How do I aerial survey woodland?

[Malcx]

With rules changing in the UK around commercial work later this year, I've a couple of contacts who are landowners asking about doing some straightforward mapping of their land (mainly to get a record of bracken coverage and the like)

One of the areas is flat woodland with no hills or structures nearby that I could use as a launch/lookout point.

I could quite easily launch from a clearing, let the Mavic do it's thing following a set course and return, but once airborne and say 20m away my LOS will be obscured by trees.

The question is how would a pro survey this type of land while keeping VLOS or would it only be possible under elevated permissions from the CAA?

 

[Marty Markoe]

As the DJI Mavic 2 Pro and others have great range, are you able to find a clear spot where you will have a visual line of sight? You can also program Waypoints to automate the process.

 

[G Saunders]

If you're trying to do anything like a map or survey a mapping app and engine like DroneDeploy.com might be what you need? It would fly a grid over the site, bring back lots of overlapping images, then you upload them to DroneDeploy and it applies orthogonal correction and stitches them together to make a big 'map'.

I put 'map' in quotes because it takes a surveyor to make an official map.

If you fly the mission high enough, maybe you can find a spot where you can keep the drone in VLOS? I've got a cul de sac in a heavily wooded neighborhood where I can see my drone out to a thousand yards if I keep it at 350+ feet...

 

[Tkoglin]

I can see my drone out to a thousand yards if I keep it at 350+ feet...

wish I could see my drone and it’s orientation 3,000ft away

 

[Malcx]

Thanks for the responses.
The "mapping" itself isn't an issue, I use an MP1 with Dronelink to plan the mission and capture the data.
WebODM then processes it nicely into GeoTiff files. I've done several missions like this around my local area for fun and as a freebie for a friend.

The problem is how would it be possible to fly a mission over a flat area of land that is covered in trees. The nearest hill of any note is about 1km away from the near edge of the area I need to map, so I'd need to be able to have VLOS at maybe 1.4km. I've good eyesight, but not that good.

I know the drone comfortably has the range, I just wonder how professionals would do a job like this while maintaining VLOS?

FWIW - It's not a million miles from Gatwick airport so I'd want to be very sure I'm complying with all regs!

 

[Keule]

so I'd want to be very sure I'm complying with all regs!

If VLOS can't be established all the times, then you have the following options:

- Do not fly at all
- Fly without VLOS (illegal as you already mentioned)
- get the appropriate waiver for BVLOS

If you are doing it commercially, I strongly advise getting the BVLOS waiver. (I have no information on what the requirements are in the UK to get such a paper)

 

[Malcx]

@Keule Thanks - That actually kinda distills it down for me to what should have been obvious options. (sometimes it takes another to point out simplicity ?)

For the location, and from what I've read, I think getting a waiver will be too much effort for the payoff so I'll most likely turn this job down.

 

[G Saunders]

wish I could see my drone and it’s orientation 3,000ft away

I can see an Inspire out that far with the sun behind me, have 20/5 vision in 'rebuilt' eyes with good glasses. I used to have 20/10 and now they're better. Following a year or so of increasing blindness from a severe allergic reaction to IV meds that blew off the fronts of my retinas it was amazing how well they got fixed over the next year. I now have no pre-retinal membrane, new vitreous, no posterior capsule wall, and Bausch and Lomb made better lenses than the ones I grew.

I can't see a Mavic past a thousand feet or so, or a Mini much past 400...

 

[Keule]

@Keule Thanks - That actually kinda distills it down for me to what should have been obvious options. (sometimes it takes another to point out simplicity ?)

For the location, and from what I've read, I think getting a waiver will be too much effort for the payoff so I'll most likely turn this job down.

Nevertheless, I would try myself to get all the information on the requirements to get BVLOS waiver. As you know from July 1st, 2020, there will be new rules in effect to determine the risk assessment of the operation. Aircraft classification (C0 - C4) area of operation and so forth. Don't forget the charges that apply.

Be one of the 'first' to take the chance and be prepared for the future.

Good luck.

 

[G Saunders]

WebODM then processes it nicely into GeoTiff files. I've done several missions like this around my local area for fun and as a freebie for a friend.

How's your experience with WebODM? What are you running it on? I've thought several times I'd like to put together a server with it and ditch DroneDeploy...

 

[Malcx]

Nevertheless, I would try myself to get all the information on the requirements to get BVLOS waiver. As you know from July 1st, 2020, there will be new rules in effect to determine the risk assessment of the operation. Aircraft classification (C0 - C4) area of operation and so forth.

It's the new rules that I'm planning on doing this under. Operationally it's private land with no immediate hazards, buildings or people other than maybe a dog walker or two - so as far as I understand from the new rules if I maintain VLOS and am using a Mavic Pro 1 then I'll be fine doing the other jobs under the "low risk" category and not need additional authorization.

To get a waiver for beyond VLOS I suspect I'll need to do the equivilant of the PfCO first which makes it not financially attractive unless I was going to build a proper business out of this.

Don't forget the charges that apply.

Obviously I have done the new operator and drone registration and paid the £10 or whatever it was - are there other charges that apply that you're aware of?

Thanks again!

 

[Malcx]

How's your experience with WebODM? What are you running it on? I've thought several times I'd like to put together a server with it and ditch DroneDeploy...

I'm running it on a mid-high end gaming PC that was bought 5 years ago. It's not super fast and takes maybe 1-2 hours to stitch together 350 images covering an area about 270000m2 (500m x 500m)

The results are pretty good for creating the GeoTiffs, I've not needed 3D output for anything and after my quick tests with it I would say DroneDeploy gives better results on that.

It is free, although I was having issues installing it due to various other conflicting development environments I have already on this machine, so I paid for the installer and spent a weekend emailing with one of the devs to debug the issues and get it installed finally!

Have a play with some of their free credit offering on a small test project and see if it works for you. Long term for my needs it is much cheaper than DD

 

[Hopper13]

wish I could see my drone and it’s orientation 3,000ft away

haha... me too, but I believe that there is a difference in meaning between the words “in sight” and ”visual line of sight”. Just my .02. Your battery life may vary... ;-)