Alpha is set to such an angle that the horizon will touch the center of the image. You can alter this angle to see how the projection of the horizon changes (at -90 degrees it's a circle, for example). Negative angles indicate pointing the camera down toward the Earth, positive angles for pointing it up (the graphs will still render, but the y=tan(alpha) line is the indicator that you shouldn't see anything below it).
hozP, vertP, FOV and H are the variables I recommend changing to see what happens to pixelDelta.
The formulae used were derived by considering a perfect camera sensor as a plane intersecting a double cone over the Earth; it's nothing too complicated, just a little tedious. I might post a derivation if I can be bothered.
The initial inputs (H about 33 kilometers, FOV about 85 degrees) are roughly in line with a recent post in this subreddit containing an image from a GoPro somewhere below 109000 feet.
Please notify me if the link doesn't work.
Alpha is set to such an angle that the horizon will touch the center of the image. You can alter this angle to see how the projection of the horizon changes (at -90 degrees it's a circle, for example). Negative angles indicate pointing the camera down toward the Earth, positive angles for pointing it up (the graphs will still render, but the y=tan(alpha) line is the indicator that you shouldn't see anything below it).
hozP, vertP, FOV and H are the variables I recommend changing to see what happens to pixelDelta.
The formulae used were derived by considering a perfect camera sensor as a plane intersecting a double cone over the Earth; it's nothing too complicated, just a little tedious. I might post a derivation if I can be bothered.
The initial inputs (H about 33 kilometers, FOV about 85 degrees) are roughly in line with a recent post in this subreddit containing an image from a GoPro somewhere below 109000 feet.
I am actually in team that would send ballon 30km high. There should be beautiful curvature