are additional components of the TPSDK and are part of the SSI interface – but these require a separate license. The Spatial Imaging Library (SIL) is also a separate advanced component that requires a separate license.

Integration of Trimble Receivers into PointMan

Many of ProStar’s clients are already embedded into the Trimble hardware ecosystem and Integration of the Trimble positioning systems allows users to leverage a common hardware positioning source with PointMan, which provides a future proof solution. The ability to integrate high end receivers will enable their clients to leverage existing hardware investments and allows them to seamlessly embed ProStar’s software solutions within their organizations. The initial integrations with Trimble allowed for a starting point, but future integrations with the Trimble Precision Software Development Kit (TPSDK) will enable more efficiency and trust within various industries serviced by ProStar. As this will now use the fully supported and tested by Trimble hardware integrations.  This give a level of reliability and comfort that a client’s investments in Trimble hardware and ProStar software will be carried on and supported in the future.

PointMan includes tools and features for survey, photo, sketch and form creation workflows. In order to utilize Trimble tools inside the data collector, there are two connections needed for Trimble receivers to bring location data into PointMan:

  • Bluetooth is standard for all tools
  • A Wi-Fi connection is required for more advanced receivers such as the R10 and SPS985.

Bluetooth connections presently work by default, but PointMan needs to know what data to pull via the Bluetooth connection. For this effort, an understanding of the Bluetooth protocol is necessary. For PointMan purposes, we are concerned with the messages inside the standard GNSS NMEA 0183 strings. Our previous process involved the decoding of the NMEA message string, parsing out each field and saving it as a feature attribute in PointMan. Implementing the Trimble Precision SDK (TPSDK) means that the Wi-Fi connections are no longer necessary to setup the NMEA string through the receiver’s admin page. The TPSDK allows the native connection of the Trimble hardware receivers to the PointMan solution. The use of the TPSDK also allows us to decode more detailed  data streams from the higher precision receivers (R2 & R10 and future models) that contain information on the positional and timing errors which will allow detailed statistical measures of the accuracy and precision to be calculated.

Current Trimble Integrations with PointMan

PointMan currently supports the following Trimble receivers:

Android 7.1 and Up:

  • R1 (Bluetooth Only: No Wi-Fi required)
  • R2, R10, SPS985 (Bluetooth and Wi-Fi required)

iOS 12 and Up:

  • R10 (Bluetooth and Wi-Fi required)

Trimble TPSDK Integrations with PointMan

Starting in 2020, ProStar plans to integrate the following Trimble products into the PointMan mobile data collector:

 

  • TPSDK to become Catalyst-enabled (2020)
  • TPSDK to integrate ALL R-series receivers including R12 (2021)
  • SX Scanner Integration (2021) – Advanced Functionality
  • PointMan for Windows (Trimble TSC7 and T10 – 2021)
  • Integration with iOS – Awaiting Trimble Support for iOS

Trimble TPSDK Use Cases

In many cases the use of higher precision GNSS hardware is required to meet specified accuracy and reliability goals. In general consumer level receivers such as those found on most smartphones or tablets are subject to signal degradation due to limited observation data as they will not generally use all available GNSS constellations and frequencies. In most cases they are limited to the L1/E1 and L5/E5a signals and in the rarer case of tracking the Beidou and Glonass constellations that observation data will also be limited to the single frequency L1 range.

Due to the inherent limitation on the number of channels within these types of consumer level receivers any multiple frequencies will be limited to a subset of satellites and in general only single frequencies are used. In addition, the use of a shared antenna for communications purposes like Bluetooth and Wi-Fi  which generally uses a linearly polarized signal as opposed to the circularly polarized GNSS signal will entail a deteriorating navigation signal as well as a lower signal to noise ratio as a compromise. Other internal RF noise sources inherent in the electronics of the devices which may not be shielded from the antenna will make it more difficult to acquire and track the GNSS signals, more so in sky obstructed areas.

It is these inherent factors that will limit the accuracy, precision and reliability of the navigation signal in horizontal positioning and a great deal more if a vertical component is desired. 

GIS data collection is a area that many applications have espoused the use of more consumer level GNSS receivers, this may work in areas of open skies and limited signal interference where the vertical component is not of critical concern but in most cases even if the elevation is not required it is a very useful piece of information that makes the position far more useful for other purposes. It is better to collect the information than to repeat the field operation later.  In cases where there are urban canyons or obstructions it may seem as it the position is available but the signal degradation and interference will impact the accuracy and precision and it may not make it evident to the field operation as few consumer level devices give concise measures of the precision as it is collected. In these cases the use of higher level receivers and more importantly the use of a proper calibrated antenna will alleviate the possibility of either returning to the field at another time or in a much worse case, not knowing that the data is of poor quality and making decisions based on poor data.

