# Create a capture over a steep slope

Hi all.

I got an interesting telephone call earlier today. The call was from a company who’s owning/running a ski resort in my home town See https://www.google.com/maps/place/67°06’09.7"N+20°37’39.7"E/@67.1025668,20.6263372,670m/data=!3m1!1e3!4m14!1m7!3m6!1s0x45d71c45e0c11709:0x2fcc4f970c0f9c2!2sDundret!3b1!8m2!3d67.0833333!4d20.5166668!3m5!1s0x0:0x0!7e2!8m2!3d67.1026921!4d20.6276887!5m1!1e4

Due to the Corona Hysteria everything has been closed since easter, and the man who contacted had a couple of questions to me regarding to get an Orthomap and a 3D of the slopes and use them in his marketing. He also wants to monitor the snow melting to get some knowledge on how the snow is melting and WHERE it melts first to be able to create a mountain bike trail asap to make some money.
The slopes are some 1,3 – 2,5 kilometers in length dropping some 300-400 meters during this distance. The highest begins at 823 meters above sea level. There are steep slopes an plateaus in a chaotic mixture as nature tends to be.

I can access the slopes in question by foot and create a capture and do the thing. But how does my P4P 2.0 act when I set the capturing height to 100 meters and begin my capture? Does the P4P keep the height when moving downhill (keeping the height by itself) or do I have to “cut” the slope in, say 4 – 5 captures and the use ALL images to do the Orto (and 3D).

Do I do the capture downhill or 90 degrees? Does it make any difference?

The key question is: Does my P4P Keep the height when moving downhill or does this take another type of drone/system? RTK?

Tried to do some searching on the net, but cannot find anything of interest. Surely this must have been done before, I think. Ifound a thread here from 2018, but this was f no help. I know there is a terrain awareness gizmo in the DJII app, but does this work using DD:s app for capturing? I’m using Android.

I’m thinking about to do this pro bono to help the poor company owner out in these miserable and difficult times.

Any hints, tips advices and tricks would be appreciated.

Rgds Roger

Terrain Awareness on running parallel with the slope is your best bet. Make sure to measure some of the tallest trees and go 30-40ft above that to ground.

Excellent news. Haha… I’ve seen this tiny icon, but never actually SEEN it.
I made some off-line tests, and… well… Can this be trusted upon?

I made this. It’s on a slope completely deforrested. Capturing altitude set to 45 meters (The app suggested “below 40 meters”).

What are the blues and greens telling me?

When I click the blue icon (beside the “Flight altitude” I’m getting this:

I can assure you that the slope is not jerking up and down with some 75 meters for 600 meters in distance every 200 meters… I’ve been running on these slopes for years now. I’m also raising questions about the spot labelled “Highest”. Actually the slope continues upwards rather evenly. No dips or bumps.

Suggestions on front/side overlap?

What am I doing wrong? Can’t this be done like this?

R

It seems as if the maps I have to work with in Sweden doesn’t contain the information needed for “Terrai awareness”. I made another test, and this returns the same lack of awareness…

@Jamespipe, could you please take a look into this one?

Looks like there is a serious issue with the terrain model in that area. Please may you share the link to your project to help me investigate?

We will take some time to investigate this but do not fly this plan as shown! Disable terrain awareness and fly from the top of the hill, in sections.

James

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That is a link using your login and noone will be able to access your flight console. You might try to PM James the flight ID.

It seems as if we have a case of misunderstanding here due to my language skills.
I have no map, and therefore no map ID to sen. I made a planning in order to do the capture, but wouldn’t dare to trust on the terrain awareness when I saw how the “awareness” seems to work during the planning.
And hence my querstion: “Can this be trusted on”?

So. The flight hasn’t been done yet. Only planned…

Hi @KRWaara - Based on this terrain awareness plan, there is very limited terrain data available at your location. We would not rely upon this. Until this is resolved, please only fly at altitudes above the height of the highest obstruction from the takeoff point.

The link you shared is sufficient for us to investigate. Thank you for sharing and for your patience.

Gotcha, I saw the link and thought there was a map already when it was actually just the URL to the flight plan as I mentioned.

