How Spirit Takes Pictures

Some Clown writes "MSNBC has a great article on the details of the camera system on the Mars Rover titled How Sprit makes great photos. Apparently the high resolution images are all done with a 1-megapixel camera. All the money is in the CCD and Lens. The hardcore digital photographers in the crowd will probably find the article to be only a teaser on the technical specs, but the rest of us in the unwashed masses should find it interesting."

Comments

Original

[Gherald]

Why not link directly to the original article?

Re:I was honestly surprised.

[froody]

It's important to note that in a color digicam each "pixel" only senses 1 color. The NASA cam is a black and white, and to make color they take 3 shots with different filters. This makes it equivalent to a consumer 3MP camera.
They also have a nice lens and a large sensor which helps as well.

Tim

Re:It's All About The Optics

[Anonymous Coward]

You can also do cunning tricks with moving the camera fractions of a pixel to generate 'super-resolution' images - I'm almost afraid to think what the images from Spirit could be like with this technique.

They've talked about using it to take pictures of the hills a few kilometres away - even if the rover doesn't reach them, they should still get some very impressive images of them.

Re:Interesting, but..

[jmh_az]

It extracts data by looking at the return levels at the various wavelenghts of the filters, among other things. With image processing software like IRAF you can get an amazing amount of information out of an image. Also, conventional comsumer CCD cameras use one CCD device with a RGB patterned color filter literally painted onto the face of the CCD to get red, green and blue. High-end cameras use three CCD's with seperate filters in front of each imaging device and splitter prisms to direct the light. Since things like weight and complexity are issues when building spacecraft, they accomplish the same thing as the high-end cameras here on earth by using one CCD and a filter wheel. This approach also allows them to do other things, such as take images through polarizers, or have magnification if they need it, and all in one camera package. And, last but not least, these cameras are tested and calibrated to within an inch of their lives before they ever leave the ground, so the researchers know exactly what the dark current (electronic noise), flat field (pixal responsiveness across the entire CCD) and defect characteristics for the CCD are. This information is then used to subtract out a lot of the noise and imperfections, leaving as much of the original data for analysis as possible. That analysis is the stuff of research papers like this one.

Hope that was useful.