I might be a little slow on the uptake, but after several readings of the manual I still could not get my arms around how the RTH At Current Altitude setting in GO4 affects things. What I found in the Spark pilot's forum was the following explanation which cleared things up. I do hope it is correct:
NOTE after comparing the altitudes in the following which are from the Spark manual to the M2 manual altitudes, there are some slight differences. But the principles remain the same.
Two settings in DJI GO 4 app are relevant for how RTH behaves after being triggered
- Setting #1: The “Return-To-Home Altitude” setting, i.e. pre-set RTH altitude
- Setting #2: The “RTH at Current Altitude” option
Once the RTH is triggered there are four cases dependant on the drone's distance to the recorded home point to consider.
Case #1 - The drone's distance to the recorded home point is less than 3m
In this case the drone will descend to land immediately from its current altitude and position.
Note: The Current Altitude option is ignored in this case. The drone will not ascend to the pre-set altitude even if the Current Altitude option is disabled.
Case #2 - The drone's distance to the recorded home point is between 3m and 20m with the Current Altitude option disabled.
The drone will immediately descend to land from its current altitude and position.
Case #3 - The drone's distance to the recorded home point is between 3m and 20m with the Current Altitude option enabled
The drone will check its altitude. If its current altitude is above 2.5m the drone will RTH at its current altitude immediately. If the altitude is less than 2.5m it will ascend to 2.5m first and then start to RTH.
Case #4 - The drone's distance to the recorded home point is greater than 20m
The drone will check its current altitude. If the drone is higher than the pre-set altitude it will start to RTH at the current altitude immediately. If it is lower than the pre-set altitude it will ascend to the pre-set altitude first before starting to RTH.
Note: The Current Altitude option is ignored in this case. The drone will always return at the pre-set altitude at a minimum.
Conclusion: The Current Altitude option setting is only taken in account in a scenario where the drone's distance to the recorded home point is in the 3m to 20m bracket. In all other cases the Current Altitude option setting is disregarded. It is perfectly safe to enable the Current Altitude option to avoid immediate landing in case of an RTH event in the 3m to 20m range. If the drone is further out it always returns at the pre-set altitude at a minimum.
NOTE after comparing the altitudes in the following which are from the Spark manual to the M2 manual altitudes, there are some slight differences. But the principles remain the same.
Two settings in DJI GO 4 app are relevant for how RTH behaves after being triggered
- Setting #1: The “Return-To-Home Altitude” setting, i.e. pre-set RTH altitude
- Setting #2: The “RTH at Current Altitude” option
Once the RTH is triggered there are four cases dependant on the drone's distance to the recorded home point to consider.
Case #1 - The drone's distance to the recorded home point is less than 3m
In this case the drone will descend to land immediately from its current altitude and position.
Note: The Current Altitude option is ignored in this case. The drone will not ascend to the pre-set altitude even if the Current Altitude option is disabled.
Case #2 - The drone's distance to the recorded home point is between 3m and 20m with the Current Altitude option disabled.
The drone will immediately descend to land from its current altitude and position.
Case #3 - The drone's distance to the recorded home point is between 3m and 20m with the Current Altitude option enabled
The drone will check its altitude. If its current altitude is above 2.5m the drone will RTH at its current altitude immediately. If the altitude is less than 2.5m it will ascend to 2.5m first and then start to RTH.
Case #4 - The drone's distance to the recorded home point is greater than 20m
The drone will check its current altitude. If the drone is higher than the pre-set altitude it will start to RTH at the current altitude immediately. If it is lower than the pre-set altitude it will ascend to the pre-set altitude first before starting to RTH.
Note: The Current Altitude option is ignored in this case. The drone will always return at the pre-set altitude at a minimum.
Conclusion: The Current Altitude option setting is only taken in account in a scenario where the drone's distance to the recorded home point is in the 3m to 20m bracket. In all other cases the Current Altitude option setting is disregarded. It is perfectly safe to enable the Current Altitude option to avoid immediate landing in case of an RTH event in the 3m to 20m range. If the drone is further out it always returns at the pre-set altitude at a minimum.
Last edited: