Aerial View Drone Mapping

Shawn

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Shawn
OK Interwebs brain trust...can this be done without spending a fortune?

I need an accurate aerial satellite view of a 30-ish acre plot of land (think city park) that has about 15-20% tree coverage...but I need that view to be from about 10' above the ground under the tree canopy to see exactly where curbs, parking spaces, existing fences, tree trunks are, etc. that are under those trees.

Google Earth gets me 80% of what I need but wanna find a way to capture and stitch together what is under the trees to do accurate layouts and diagrams for an annual special event and there are no to scale CAD drawings available.

Working on a broke Non Profit with no budget level...not Google money!
 
If the leaves fall off the trees (winter), you could do a drone flight over the whole thing in about 20 minutes and have someone process the images for you inexpensively. That would give you a nice complete orthophoto of the whole property.

If it’s evergreens and they don’t come off, that gets a little harder. You can’t really fly a drone that low to get good aerial imagery because it needs a lot of overlap to stitch the pictures together. Drones with lidar could do it but the price just went way up.

If you just need to fill in google earth, the cheapest way would be to just take an afternoon with a wheel and a tape measure to sketch it out. If you have a friend that’ll let you borrow a GPS total station, that could make quick work of it too.
 
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Photogrammetry. Obliques from a drone or a plane.
Something like https://www.pix4d.com/ We used to help quarries determine their volumes but most of that business is going to drones on site now since they can do it on demand in most weather.
 
I know our city and county have GIS aerial imagery that is intentionally flown early in spring, between the snow melt and before the leaves get in the trees to give the best view under the trees.
 
I know our city and county have GIS aerial imagery that is intentionally flown early in spring, between the snow melt and before the leaves get in the trees to give the best view under the trees.

Norther California and lots of evergreens...tree are full year round unfortunately.
 
Our chief engineer:

"Satellite view and birds eye view will only get you the tops of surfaces in orthomosaics. Anything in between the highest surface will never show up in an ortho. Flying lower is not safe in grid patterns. Only way I see a solution is to either create a 3D mesh or dense point cloud of those areas by doing orbits around the trees to capture the areas underneath the canopy. After those areas get captured, they can try removing the canopy from the point cloud and generating the ortho without it. That should give them what they're looking for if they know what they're doing."

TLDR it sounds like a drone isn't the cheapest tool for your job.
 
Norther California and lots of evergreens...tree are full year round unfortunately.

Have you checked the county GIS yet. Many of them contract for regular lidar surveys so they can tax their citizens more for any additions they may have made to their houses.
 
Our chief engineer:

"Satellite view and birds eye view will only get you the tops of surfaces in orthomosaics. Anything in between the highest surface will never show up in an ortho. Flying lower is not safe in grid patterns. Only way I see a solution is to either create a 3D mesh or dense point cloud of those areas by doing orbits around the trees to capture the areas underneath the canopy. After those areas get captured, they can try removing the canopy from the point cloud and generating the ortho without it. That should give them what they're looking for if they know what they're doing."

TLDR it sounds like a drone isn't the cheapest tool for your job.

That is what I was afraid of...so I do not need a mapping drone, I need a mapping blimp.

After a lot of digging I am sensing a market opportunity here to develop something for this application. I can't be the only one needed this without having to spend a bazillion dollars on technology and stitching expertise labor.

I may just go strap a GoPro to a balloon and overlay the pictures where I need them.
 
I think what he means is that you can't fly below the trees to get any appreciable data (like @jheyen said) so you have to do a bunch of orbits above each tree or cluster of trees to get what ground imagery you can from above looking down at an angle, then remove the trees.
 
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Our chief engineer:

"Satellite view and birds eye view will only get you the tops of surfaces in orthomosaics. Anything in between the highest surface will never show up in an ortho. Flying lower is not safe in grid patterns. Only way I see a solution is to either create a 3D mesh or dense point cloud of those areas by doing orbits around the trees to capture the areas underneath the canopy. After those areas get captured, they can try removing the canopy from the point cloud and generating the ortho without it. That should give them what they're looking for if they know what they're doing."

TLDR it sounds like a drone isn't the cheapest tool for your job.
Still cheaper than a plane or a helicopter. For us to map that vertically plane or helicopter would Basically it's oblique 3d mesh mapping. Pix4d is $292/mo. plus the drone flight. Might look to see if there's someone in the area that already has a subscription that would be willing to help you if you can get imagery that meets the requirements.
That is what I was afraid of...so I do not need a mapping drone, I need a mapping blimp.

After a lot of digging I am sensing a market opportunity here to develop something for this application. I can't be the only one needed this without having to spend a bazillion dollars on technology and stitching expertise labor.

I may just go strap a GoPro to a balloon and overlay the pictures where I need them.
No, you just need 3d oblique imagery, not vertical, that's translated into a map.
 
I think what he means is that you can't fly below the trees to get any appreciable data (like @jheyen said) so you have to do a bunch of orbits around each tree or cluster of trees to get what ground imagery you can from above looking down at an angle, then remove the trees.
Right. If there are a bunch of trees that are too dense, nothing's gonna help unless it can get under the canopy.
 
We used to do aerial topo surveys. At the time, there was nothing but a couple of guys with an instrument and data collector that could locate improvements beneath tree canopy. I've been out of it since 2013, but I doubt there has been anything invented that will do what you are asking other than a field survey crew.

I'd get some bids from some small, local surveyors to locate the obscured improvements and combine it with data that is already available. Sometimes, topo data from counties can be pretty accurate

The less you need the cheaper it will be. No elevation data, no boundary survey or research required, just a map of an area for planning purposes. They don't need to survey the crap out of the place, just locate what can't already be seen.

We used to call what you are after a 'basemap', we'd make them for developers all the time who were looking at a piece of property and deciding what to do with it. We download as much GIS data as we could and put it on paper with a bunch of disclaimers about it not being a real survey. I'm on the east coast, they may call it something else there. I could usually do them in a couple of hours with county topo, building locations, etc...
 
If this isn't what you need, maybe it will at least give you some ideas of how to get there... Just ignore the foreflight parts as that doesn't seem applicable to your need.

 
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