How do hybrid EO/IR systems work in UAV applications?

August 30, 2007 9:38 AM

How do hybrid EO/IR systems work in UAV applications?

I know next to nothing about optics or optical systems and i'm pretty weak on physics, but i've recently become very fascinated with UAVs. I've been reading about hybrid EO/IR systems, where the aircraft senses both optical information (e.g. pictures) as well as infrared photos. I understand roughly how a gimbal and gyroscopes work for positioning the camera as well as how the camera knows what it is looking at in terms of positioning, but what I don't understand is what an actual assembly looks like. Is there a lens that is used to magnify the incoming IR wavelengths? Is it usually the same lens for multiple sensors with some kind of prism or beam splitter? Can you provide more detail? I've tried to do a little research but the background I'd need in optics is more time consuming than makes sense for me.

posted by arimathea to science & nature (2 comments total)

Many of the new assemblies do not look so different from the old assemblies. The best source of information for you will be books on aerial photography. (note that I don't think that the Wiki link is the best, but it does contain a lot of useful references).

If you have a CS background, you should look into machine vision books. Many of them contain information which would help you understand the kind of equipment and interpretation going on.
posted by fake at 10:11 AM on August 30, 2007

This PDF brochure from L-3 Communications has fuzzy photos of a lot of their products. It looks like it's typical to have separate lenses for visible/near-IR vs. far(thermal)-IR but they also have ‘shared aperture’ systems.

I suspect it's pretty hard to do visible and thermal-IR imaging through the same set of optics. Thermal IR has enough longer wavelength you need to use different lens materials (germanium is/was a common choice if you don't need to be transparent to visible light as well) and I'd guess the overall system design has pretty different tradeoffs as well. But it's clearly not impossible.
posted by hattifattener at 11:38 AM on August 30, 2007