Why is there such an altitude difference between programmed and actual?
I used the “verify height” selection on the initial programming.
Even the logs reported I flew no lower than 100 feet above home but video evidence shows differently.
Especially the 4th spline waypoint where I almost hit some trees because I was much lower than 100 feet.
I use to fly Spline navigation (Navio2 with 3.4.3 or VRBrain 5.2 with 3.3.3) without experiencing your problem.
I use Tower (Android) for planning, logic is not the same. You may have a try if you have some android device available.
You could also try to have more waypoints along the differents legs of your flight plan. If the glitch is memory related, having shorter legs could help.
Usually due to discrepancies in Google’s terrain elevation data. I’ve seen discrepancies of 40-50 feet vs actual survey data supplied by USGS. Combine that with pressure changes due to atmospheric conditions and wind on slopes or terrain features, and its effect on the barometric altimeter, and you can easily fly an aircraft into the ground.
When planning survey flights where the aircraft must fly at a specific height above terrain I ALWAYS use the ArcGIS elevation model from the survey done by USGS, calculate the waypoint altitude myself, and never use Google’s estimation of terrain elevation. Google’s stuff might be “good enough” for the average consumer. But it’s not good enough to fly an aircraft with. If you read Google’s licensing terms on their supplied data, that is clearly stated.
