Part 107 UAS pilot reported flying in excess of 400 feet AGL due to a programming issue. The deviation was noticed and the flight was ended immediately.

Narrative

During loiter; aircraft began to climb above altitude set in the mission waypoints and above part 107 400 ft. AGL limits. Using alternative descent methods; the aircraft was immediately landed to determine the cause for the deviation. After review of the aircraft flight plan; it was determined that the Ground Control Station (GCS) origin was set at a different location than the actual GCS location. This resulted in the aircraft attempting to climb to maintain 'artificial' Line-of-sight (LOS) with the incorrect GCS location (due to automated preselected settings). This could have been prevented with a more in depth understanding of the system and additional review of the operations publications. The system provides the user with simulated outcome of the mission plan prior to takeoff; and indicates if LOS will be maintained (but does not prevent the user from performing the mission). Additionally; certain selections can be made to prevent the aircraft from climbing to maintain LOS. However; the system does not provide user notification that it is off mission altitude and climbing for LOS altitude. The system has min/max altitude restrictions but during this LOS scenario; it disregards the max altitude to attempt to regain LOS.