The MinGrazingAlt property applies to space based tracking where one satellite produces measurements of another satellite. Enter a minimum grazing altitude constraint on the TrackingInstrument sub-object of the tracking satellite. This constraint is used by the simulator and filter - no measurements are processed (by the filter) or generated (by the simulator) at a given time if the calculated grazing altitude between this satellite and the target satellite is less than the constraint value. This constraint is not applied to ground based observations to satellites in orbit about central bodies other than the Earth.
There are two special cases where the MinGrazingAlt setting from a satellite object is used. The MinGrazingAlt setting from the relay satellite is used for computing visibility for 4L Range, 5L Doppler and 3L Doppler where the signal path connects a user satellite to a ground station through the relay. In this case, the MinGrazingAlt setting on the relay is used to constrain the link between the user satellite and the relay. The second special case is 2L CA Pseudorange where a signal emanating from a GNSS satellite is passed through a user satellite transponder to a ground station. In this case, the MinGrazingAlt setting on the user satellite is used to constrain the link between the user satellite and the GNSS satellite.
