Transmission byPhilippe Rousselle
The IR100 is a longpass filter that transmits
the extreme end of the CCD sensitivity. It allows some specials
applications under very difficult conditions. Note : the
transmission after 900 nm is only estimated.
INTEREST
- Isolate some wavelenghts usually lost in the
glare of all the shorter colors
PROBLEMS
- Extremely weak quantity of light (except on
Venus) requiring solid imaging technic and the use of cameras
able to make exposures of a few seconds.
- Important loss of resolution
Mars
17 october 2005 - Mewlon 210 and Lumenera LU075M
The filter probably doesn't show different things from
the usualy IR-pass filters, but could provide interesting
atmospheric penetration in the case of big dust storms.
This was seen on HST images in 2001 at 1042 nm.
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Saturn
8 december 2004 - Mewlon 210 and ATK-1HS
The globe is darker than rings. There must be an
absorption, probably by a CH4 band near 1 micron.
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Jupiter
2 june 2006 - Mewlon 210 and Lumenera LU075M
The presence of CH4 absorption is proven by the bright
appearance of all the higher clouds (GRS, BA, zones...)
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Venus (dayside)
Enhances some very weak details (hard to see here)
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Venus (nightside)
This is maybe the most interesting use. The
filter is able to detectal the thermal emission from the
ground of the planet. More
information
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