One ideal hardware configuration for GIS data collection use of the Catalyst Da-1 Antenna, this is a revolutionary device that combines the high quality but low cost ($350) antenna with the processing power of a smartphone to create a software based receiver and data collector. This is a level of conviennace that enables the receiver to update and upgrade when new signals, algorithms for signal acquisition and tracking and processing are available. This is a much easier to use future proof positioning system which also allows the use to differential positioning techniques to gain higher levels of accuracy.

If a greater level of precision, accuracy and reliability is need in cases of engineering and surveying projects or for regulatory purposes then the PointMan solution can then be paired with higher accuracy level Trimble receivers from the R2 to the R12 and to the construction and earthworks market SPS receivers. This allows a level of flexibility in choosing the proper type of hardware or software receiver for the task, keeping in mind ease of use and budgetary constraints.  The training and familiarity invested in the PointMan solution is not lost and aside from a simple initial configuration in choosing the type of GNSS at the start of the field operation will enables the field operator and project manager to concentrate on collecting the data and not on training or running separate field crews with different expertise levels and software configurations.

It is cost effective to equip many field crews with Catalyst Da-1 antennas and tablets and collect field data and then to equip only a few specialized teams with higher level R Series GNSS units when the need warrants. This also means that companies that have made the investment in higher end Trimble receivers can continue to leverage that investment. Crews trained on the PointMan solution with a Catalyst system will be able to use that knowledge base to seamlessly transition to the R Series when needed.

Trimble SDK Setup in PointMan 

The PointMan solution is used both to configure the type of GNSS positioning system and to collect the field data. Trimble requires an application called Trimble Mobile Manager (TMM) to control the differential correction subscriptions (if used) and to initially setup the GNSS receiver parameters.  This process is usually only an initial process that then will be saved and used in subsequent field operations. This usually means that it will be setup by the field manager on the tablet or data collector at the outset of the project and should not require any changes from that point forward by the field crews.

Trimble Mobile Manager Setup

Trimble Mobile Manager is an app from Trimble for configuring and controlling connections to supported GNSS receivers. Trimble Mobile Manager supports the following GNSS receivers:

  • Trimble Catalyst GNSS positioning service
  • Trimble R Series receivers
  • Spectra Precision Series receivers

If the connected receiver is a Trimble Catalyst DA1 digital antenna, Trimble Mobile Manager is also used to select and use Catalyst monthly or On Demand subscriptions.

To run Trimble Mobile Manager, you will need a Trimble identity. This can be created from the Trimble Mobile Manager launch screen. Tap the Create New Trimble ID link, and follow the instructions.

To sign in, enter the email address and password used for your Trimble Identity account and tap Sign in.

Detailed information on the setup, connection and subscription options for TMM is located at: https://help.trimblegeospatial.com/TMM/App-screens.htm

Once you have signed in, you can connect to the GNSS receiver and use Trimble Mobile Manager offline for up to 30 days. From this point you can access those receivers within the PointMan solution in the same manner as choosing an internal receiver.

Figure 1 – Selection of Internal to Tablet GNSS Receiver

Figure 2 – Selection of High Precision Receiver

Figure 1 shows the selection of the internal to the data collector GPS device, Figure 2 shows the selection of the Trimble R Series receiver, as can be seen the process is seamless and easy to use. The use of Site calibration, Geoid models, and differential corrections and other parameters is the same in both cases and this makes it reliable and easy to use in hectic field conditions. Once the initial setup in the Trimble Mobile Manager is configured by the field manager, the field crews just need to continue using the same parameters.  The configuration is self explanatory and in the event of inadvertent changes, it is easy to trouble shoot and fix most problems in the field.

Figure 3 – Site calibration, Geoid models, Pedigree, differential corrections and other parameters

GNSS Status

THE TMM GNSS status page gives you an indication of the connected GNSS receiver and the positional accuracy, this critical to understand before collecting any data in the field and you need to ensure that these positional accuracy levels are sufficient for your purpose.

If you are using a Trimble Catalyst Da-1 antenna; the GNSS status, numbers of satellites, and the position error estimate is given by:

  • RedNo position, or poor position quality.
  • Yellow: Moderate position quality.
  • Green: Excellent position quality.

 

For the R Series and SPS series receivers, GNSS status icon is blue and indicates the correction services and accuracy.

With no receiver connected, the status indicates Not Connected in grey.

NOTE:  Reference courtesy of Trimble TMM GNSS Status webpage – retrieved June 23, 2020: https://help.trimblegeospatial.com/TMM/App-screens.htm