Terrain following

[MagArrow]

Hi All,
We run magnetic surveys using a mag arrow from geometrics. it is a meter long survey device that weights 1.2kg and is suspended beneath the drone on 5m cables. We have used an Alta-X in the past, but are looking to change to a DJI 400 as the hassle of importation and registering a drone over 25kg in some countries is just too much.

the terrain following capabilities of the M400 are very intriguing, typically we fly at 15-20m above ground, so the sensor is 10-15m above the ground.

Is there a minimum level that the terrain following capabilities of the M400 works? and i assume that at low levels the max speed is reduced, not normally an issue as we fly at 5-10m/s (18-36kph)

I can not see anywhere this information, instruction manual, chat rooms etc.

your hep much appreciated.

regards
AD

 

[jaja6009]

I am not sure of the speed when using terrain following, but I would only use a high resolution DEM. The DEMs from DJI are of lower resolution and dated, at least that's what's been reported from some users.

 

[MagArrow]

Thanks for your comments.
I believe the DJI DEM is just the SRTM data was is a 30m resolution, no where hood enough for us.
The M400 has a forward scanning laser? which constantly assesses the terrain and the drone adjusts its height to the preset ground distance. A DEM is not required which is of particular interest as the sites we fly typically do not have them available. The cost to fly a 20-50km2 area for a DEM is often too much to pass on.