Air 2S and mapping overlap question

mavictk · Feb 22, 2023

I am new to mapping and am trying to figure out the math. I know that the Air 2S has a FOV of 88 degrees and can use trig to figure out how many feet of land can be pictured at various altitudes. Now, for improved mapping I know that a certain overlap of pictures is required. Suppose that I plan for a 90% overlap using the 88 degree FOV that would be the overlap for horizontal size of 5472 pixels. Now, what about the vertical overlap. Since there is a 3 by 2 ratio or 3648 pixels would I need to cut the distance between pictures by two thirds to make sure I am getting a 90% overlap of pictures from the horizontal overlap calculation?

By way of example I calculated that if I fly at 120 feet then each picture is 232 feet horizontally and, therefore I need to take a picture every 23 feet for 90% overlap horizontally. What about vertically? I am thinking that I need to set the actual feet between pictures at 15 or so feet to get the 90% overlap on vertical and horizontal will just have a greater overlap. Right?

zeusfl · Feb 22, 2023

I am not an expert on mapping but normally I use 75% frontal by 70% Sides. I personally believe depending what do you want to map 120 FT is way to close. I will start with 275FT. I never had that much overlap but probably will be fine taking pictures that close to the ground.

Meta4 · Feb 22, 2023

mavictk said:
By way of example I calculated that if I fly at 120 feet then each picture is 232 feet horizontally and, therefore I need to take a picture every 23 feet for 90% overlap horizontally. What about vertically? I am thinking that I need to set the actual feet between pictures at 15 or so feet to get the 90% overlap on vertical and horizontal will just have a greater overlap. Right?

You are making things much too hard for yourself.
As long as you use an Apple device, you can get DroneDeploy to plan your flights, plot the grid, calculate overlaps etc and fly the mission while capturing the images.

mavictk · Feb 23, 2023

Meta4 said:
You are making things much too hard for yourself.
As long as you use an Apple device, you can get DroneDeploy to plan your flights, plot the grid, calculate overlaps etc and fly the mission while capturing the images.

I use an RC Pro …. I admit to wanting to understand more and the math is interesting. Lastly, from a guy who is near genius with crash and flyaway analysis you, Meta4, certainly put in the time to understand drone flight characteristics for which I applaud you and thank you for the analysis you did for me.

PHZ · Feb 23, 2023

Does DroneDeploy work with an Air2S? Or for that matter, with a Mavic 3?
I do a lot of mapping with an Inspire 2 and sometimes with a Mavic 2 Pro using DD. If doing a standard map, (no GCPs or 3D), I will set up the X4s camera, also an 88 degree FOV, to 85 and 80 overlap. I always try to get close to a 500th shutter speed even at the expense of raising ISO. The X4S has a mechanical shutter, which the Air2S does not, so a faster shutter speed for the Air2S or my M2P is even more critical.
Also, usually I fly between 150-200’ depending on various factors.
I flew a “hand” map at 70’ inside a major sports stadium with a semi-enclosed roof with an Inspire 1 and intermittent GPS. Almost nailed the newly installed scoreboard but my trusty VO saved me. He has season tickets and always admires the intact scoreboard. That is why I carry liability drone insurance.

zeusfl · Feb 23, 2023

DroneDeploy, Dronelink, Pix4D, and many mores. I like Dronelink since is cheaper than DroneDeploy but I prefer DroneDeploy if money was not a problem.