Probe results - possible results from a probe query.
|xplm_ProbeHitTerrain||"0"||The probe hit terrain and returned valid values.|
|xplm_ProbeError||"1"||An error in the API call. Either the probe struct size is bad, or the probe is invalid or the type is mismatched for the specific query call.|
|xplm_ProbeMissed||"2"||The probe call succeeded but there is no terrain under this point (perhaps it is off the side of the planet?)|