AVIATR - Titan Airplane Mission Concept, Proposed unmanned aerial exploration of Titan Options

[Juramike]

The AVIATR mission concept is an unmanned aerial vehicle that would fly over Titan’s surface. It’s nominal one year mission would enable detailed high-resolution images of Titan’s diverse landscapes for better comparison to Earth’s geological processes. Selected regions could be imaged at resolutions near 30 cm/pixel, equivalent to current HiRise imaging of Mars. In addition, atmospheric sampling would allow a profile of Titan’s thick lower atmosphere and how it relates to Earth’s atmospheric processes and weather systems.

Further details of the AVIATR mission concept were presented at the Lunar and Planetary Sciences Conference 2010 and at Titan Through Time 2010.
See: Barnes et al. LPSC 41 (2010) Abstract 2551. “AVIATR: Aerial Vehicle for In-situ and Airborne Titan Reconnaissance.”
Freely available here: http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2551.pdf

And also: http://www.info.uidaho.edu/documents/2010%...18467&doc=1

[Greg Hullender]

Forgive my ignorance, but shouldn't the resolution just be a simple calculation from the field of view, the distance to Titan, and the dimension of the camera in pixels? I realize SAR isn't quite the same as a simple picture, but can it be THAT different?

The discussion of how accurate things need to be reminds me of something a senior astronomy major told me when I was a freshman at Caltech back in the 1970s:

Mathematicians insist on exact answers. Pi is NOT 3.1416
Chemists and Engineers generally settle for a few parts per thousand error.
Physicists are happy to get the order of magnitude right.
Except Astro-Physicists, who just want to get the order of magnitude of the order of magnitude right.
And Computer Scientists only need to know if it's zero or not.

--Greg :-)

[Jason W Barnes]

Forgive my ignorance, but shouldn't the resolution just be a simple calculation from the field of view, the distance to Titan, and the dimension of the camera in pixels? I realize SAR isn't quite the same as a simple picture, but can it be THAT different?

Short answer: yes.

The real problem, though, and one that is quite common, is that what you're describing is the pixel scale. It is not the resolution. Resolution is the smallest thing that you can resolve, which is always larger than a pixel. In fact the theoretical minimum is 2 pixels. Experience with HiRISE is that about 3 pixels is what it really takes to resolve an object.

Take Cassini ISS looking at Titan, for instance. You can do the calculation that you describe, and calculate the pixel scale. But no matter how small the pixels are, you can't achieve a true resolution better than 1 km. The atmospheric haze scatters too much to do any better.

Which is why, even with Ralph's discussion, I am still convinced that with 300m properly-sampled RADAR "pixels", the RESOLUTION is ~750m.

- Jason