Position update functionality in Integrity Monitor

When the adjustment has resulted in reliable position displacement estimates, these can improve the known positions.

The Integrity Monitor module includes two methods to improve the known point or station coordinates.

Using the Apply Displacements command you can update the point or station coordinates with the last result.
If the parent of the Integrity Monitor module is a GNSS processing engine, the Calculate Coordinates and Velocities command is available. This command includes several variants to calculate the station position at the reference time and / or the velocity of station movement using all results of a specified period.

Tip - Besides detecting the movement of points and stations, the Integrity Monitor module can assist you in finding erroneous point coordinates in the point list, and erroneous station coordinates or antenna heights in the station list. A typical example is an antenna being moved and not reported to the operator.

Applying the current displacements to point and / or station reference coordinates

You can add the current estimated displacement to the known position and thus overwrite the point position in the point list and the station position in the station list. The new positions immediately apply for all modules using point or station positions.

To apply the displacement values to the coordinates of one or all points/stations,

Do one of the following:
- In the Tree view, go to the Integrity Monitor item.
- Go to the Integrity Monitor Current Displacements module view.
Open the shortcut menu and select Apply Displacements.

The Current Displacement Values dialog appears. Use it to view the current displacements for all points and stations that are not held fixed and to select the points or stations for which you want to apply the displacements.

Applying coordinates and velocities calculated from a range of epochs to reference positions

For Integrity Monitor modules below an engine processing GNSS data, you can calculate trends (velocities) and thus estimate the GNSS station coordinates at their reference times. If a station is moving, you can update the station's reference position by applying the calculated coordinates and velocities to selected stations in the station list.

The software calculates for a specified time range a linear regression from the displacement results. The slope of the resulting trend line is equivalent to the velocity of the station’s movement on the tectonic plate; its offset at the reference time can be used to update the station’s reference coordinates.

For information on the reference coordinates and reference time, see the system properties.

Three variants are available as processing types:

Processing type	Description
Velocity and coordinates	Calculates a linear trend with the given data without any restrictions. The position value of the trend line at the reference time determines the reference coordinate. The slope (gradient) of the trend line determines the velocity of displacement.
Velocity with fixed coordinate	Use this selection if you do not want to change the station's reference coordinate, but expect a movement of the station on the tectonic plate. You can use the result to update the Station information, Velocity settings in the three directions for the selected station(s). Calculates a linear trend with this constraint: At the reference time, the trend line passes through the known station coordinates. That means, the reference coordinates are held fixed. The slope (gradient) of the resulting trend line determines the velocity of displacement.
Coordinate only	Use this selection if you are sure that the station does not move on the tectonic plate. The coordinate value is calculated as a mean value with the given data. This can be interpreted as the calculation of a trend line whose slope is constrained to be zero. That is, velocities are not calculated.

Processing type

Description

Velocity and coordinates

Calculates a linear trend with the given data without any restrictions. The position value of the trend line at the reference time determines the reference coordinate. The slope (gradient) of the trend line determines the velocity of displacement.

Velocity with fixed coordinate

Use this selection if you do not want to change the station's reference coordinate, but expect a movement of the station on the tectonic plate. You can use the result to update the Station information, Velocity settings in the three directions for the selected station(s).

Calculates a linear trend with this constraint: At the reference time, the trend line passes through the known station coordinates. That means, the reference coordinates are held fixed. The slope (gradient) of the resulting trend line determines the velocity of displacement.

Coordinate only

Use this selection if you are sure that the station does not move on the tectonic plate.

The coordinate value is calculated as a mean value with the given data. This can be interpreted as the calculation of a trend line whose slope is constrained to be zero. That is, velocities are not calculated.

Note - The quality of the result values substantially depends on the quality of the displacement values generated by the parent processing engine. For applying coordinates and velocities to the known station information, make sure the results of the parent engine are accurate and reliable.
An example where applying the results is contraindicated: A Post Processing Engine calculates relative positions. Thus, it can only provide relative velocities, or coordinate changes relative to a fixed station. That means, the resulting velocities for a station not held fixed are velocities relative to those of a selected fixed station. For the station information, however, we need absolute velocities.

To calculate coordinates and velocities for GNSS stations and to apply them to selected stations, do the following:

In the Tree view, go to the Integrity Monitor item.
Open the shortcut menu and select Calculate Coordinates and Velocities.
The Calculate Coordinates dialog appears. Use it to select the period used for estimation, the processing type and stations for which you want to perform calculations, and to start the processing.
After successful processing, the Apply Coordinate Values dialog appears. Use it to select the stations to which the new coordinates and velocities will be applied to.