Sudden Vertical Shifts/Jumps

Symptoms : The elevations may suddenly and randomly jump (0.3 to 4m / 1 to 10ft), requiring going back and re-zeroing. This occurs at various times (minute to hours apart), but not predictably. RTK fix is sometimes dropped, but regained in 1-3 seconds, however, the elevations do not return to the original values. For smaller shifts in elevation, see Vertical Performance Issues (GPS drift) . When investigating in detail: In the GPS logs, these jumps only occur at the start of a new second when an RTK correction is applied.   Possible Cause : Base receiver has an intermittent failure. Solutions : Update the receiver software of the base and rover. Swap the base receiver with a working receiver.