Will a drone do this

[WildDog]

HI, newbie here with a question regarding the capabilities of drones. I may have an unreasonable expectation of what a drone is capable of doing so I thought id ask here first as I know very little about them

I'm wanting to view the ground and see what type of rocks/soil conditions are present in the bush.

To do this the drone will need to fly reasonable close to the ground (6 foot) and be able to fly around trees. I would like to have a pre-planned flight path and have the drone fly the mission automatically.
I then want to be able to view the video/data on a computer at home and when I see an area of interest be able to know the GPS coordinates of that spot. At the moment I'm walking miles on foot and covering little ground.

That was my ideal scenario, the other option would be to fly it manually but that's going to take a lot longer and I want to cover as much ground as possible.

Any advice on a DJI model that might do all this?

 

[stberlin]

drones cannot do this for you. maybe in 15 years! you want a drone to fly like a hummingbird: hover, survey and navigate hundreds plant and tree branches. in sci-fi movies, yes.

 

[Deleted member 94047]

The two major problems I see with your intended use case are these:
Navigate around trees - NO; some drones have obstacle detection and avoidance but you can't expect this to function as a fully independent auto-navigation.
Fly close to the ground (6 foot) - NO. Well you can, but at that height you are asking for trouble. You will have to set the height a little higher.

Other than those two, you can have the drone do what you want via way-point missions. I have a friend who uses a phantom 4 Pro to monitor crop health. Flies a predefined grid, takes hundreds of pictures at set intervals; stitches them together later, combines the whole thing with satellite imagery. Pretty impressive what he does but I have little understanding of it.

 

[zocalo]

Recent drones like the Mavic 2 Pro and Phantom 4 currently have a stills resolution of 20MP. The angle of view on the M2P is 77deg, so your required altitude will depend on how much detail you need on the ground in terms of pixels per cm/inch - if you can provide that, you can calculate the max altitude with a little bit of trig. The higher the better as that means less need for obstacle avoidance and less data to process. You could also do that with 4K video and a slightly lower altitude, but that means a LOT more data, even at slow frame rates.

There are apps that let you re-fly previous flight paths and grids, but the precision isn't perfectly accurate so you need to make allowances depending on your tolerances. I'd look into the image tiling approach mentioned by @Doppler above then scale and align images to look for differences. Generally you want to hover for sharp stills though, so you might actually be better flying the grid manually and use the map on the controller to make sure that you are doing reasonably accurate parallel lines with enough of an overlap for the image stitching tool to make decent joins. All images should be GPS tagged, so that aspect is covered.

Collision avoidance works, but is still pretty basic compared to what you see on TV - it's more a hail mary to save the drone than anything you'd rely on at this point. I certainly wouldn't expect to give a drone a search grid, let it loose below the canopy of a forest, and expect to have a functional drone or usable data at the end of the mission. Realistically, if you can be flying above the bulk of the foliage (e.g. all of the bushes and other shrubery) and only have to dodge the occassional tree, you'll probably be OK, but you'll still need to monitor the flight and be ready to intervene just in case.

 

[WildDog]

Thanks everyone for your input. I can see I may have been a little unrealistic as to the way a drone operates. I could fly the drone by hand but as was mentioned the bushes/trees may present more of a problem than its worth. To get above the tree line would take me up around 40m. Im not sure I'm going to be able to identify types of gravels and rocks from that hight.

The main purpose I had for the drone was to help me prospect for gold. I was hoping I could take video footage of the forest by flying the drone back and forth with gaps of 10m -20m until I covered most of the area. What i would be looking for was rocks/gravels that are associated with gold. At the moment i walk many miles analyzing the ground as I walk. I was hoping a drone could cover more ground faster. ... I may have to continue walking I think.

 

[brett8883]

HI, newbie here with a question regarding the capabilities of drones. I may have an unreasonable expectation of what a drone is capable of doing so I thought id ask here first as I know very little about them

I'm wanting to view the ground and see what type of rocks/soil conditions are present in the bush.

