Dear Raghunathan,

nice replies to this thread from Dennis, Jez and Abhishek, up to now.

Well, don't underestimate force of big parabolic antennas. And noise is not that big problem, because at earth recievers are cooled by liquid nitrogen, I think, and on Mars ambient temperature is rather low, at least lower than -70°C, when I'm right.

Choose of right carrier wavelength is crucial. There are some bands, where atmosphere has an absorption minimum.

And last but not least, today there are data correction schemes available, producing a bright and subtle picture from a bag of garbage, example given! Once, I have had a look into a text book, and I can tell you, it's so complicated you can't imagine. Do you remember rendevouz with Ghiotto? Super computers needed weeks and months for fabricating corrected pictures. I think Mars Rover uses some similar data correction scheme, much less complex, of course. Many many redundant information will be transmitted, so that data loss is negligible.

But make no mistake: What those NASA guys use is state of the art of state of the art of electronics...

Have a nice day,
Kai