Hi everyone,
I need your help to achieve in the best way possible a simple corridor mapping with changing elevation.
With my old but gold Phantom4PRO with MapsMadeEasy app, i simply download the DTM for corridor mapping and the drone keeps constant elevation to the ground.
I can't figure out why DJI in Pilot app doesn't have the terrain follow function in corridor mapping, but only in the area mapping. WHY DJI? WHYYYY?
I have to survey a 23km x 30m path, mix with P1 and L1 (L1 in woods area), and with P1 i'd like to make a 2/3 parallel paths, with L1 just one for only 30/40m width.
In some areas, the elevation change is pretty important, with 150m changing in elevation, in most of the path the difference in elevation is about 30/40m per km.

Which is the easiest way to achieve a corridor scanning without using corridor mapping function?
(i haven't checked yet, in Pilot2 app DTM for corridor mapping is usable? in Pilot1 wasn't).
Do i have to use waypoint?

Thank you

You could make a lot of long skinny area map missions, no?. Inefficient, but if you're trying to stay in VLOS it might be safer anyway (not sure what the rules are in Italy).
But yes, I feel your pain. It's almost like DJI decides what functionality a new system or software will have by using a grab bag of features- they pull a few out each time, which may or may not be the same as previous, existing systems or what is available on other platforms and considered industry-standard.

That will be my last chance... But the road i need to survey is not so straight, so i need to make a lot of mission if i want to follow this path. I think i'll use waypoints mission with timed interval shot of P1. For each waypoints i'll set the altitude comparing it on google earth.My missions will be only VLOS, our regulation allow 500m horizontally from take off point, so i'm going to survey 1km per flight (+500-500m).  
Shame on DJI for this missing feature. I used the Phanotom4 for 6 years (now retired), and this feature existed since 2017 in third part app.

Panph Posted at 6-7 03:06
That will be my last chance... But the road i need to survey is not so straight, so i need to make a lot of mission if i want to follow this path. I think i'll use waypoints mission with timed interval shot of P1. For each waypoints i'll set the altitude comparing it on google earth.My missions will be only VLOS, our regulation allow 500m horizontally from take off point, so i'm going to survey 1km per flight (+500-500m).  
Shame on DJI for this missing feature. I used the Phanotom4 for 6 years (now retired), and this feature existed since 2017 in third part app.

Is Italy not following the "new" EU regulation from EASA? Specific VLOS is depending on UAV, so M300 can be easy flown further than 500m.

You could create a thin/long mapping area as a work around. If your road has lots of direction changes  you might have to break it down into smaller mission areas to minimize turns since it wants to fly everything in the same azimuth/direction. The other solution would be to change the corridor segment length and reference google earth to figure out your limits. You can fly individual segments at a time, you just need to change your altitude and target surface depending where you takeoff for each one.

It's a bit of a headache, but I agree terrain following for corridors would be a welcome feature. Pilot 2 does not have this feature currently, I did a corridor mission yesterday using the methods above.