Venus Express Options

[tedstryk]

If all goes well, Venus Express will be a major topic for discussion in this forum a year from now. Does anyone know how good the surface coverage will be from VIRTIS and VMC? My understanding is that VIRTIS will obtain low resolution multispectral maps, and that VMC will, in addition to cloud monitoring, have one channel that can see the surface, but I don't know at what resolution or at what quality. It will be nice to have some non-radar images of Venus' surface besides the Venera snapshots and the shadowy images from Earth and Galileo's NIMS.

Ted

[edstrick]

On Cassin, the VIMS is the best instrument we could design with early 90's mid-infrared imaging technology.

We now have real mid-infrared imaging detectors. Not 10 megapixel, but still real camera chips, that can take quality images with really good resolution in the mid-IR (1 to 5 micrometers, more or less). We just @#$@# didn't back then.

[JRehling]

On Cassin, the VIMS is the best instrument we could design with early 90's mid-infrared imaging technology.

We now have real mid-infrared imaging detectors.  Not 10 megapixel, but still real camera chips, that can take quality images with really good resolution in the mid-IR  (1 to 5 micrometers, more or less).  We just @#$@# didn't back then.

It seems apparent that the 938nm wavelength, which is the best one ISS has to use on Titan, is not the best penetrator of Titan's haze, and that VIMS can thereby make up for (some of) ISS's edge in intrinsic resolution by utilizing better IR wavelengths. Not only by choosing the best possible single wavelength (the best ones are longer than 938nm, at other spectral "holes"), and taking one-wavelength images in that. Surely VIRTIS will beat ISS in that respect. On the other hand, CO2 will block different holes than CH4, and I'm not sure if it leaves us a better hole than CO2 or not.


I think the best IR products of Venus's surface will come from compiling repeated coverage of the same areas and "stacking" or somehow integrating the data to average out over varying cloud thicknesses.

Finally, note that IR is complicated terribly at Venus, but not at Titan, by thermal effects. If all we see is a thermal record of the surface, then we may not get much more than crude altimetry we already knew about. Sorting out the albedo may be impossible.