Aerial Photography (redux)
2005-03-22 21:14:08.9265+00 by
ebradway
6 comments
A while back, I started playing with ways to
take digital aerial photographs from a suspended platform. My initial attempt using a Mini-ITX computer didn't work too well. It is too heavy for the balloon I am using. A larger balloon would increase my operational cost signficantly as well.
Remembering Dan's comment on using the NTSC out on the camera got me thinking in a new direction. I ended up buying an Olympus Stylus 410 and a
Radio Shack A/V Signal Sender. The Olympus gives me 4Mpixels, NTSC out for the viewfinder AND an IR remote. The A/V Signal sender transmists the NTSC signal to the ground, retransmits the IR remote signal, and can be powered effectively by two 9V batteries in parallel. The entire gondola now weighs in under 1kg with full power.
More information here.[ related topics:
Photography Invention and Design Work, productivity and environment Eric's Life Maps & Mapping
]
comments in ascending chronological order (reverse):
#Comment Re: made: 2005-03-22 21:41:24.401589+00 by:
ebradway
Also, I am considering returning the Stylus 410. I can get an Olympus C-60 for just a little more money. It's 6Mpix and only a little heavier (198g vs. 159g). Has anyone had any personal experience with the C-60?
#Comment Re: made: 2005-03-22 21:57:13.474224+00 by:
Dan Lyke
Okay, now that you've got my interest piqued, how about some pictures from the camera?
#Comment Re: made: 2005-03-23 00:04:47.754666+00 by:
ebradway
[edit history]
Ok... I needed to run out the office before I had a chance to setup an online gallery. Here are some images:
From about 100ft
From about 400ft
And the raison d'etre, a 400ft image georeferenced to the ground control points:
#Comment Re: made: 2005-03-23 00:34:16.528663+00 by:
Dan Lyke
Cool. Too bad Ben doesn't yet have texture paging in VTP, but it does make me want to see how to integrate external imagery into WorldWind.
#Comment Re: made: 2005-03-23 02:43:51.409216+00 by:
meuon
[edit history]
CONGRATS! That is SWEET! - I like that you essentially went 'analog' - much simpler. And the pic quality in excellent!
Any reason to strip plastic cases and such off for a few more ounces
of weight savings?
#Comment Re: made: 2005-03-23 13:35:02.761469+00 by:
ebradway
[edit history]
The current weight is quite fine. I will be redesigning the gondola chassis so it will be lighter and provide three outriggers for the tethers to help stabalize the platform. I will also spend some time looking for better tether.
The two avantages to further weight reductions are:
- Increased lift helps overcome wind problems. The spherical balloon tends to get pushed to the ground with any real wind. A blimp shaped ballon would work even better, but they are more expensive.
- I could potentially use a smaller balloon, which means lower purchase cost and operational cost (using less helium).
Some things I plan to test on my next flight:
- How does lift and wind speed interact to affect flight. That is, I want to create a graph that plots lift against windspeed so I can better predict how well the system will function based on the wind and maybe underinflate the balloon if possible.
- Ways of marking control points on the ground.
- How to setup the chassis to allow for oblique photos.
A while back, I started playing with ways to take digital aerial photographs from a suspended platform. My initial attempt using a Mini-ITX computer didn't work too well. It is too heavy for the balloon I am using. A larger balloon would increase my operational cost signficantly as well.
Remembering Dan's comment on using the NTSC out on the camera got me thinking in a new direction. I ended up buying an Olympus Stylus 410 and a Radio Shack A/V Signal Sender. The Olympus gives me 4Mpixels, NTSC out for the viewfinder AND an IR remote. The A/V Signal sender transmists the NTSC signal to the ground, retransmits the IR remote signal, and can be powered effectively by two 9V batteries in parallel. The entire gondola now weighs in under 1kg with full power. More information here.
