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Using drones for photoreal ground

Dimus

Dimus

SOH-CM-2025
A good friend has a nice drone. He always told me how his drone can map the ground in high quality imagery. Yesterday he mapped a small area of deserted ground abt 500x500m close to where I live. I asked him in what formats he could export the data and he mentioned the magic word Geotiff. So he gives me the tif file and I quickly passed it through resampler without any additional scenery work and here's what I got:

P20gS8w.jpg


V1pci5Y.jpg


exqj57t.jpg


The image is 30cm/pixel and the color quality is much better than satellite images. I did not do any color correction in this one and very little is needed. He tells me that the drone can also get elevation data.

There might be good future in this, provided of course one is allowed to fly a drone over the area of interest. Airports are probably impossible, unless they are small fields and one arranges to do this with them on idle hours. Other landmarks may be easier to do, although drone flight rules are getting stricter now.
 
Hi Dimus, it looks great, but it is always the same like you take photos from airplanes or helicopters. You can´t cover areas of more than 1000x1000m without having big issues with the distortions on edges. But it is right - to cover a smaller range, a drone could be very nice.

Thomas
 
Thomas, this is not a single picture. It is a result of an automatic survey mission that the drone was set to complete, so no distortion. There are several apps for Android or IOS that can make survey missions for the drone. My friend is using "PrecisionFlight", which is free:

https://itunes.apple.com/us/app/precisionflight-for-dji/id1112592228?mt=8

Using this app, the limits of the area to be covered is defined in google maps, as well as the required resolution, which defines the altitude at which the drone would fly. Then the drone is sent on its own to follow the mission and it takes hundreds of overlapping pictures with saved geodata, bu following a zig-zag course over the area. This small area was done in 5 minutes. The pictures are then uploaded to the apps server: http://www.precisionhawk.com/precisionmapper and compiled into 1 tiff file, together with the coordinates of its edges. This is all the data one needs to make an inf file and pass it through the resampler in the SDK.

Of course the drone should be one that has the capability of automatic operation under GPS guidance without user input. My friend's drone is this one: https://www.amazon.com/DJI-CP-PT-000312-Phantom-4-Quadcopter/dp/B01CFXQZD0

If you select lower res like 1m/pixel, much larger areas can be covered in one battery time which is 25 minutes, provided you can fly over freely.

I may also add that these survey application sites are not free, just free to try for one month. Then they are subscription based, and not that cheap.
 
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