To do this the drone will need to fly reasonable close to the ground (6 foot) and be able to fly around trees. I would like to have a pre-planned flight path and have the drone fly the mission automatically.
I then want to be able to view the video/data on a computer at home and when I see an area of interest be able to know the GPS coordinates of that spot. At the moment I'm walking miles on foot and covering little ground.

That was my ideal scenario, the other option would be to fly it manually but that's going to take a lot longer and I want to cover as much ground as possible.

Any advice on a DJI model that might do all this?

I think you can do this I’m not really sure why not. 6 feet might be a little low but the resolution is high enough you can zoom in.

The inspire has a tap fly mode that will allow you to choose a coordinate or location on the screen and it will fly there automatically. If it meets an obstacle it will fly around it. You can actually use it’s dedicated tap fly camera to monitor the forward path of the flight while it lasts main camera is pointed at the ground taking the pictures you want.

It’s a heck of a first drone but Inspire can do it.

Mavic does have a tap fly mode that will fly around obstacles but as others have mentioned it nerve racking to not be able to see where it’s flying and the obstacle sensors on the Mavic are more a “fail-safe” then something to be relied on.

So yes we have the technology to do exactly that but you are looking at more of a professional model then a consumer model. Manual flight is pretty easy to master though I think with a little practice you’ll find that one of the reasons drones have become so popular is that anyone can fly them

 

[stonecherub]

As a geologist, I do this sort of thing regularly, but entirely under Danny control in the desert where vegetation is (mostly) sparse and out of the way. My ancient Kelty pack holds water bottles in the bottom, a 30 * 50 cm plywood take-off panel, a foldable artist's stool, my drone case, and a notebook - about 30 pounds.

The panel goes onto a level place, adjusted with small rocks as need-be. The Pro gets unfolded onto the panel and turned on. My notebook has a page that holds a dozen SD cards, each with a 3-5 cm strip of fluorescent green tape (try to find a black SD chip in a pile of black rocks, sometime), and I use one for each flight. With controller and computer on and connected, I always calibrate the compass (and some times have to move because the basalt is lightning magnetized).

Then I fly, usually above the low bushes. If I'm in wash, which can have trees over 6 m height, I do a quick 360 if I think I'm close to any of them. I can usually photograph rock structures close enough to identify them. If I cared about the plants, I'm sure I could identify them, as well. I tried to follow a big-horn sheep, one day, but he was smarter than me.

Recovery is by hand, the panel is too small to always hit perfectly when in the rocks and the flat desert surface has too much dust. When I pack-up, I connect the controller and the iPad to a power pack in the case which usually charges both to 100% by the time I'm ready to fly again.

All of my flying is in the Mexican desert and practically none is VLOS. With my old eyes, the Mavic Pro is too small and disappears beyond 3-500 m and none of the people who go with me can see it any farther away.

 

[Mossiback]

It depends on how many trees you have to deal with, but you could use a M2Z, flying manually above the trees. You can survey an area and use the telephoto to zoom in as needed to see details. Not automated but will have reduced risk of crash. If it can capture the detail you need then it would be a lot more efficient than waking.

 

[brett8883]

It depends on how many trees you have to deal with, but you could use a M2Z, flying manually above the trees. You can survey an area and use the telephoto to zoom in as needed to see details. Not automated but will have reduced risk of crash. If it can capture the detail you need then it would be a lot more efficient than waking.

The zoom is a great idea don’t know why I didn’t think of that! Why would you say you can’t automate it though? You could just use Pix4DCapture or any other mapping program.

Here is a Pix4DCapture sample. Keep in mind this was taken from over 100’ up so if you do it closer to the surface you’d get better resolution but you can zoom in on this one and the res is still pretty good. You see that it’s overlaid on a map and you can click any point on it to record the coordinate.

Pix4D Cloud

 

[Mossiback]

I did not say that you could not automate it, I just stated that doing it manually will reduce the risk of crashing and would be more efficient than walking.

 

[brett8883]

I did not say that you could not automate it, I just stated that doing it manually will reduce the risk of crashing and would be more efficient than walking.

