I really can’t fathom this one out…I set up a simple mission using Litchi Hub, all waypoints were set to an altitude of 14 feet above take off point, yet when I load the same mission into the Litchi app the waypoints altitude is showing as 13 feet, when I try to adjust this height in the app screen I see that the + increases it to 17 Feet and the - decreases it to 10 feet….it was worse when I selected AGL in the Hub , as the altitudes were all over the place when in the Litchi app, and my drone smacked into a goalpost which was supposed to be below the height I had entered to that waypoint……..really scratching my head of very little hair that I have left…..
Hi Doogieman. I’ll Try to help but there is a lot of things with a mission like this at a very low altitude which can make it difficult to work perfectly. First regarding when using AGL. The drone will fly at roughly the set altitude but the all the waypoints altitudes will indicate the altitude based on ATL, above take-off location. So the drones altitude in the app will indicate differently as they are displaying altitude based on the take-off location, not the above ground at each waypoint. There may be at a a plus or minus value of the set AGL altitude. So that’s more than likely why you see the waypoints altitudes all over the place using AGL. All of these drones have no way of measuring actual above ground altitudes. Also the inaccuracy of these consumer drones can be off anywhere from + or - 4m, roughly 13’. They may not be off that much but I’ve found on one AGL mission to get the drone to fly at an actual 6’ altitude above ground the plans altitude needed to be set to 12’, so that’s a 6’ inaccuracy. The only way to get much more precise accuracy is to use a drone with RTK. As far as changing the altitude in the Mobile app it does not have the ability to enter the altitude manually and using the plus and minus has always been this way where it jumps several feet or more. I can confirm if I set the altitude to 14’ in the Web app it does indicate 13’ so not sure if Litchi can fix this or not. Even if it was set to 14’ I’m not sure it would change much in the way it flys due to the fore mentioned inaccuracies. It just will not fly any mission with that type of accuracy.
Does a DJI drone with RTK use RTK for for height or do they still use barometric pressure to determine height like all other DJI drones? I have only ever heard that DJI drones with RTK used it for horizontal positioning but I could be wrong.
cheers Mike…..all makes sense…. I’ll try doing a waypoint mission using the GO 4 app and see if that has the same altitude problems…. a tad wary now of using the software..as I nearly lost my old MP2 dinosaur….. 
, Davy
MP2 uses barometric pressure sensor
Yes, as far as I know, all DJI drones use barometric pressure to determine height above take-off. My question is if RTK modifies that.
DJI drones only understand meters, so when using feet, there is a conversion that happens to meters internally. Due to rounding errors this may lead to small variations regarding what is displayed in the app, however the value sent to the drone should be the same, as that is always in meters.
For what it’s worth, using Mini 4 Pro, if I set to 14ft in Litchi Hub, it shows as 14ft in Litchi Pilot.
Older apps may round differently when displaying the altitude which might cause small discrepancies but internally the altitude is what you set in Litchi Hub
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cheers, I am using the latest version of Litchi Pilot.. is changed altitudes to meters and it has kept the same heights from Litchi Hub to Litchi Pilot… me, being oldskool had to use Google to convert imperial to metric…..LOL… will give the test waypoint a wee test later…. many thanks for the clarification as to the altitude discrepancy……
wee update…created a simple waypoint mission, Litchi and drone performed flawlessly…. 