Processing total station and GNSS data using the Integrated Survey Engine

The Integrated Survey Engine is one of the Trimble 4D Control Server core processing modules. It is used to process different data types in an integrated approach:

• The optical raw measurements of a total station mission provided by one or several Data Collector modules in a real-time system.
• GNSS baseline data pre-processed by the whole variety of GNSS processing engines.

Integrated Survey Engine computes target point and station coordinates in the GNSS reference frame. The stored data can then be used by:

• the Integrity Monitor modules to compute positions in the global reference frame, to display a map and the differences between reference and later measurements over time (local displacements dN, dE, dH),
• the Alarm Manager module to create Alarms depending on predefined thresholds,
• the Trimble Report Generator to generate editable and printable output.

Similar to the Terrestrial Engine RT module it uses the optical real-time measurements provided by one or several Data Collector modules, which all pertain to the same mission.

Adding the module

The Integrated Survey Engine module is available from the Tree view root Trimble 4D Control Server. Trimble 4D Control Server accepts multiple Integrated Survey Engine modules in the system.

When the module is being added, the Integrated Survey Engine Properties dialog appears. It lets you define and select module configurations. Each configuration holds information on the data sources and their processing settings. You may remove a configuration from here, if you do not need it anymore. You may change the settings of the selected Integrated Survey Engine configuration at any time.

Data sources and processing

The Integrated Survey Engine module uses the optical raw measurements provided by one or several Data Collector modules together with pre-processed GNSS baseline results from one particular GNSS processing engine.

The GNSS processing result will be used to define the global reference for the total station site setup. In order to fulfill this requirement all total stations need to observe at least two common points (two combined GNSS and optical backsight points or one GNSS backsight and one GNSS station above the total station).

Each Data Collector module contains one total station site setup based on common points (GNSS and/or optical only) and the round measurements to the monitored target points. The Integrated Survey Engine module can combine the round measurements of all selected Data Collector modules of a mission in a synchronized data processing. Additionally, it applies current air pressure and temperature values to correct the data.

From the GNSS station coordinates and the corrected measurements of the targets the Integrated Survey Engine computes positions for the unknown points.

Output of results

The Integrated Survey Engine makes the results of its estimation process available to depending Integrity Monitor modules.

Note - You need the adjustment functionality of the Integrity Monitor module for processing positions of the unfixed points and for updating point entries in the global point list. The Integrity Monitor module is also used to display the offsets between the reference coordinates of a point and its positions in following rounds in numerical and graphical form. The resulting positions and maps refer to the adjusted and possibly rotated coordinates.

The synchronization status and history of the round measurement and the GNSS processing results are displayed at the Integrated Survey Engine views.

Alarming

With alarming activated, the Integrated Survey Engine module triggers alarms, if the following happens (In combination with the Integrity Monitor module, additional alarms can be triggered if displacements exceed specified thresholds):

• Point not computed
• Meteorologic sensor data missing

Logging into the database

The Integrated Survey Engine module writes the synchronization status into the central database. The database contains the following table referring to the Integrated Survey Engine system: