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GNSS Receiver Multipath view

The plot on the Multipath Plot view displays the multipath for given elevation and azimuth in colors from green (zero multipath) over yellow to red (high multipath). Multipath plots are available for GPS satellites only.

The plot is North-orientated: The upward vertical axis points to North. Center of the circles is the zenith (elevation angle 90°) and the outer circle shows elevation 0° (the horizon).

This plot is generated from the MPT files stored in \<installation folder> \ Container \ Multipath. The contents of these files are updated as long as the station configuration is known to the system and remains unchanged and, therefore, contain information from several days. If you change the station configuration (for example providing new station coordinates or if the hardware is replaced), Trimble 4D Control Server recomputes the multipath and deletes the previous MPT file.

Additionally, the blue line in the polar plot visualizes default and azimuth-dependent elevation cutoffs that one specifies using the module's Azimuth dependent cutoff property.

Use the plot to detect obstructions.

Select multipath type, selection field

Specifies the phase and code combination, for which the signal errors are currently displayed in the plot. Trimble 4D Control Server supports the following combinations. The available selection, however, depends on which combination the selected receiver type can track theoretically.

If the specific receiver to which this GNSS Receiver module refers is configured to track less combinations, the code and phase combination for a selected multipath type may not be available. In this case, the plot is empty, and the Maximum Multipath field displays "No data".

The code multipath is derived from the code and phase measurements (actually the code-phase combination is used), a very common approach. In case of phase multipath the module uses the Signal-to-Noise Ratio measurements which the receiver outputs for each signal (for example, L1 C/A, L1 P). Therefore, the view displays phase multipath plots for each signal type separately.

Legend

The legend gives the signal errors for different colors.

Numerical values

The maximum value displayed below the plot refers to the selected phase or code combination. For all available phase or code combinations, the moving averages of the global multipath RMS values are displayed at the right side of the view.

Use the numbers for a first glimpse comparison of a selected multipath error on several stations. Thus you can get quickly an impression of the multipath qualities at these stations.

Elevation cutoff in the skyplot

The blue solid line indicates the current elevation mask setting. If the blue line does not appear in form of a pure circle, the divergences from the circle depend on the settings of the module's Azimuth dependent cutoff property.

Properties of the view

For the Multipath view, additional properties exist.

The Multipath Properties appear if you right-click anywhere into the plot area and select the Properties shortcut menu command. One of the following happens:

Use the Multipath Properties category to view and edit settings specifically applying to the Multipath view.

See Also

Raw data analysis

Multipath Properties

GNSS Receiver

GNSS Receiver Properties - Receiver Data

Azimuth Dependent Elevation Cutoff dialog