That model is definitely bad. Here is the Google Earth SRTM. I had trouble seeing the exact flight area as the maps are different, but if I’m close then it will not change that much. I’m not sure why this isn’t available in DroneDeploy’s surface.

I’ve started to split the areas up, and do them in separate sessions due to the Terrain Awareness not working.

See example1:

And Example 2…

Are there any rules of thumb? How do I think when I split them? Never done this before…

Gee. I hope DD can fix this Terrain awareness in my region asap. But i read somewhere that TA is not available for captures over a certain area…

R

R

For just \$25 Litchi is probably the best software you can purchase for DJI drone flight. It is not meant for mapping, but it is so granular in the depth of the settings the you can fly pretty much any way you can imagine. I have done maps with it and while the setup takes a little longer the plan is done at the end and I don’t have to recreate it. You can plan on Google Earth, a website for on the mobile device. I would design the flight with DroneDeploy at the AGL and overlaps that you want and then mimic the spacing of the lanes. A 3D KML from Google Earth or if you have other means of software for creating a KML can be imported into Litchi.

Alternatively you can look at Drone Harmony. They claim terrain-following, but I don’t know if the models are any different. Drones Made Easy Map Pilot is the only other one that I know of with terrain-following, but it is for iOS.

I’ve heard so many rumours regarding Litchi, how bad it works and so on. I have been in contact with Maps Made Easy, but I find their customer support rude, to be honest. I like the service, but the people working there are not customer oriented at all.And I’m using Android, which disqualifies them.
I think I’ll have to try Drone Harmony.

Do you have a link I can use to learn more on how to split a mission into several due to changing height? I’m planning my flight at maximum height, 120 meters, but if the terraing drops 75 meters during the capture I understand I must do something. The P4P just continues at its height not giving a rotten blueberry on what’s happening with the ground.
So sad that Dronedeploy failed me. I like the app. I also like their post processing capabilities. The only thing i’m nor fond of is the pricing model, which ultimately is going to kick me off to MAps Made Easy, rude support or not.

Just noticed that Map Pilot can deliver Terrain awareness if I’m between 60° north and 56° south latitude. My home town is slightly above 67° north… :(. So even if I had a iOS - device and the customer support was polite I wouldn’t be able to use it…

Drone Harmony looks nice. The only problem is that I have to find a local ESRI ASCII Grid to use for the awareness. The Swedish mapping authorities has this, but costs a fortune to buy…

So much looking forward to a solution from Dronedeploy…

R

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Hey @KRWaara, good morning from Texas! I know Terrain Awareness (Following) is a hot topic across many drone use cases so thanks for the experience report.

It’s a big world we all are living in, I can tell…

I’m kind of lost at the moment regarding this pro bono gig I had planned to do. Sad that the actors can’t help me with the Tearrain awareness. Well, Drone Harmony are claiming this, but the ESRI ASCII Grid seems too expensive for my humble company…
Let’s hope that the brains on Dronedeploy will be able to solve this problem with the maps…

However: I appreciate your support a lot!

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I have been flying in the hills of Vermont,USA and the last time I tried to use the terrain awareness it did not work. I have been using Drone Deploy now for about four years and everytime I make a map I have to climb to the highest point and launch from there if possible. This has been a big problem for me from the start but this is the only reliable way I have been able to capture good photos.
When I tried to use the terrain awareness app it did not make any differance and if I had not been watching closely it would have crashed into the top of the trees.

@skyviewvt. Not nice to hear. This might never been working. I’m so disappointed at this fact that they are promising a fuction which is not working. Ad if it only works in parts of the world: Then let us know…

R

I think this is the key and honestly not surprising. Surfaces are a tricky thing and you need to validate that even though there is a surface available that it is accurate enough. This will take a little time to find those specific areas so keep the feedback coming and we will knock it out much faster. Luckily in my area it has always worked even through beta, but I experienced the same thing even with bringing Google Earth surfaces into our design software. It just tells us that they don’t have data available in that area when there is obviously terrain like the profile I posted above of your site.

I think this points at the accuracy factor and what the provider deems sufficient for the use-case because in our software we can get down to a 5 meter resolution in some areas when normal Google Earth is 10 meter.