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Notice to COS Users about FP-POS
An error has been found in the COS Instrument Handbook about the direction of
spectral shifts when the FP-POS Optional Parameter is employed. This error
should only concern observers who devise their own FP-POS sequences or use
individual FP-POS values to place spectral features at specific locations on a
detector. The Handbook states that increasing FP-POS number (FP-POS=1, 2, 3, 4)
moves the spectral range on the detector to longer wavelengths. The direction
is opposite to this. An FP-POS=1 step shifts the central wavelength to a larger
value, and FP-POS=4 to a smaller one. Thus for FP-POS=AUTO, the observer will
obtain two exposures centered at longer wavelengths (FP-POS=1, 2), one at
shorter (FP-POS=4), and one at the nominal central wavelength (FP-POS=3). Note
that the overhead timing of mechanism motions as given in Table 9-4 does not
change. Increasing FP-POS position requires 3 seconds of overhead, while moving
to smaller FP-POS positions takes 70 seconds. Observers who may be affected by
the error in sign convention should contact their PCs and resubmit their Phase
II proposals.
New ETC Release Notes (June 27, 2008)
Global screening limit for Imaging and Imaging Target Acquisition ETCs.
ETC 17.2
updates and
pending work (June 02, 2008)
New ETC Release Notes (May 27, 2008)
Known issues and features.
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