[X] My Assistant

[djellison]

http://www.msss.com/mars_images/moc/2006/01/03/index.html


Doug

[djellison]

The way I figure it, that to 'resolve' something, you have to be able to say that there will be more than one pixel that is nothing except that object. The CPROTO images of the rovers are cool, but no one pixel is nothing-but-rover, they'll all just about include a big chunk of ground, and a bit of rover in the mix, contributing to the brightness of that pixel.

So - say you have a 1m resolution - and a 1x1m object, you could be REALLY unlucky and have the join of 4 pixels in the middle of your object and all you would have is 4 pixels that are 75% ground and 25% object. You've not resolved it

If you had a 2 x 2m object, there's no way in which the 'pixels could fall' where by you dont have at least one pixel that's totally saturated with the object and nothing else.

But to have be sure of what you're looking at - to have multiple pixels of the object in question - (and if you're have multiple pixels then it's going to have to be 2 x 2 pixels of it ) then you're looking at a minimum object size of 3 x 3 m - that's 3 x the 'resolution' of the camera.

So - transpose that onto the Peoples Camera (HiRISE) - and you have 3 x 30cm, which is, as near as makes no difference, 1 metre Any 1x1m object is certain to be the only source of photons in at least 4 pixel elements when you have a 30 x 30cm resolution.

I dont think there's any hard and fast rules on this. Like much imaging, it's a judgement call at the end of the day. I think my two simualtions are fairly representitive of the camera's abilities given perfect conditions. SS loved it when I gave him a little print out in a frame as a thankyou for his updates and hardwork on behalf of this place. I dont think the HiRISE team had done anything like that ( Steve's on the science team for it ) - and it certainly packed some wow factor. I dont think there will be a single HiRISE image that doesnt make you go "WOAH!"

That's my non-expert guestimated take on the situation anyway. It sort of makes sense...ish

Doug