new THEMIS color releases, Images showing color variations. Options

[DDAVIS]

First of a new series:

http://themis.asu.edu/zoom-20060622a

[edstrick]

A FUNDAMENTAL problem pushing Mars camera designers toward pushframe systems is the relatively low light levels and low to very low contrast levels of surface imaging at moderate to low sun angles through that hazy atmosphere. The dwell-time of a single-pixel-wide, gadzillion-pixels-long detector's pixels on the surface is "NanoSized" as the resolution of the camera gets "SuperSized".

A pushframe system, perfectly (to a subpixel scale) perpendicular to the moving field-of-view, multiplies that dwell time by the number of pixels the detector is wide. Signal-to-noise ratio goes from c__p to good or realliy fine. That's particularly important for color work on a low-color-contrast (in many areas) planet.

Whatever lead to the multiple internal reflection problems and whatever else is wrong or marginal in the Themis camera, seems to be fixed or avoided in ouir spiffy new "Ancient-Martian-Astronauts-Espionage-Orbiter" ... oops... I mean Mars Reconnaisance Orbiter's supercam. The test images taken under unfavorable conditions show vanishingly small brightness or color artifacts in the released data (made using preflight or first-draft inflight calibration files and software). You can see some stitching-errors in the overlaps between adjacent CCD's in the multi-detector system, but that's not bad at all for first-try tests.

[mcaplinger]

A pushframe system, perfectly (to a subpixel scale) perpendicular to the moving field-of-view, multiplies that dwell time by the number of pixels the detector is wide.

I think you're confused. What you're describing is called Time Delay Integration or TDI, and has nothing to do with pushframe, which is a multispectral technique. It's true that these can be combined, but I don't know of that being done in any previous flight instrument (though our JunoCam instrument will do it to a limited degree.)