Aerial Thermographic Video: Othogonal Aspect
Veritical aerial thermography of an industrial subject, shot 5/1/11.
This type of video is atypical-it's much more difficult to collect than oblique aerial thermography but allows the registration of each image (frame) in the video with a latitude and longitude, making map-based indexing possible.
The "exposure" changes as the subject progresses across the frame in order to prevent "clipping" or truncating information on the temperature levels in the current image (video is essentially a series of still images that are displayed do quickly that the human eye cannot distinguishe the transition between them).
In the case of this video, the original is shot at about 9 frames per second, but in order to best suit the video format for the embed player I've recomposited it to 24 frames per second. You'll notice some "jump" that reflects the video CoDec (Compression-Decompression) having a blast converting 9.13 frames per second to 24 frames per second using the ON2 VP6 routine.
I'm avoiding making any thermographic diagnoses on the contents of the video, but there's plenty to see down there...
L
May 4th, 2011 - 17:45
Thanks for the great demo!
The play button [>] on the embedded player covered up the lower F degrees. Just wondering what range it was showing?
9 FPS – with lat long tags on each frame. Nice!!
Do you know what the estimated airspeed was?
May 4th, 2011 - 19:11
Ooops! Thanks for letting me know-I moved the player controls down below the video frame so we’re all set.
I’d estimate we were at 90 KIAS with a northwest (the flight line is south) quartering tail of about 15 knots, so presuming I was covering ground at about 100 knots. The frames are very sharp so the motion blur is inconsequential at 640×480. We’ve shot “low” at up to 160 KIAS with satisfactory results-I can run the trig on the blur and at some point in time will cook up a spreadsheet on ground sample distance vs. speed & altitude…
Thanks!
May 13th, 2011 - 12:16
Great stuff Leo