Sorry misunderstood,

 

[zocalo]

It depends on how many trees you have to deal with, but you could use a M2Z, flying manually above the trees. You can survey an area and use the telephoto to zoom in as needed to see details. Not automated but will have reduced risk of crash. If it can capture the detail you need then it would be a lot more efficient than waking.

Having done the math ages ago I'm not so sure the Zoom is actually that much better than the Pro. It might have a 48mm lens, but that means a narrower angle of view and less MP (12 v 20), so the two more or less cancel out on the altitude required for a given level of detail. You'll also be more prone to image blur if the drone isn't quite steady at 48mm than you would be at the M2P's 28mm.

I don't think the Zoom's 9-shot 48MP stills mode helps either, but I don't have one and I'm not totally sure how it works in practice. If I understand it correctly, you'll still get the same level of detail as you would in a 12MP still, but just with a larger FoV - can anyone confirm? Either way, that would definitely require you to hover the drone for each shot and be even more prone to image blur if there was enough wind.

Realistically, I think the OP probably needs to find a friendly pilot (or two) prepared to do a few test runs to establish what altitude is required for a given lens/resolution using a Mavic/Phantoms and decide based on that. Alternatively, there's the Inspire which would let you have high MP and a longer focal length that might get over the tree tops and still provide enough detail, but that's a significantly more expensive option.

 

[JoeDimwit]

A Zenmuse Z30 should be able to get enough resolution to count gravel, let alone identify it from 30-50 meters. But, you’re looking at something like a Matrice to fly it.

 

[Keule]

A Zenmuse Z30 should be able to get enough resolution

The Z30 is not the right tool (only 2 MP, but a 30x optical zoom)
a X7 with 50mm lens is the way to go - That'll give you enough resolution for the intended task.

 

[AMann]

Are you doing soil survey mapping? A drone could drop down to a low level and take a photo then rise again, but as stberlin mentions, it would probably end up stuck in a tree or bush. How about a autonomous rover? You could use a drone hovering overhead to help guide it and to relay telemetry/control signals to it from your base station. There are a lot of Arduino based rovers and drone building plans and instructions online, seriously look it up!

 

[NAVMAV]

Think I feel a headache coming on...~

Rgds, NAVMAV

 

[Aussie Oldtimer]

HI, newbie here with a question regarding the capabilities of drones. I may have an unreasonable expectation of what a drone is capable of doing so I thought id ask here first as I know very little about them

I'm wanting to view the ground and see what type of rocks/soil conditions are present in the bush.

To do this the drone will need to fly reasonable close to the ground (6 foot) and be able to fly around trees. I would like to have a pre-planned flight path and have the drone fly the mission automatically.
I then want to be able to view the video/data on a computer at home and when I see an area of interest be able to know the GPS coordinates of that spot. At the moment I'm walking miles on foot and covering little ground.

That was my ideal scenario, the other option would be to fly it manually but that's going to take a lot longer and I want to cover as much ground as possible.

Any advice on a DJI model that might do all this?

Technically, you can fly within 6’ of the ground as long as there are no trees or other obstacles in the way. I've flown around 1’ above a flat and level beach for hundreds of M

If you’re planning on flying around in some treeless areas, why not?

Your OP said that you want to dodge trees, if there are the odd tree here and there, shouldnt be an issue. If youre talking about zooming around a forest full of trees, no way

I’ll hazard a guess and say that you’re gold prospecting?

 

[WildDog]

Technically, you can fly within 6’ of the ground as long as there are no trees or other obstacles in the way. I've flown around 1’ above a flat and level beach for hundreds of M

If you’re planning on flying around in some treeless areas, why not?

Your OP said that you want to dodge trees, if there are the odd tree here and there, shouldnt be an issue. If youre talking about zooming around a forest full of trees, no way

I’ll hazard a guess and say that you’re gold prospecting?

Yes, for gold prospecting. I think the trees/bushes are going to be the problem. Some areas are reasonably open, others there would be a fair amount of weaving involved.

 

[Canuk]

I have flown at low level in the bush but the range is not good when there are lots of brush . I have flown along animal trails . You must set the drone to hover if signal loss happens