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I was inspired by experiments being made at the Australian National University (see Centre for Visual Sciences) to try my hand at horizon detection for aerial vehicals using parabolic mirrors.
The first step was to have an aerial platform with a working digital camera. For details of this see RC Camera and RC Video.
The second step was to obtain a mirror and to develop the software to analyse the video produced. The light weight mirror I used was a christmas decoration. For software I created a plugin to VirtualDub, the details of which can be found at Polar Filter.
Some pics of the model with the mirror and camera fitted:
The slow flyer used to have foam wheels but they kept getting ripped off, so I've gone a little more basic with these wire draggers. You'll notice that the propeller has suffered also, but this only ever happened when I tried to fly without any undercarrage.
The first flight with the mirror was a success but alignment is a problem and re-alignment is necessary after every landing.
The mirror tends to act like a concave lens, so either a macro-lens (a convex lens) needs to be fitted to the front of the camera or (as I did) the lens needs to be turned till it is further from the sensor. Some nail polish remover might be necessary to free the lens adjustment.
While it is intended that the camera takes videos, these are a bit large, so I've shown here a higher resolution still.
I've highlighted what I wishfully believe was a galah (a type of Australian parrot) as a flock of these playful birds had joined my slowflyer for a couple of circuits of the oval. Who could even think of putting such creatures in a cage!
The larger squiggles are either kamakzi vultures or are left by the passage of the propeller.
The yellow bulbous feature towards the tail of the aircraft is in fact a glob of epoxy glue which refused to budge.
After processing the image through VirtualDub, the red and green components can be removed and an approximation of the horizon is made:
For a description of the software I created see Polar Filter.
The image can be further processed to remove the wing colours which may not be a good idea for a transparent wing as with my slow flyer:
With or without horizon detection the image may be remapped (or unwrapped) to give a 360 degree panoramic image:
There is a bit too much detail of the model in these remaps because I had the inner circle set too small for effect. The ground is a bit dark but there is detail there which can be boosted:
If you have a high speed internet you might want to look at a highly compressed AVI video of the remapped video = 208kB. You'll also need a copy of the XVid codex installed on your PC which I believe you'll find at http://www.xvidmovies.com/codec/.
Have a quick look at my RCcamera, RCVideo and Polar Filter pages.
If this wasn't really what you were looking for in aerial camera's there is a good chance you will find it at one of the following sites: