GNSSReceiver Object

GNSS Receiver: Measurement Processing

The following measurement processing parameters can be set for a GNSSReceiver object:

Measurement Processing
Parameter Description
TrackingID The receiver ID. Must match the "Marker Number" for the associated RINEX Observation file.
NumberOfChannels Used by the simulator to control the number of GNSS measurements generated at any measurement time. The NumberOfChannels is the number of satellites that can be tracked for each basic type of measurement statistics (i.e., CA, P1 and/or P2) with which the GNSSReceiver is set up. For example, if the GNSSReceiver is set up with CA, P1 and P2 measurement statistics, and NumberOfChannels is set to 8, then the simulator can simultaneously simulate CA, P1 and P2 measurements for 8 satellites.
MinGrazingAlt The minimum grazing altitude for editing out GNSS measurements. (Available for Space type GNSSReceiver only.)

The minimum SNR needed to accept a GNSS measurement for processing. Used only if the S1 parameter or SSI flags are output in the RINEX Observation file. If the SSI flags are output, ODTK maps the SSI flag value to SNR as follows:

  • 9: SNR > 500
  • 8: SNR > 100
  • 7: SNR > 50
  • 6: SNR > 10
  • 5: SNR > 5
  • 4: SNR > 3
  • 3: SNR > 1
  • 2: SNR = 0
  • 1: SNR is bad
  • 0: n/a



Set the following attributes:

  • Method  - Choose between performing satellite selection based on minimizing GDOP (BestNGDOP) or using a custom algorithm via a plugin. See help on ODTK plugins for information on how to create and register a GNSS Satellite Selection Plugin.
  • PluginID - Available if Method is set to Plugin. Select desired custom algorithm from a list of registered plugins.
  • PluginConfig - Available if Method is set to Plugin. Provides access to configurable parameters as registered by the plugin.
  • RetainLast - If set to true, then the same N GNSS satellites are used from one time to the next so long as all N are still visible. When all N are no longer visible, the best N new GNSS satellites are determined on the basis of the specified satellite selection method.
MaxPhaseRangeGapTime The maximum time allowed between accepted phase range measurements without reinitializing the initial range estimate. The initial range estimate is the range at the beginning of the contiguous count interval.

Note: During simulation of GNSS measurements, if a GNSS satellite selection plugin is being used, but fails, the simulator will continue with a default selection which simply picks the first 4 satellites. When using a GNSS selection plugin to simulate measurements, check the message viewer carefully for plugin failure messages.

ODTK 6.5