Instrument Overview:
NICMOS is an HST Axial Replacement Instrument, containing three
cameras designed for simultaneous operation. The NICMOS optics
present the detectors with three adjacent, but not spatially contiguous
Fields-of-View of different image scales. NICMOS employ three low
noise, high Quantum Efficiency, HgCdTe 256x256 Focal Plane Arrays in a
passive dewar using solid N2 as a coolant.
NICMOS
provides spectral coverage in the range of 0.8 to 2.5 microns, and
contains a variety of Filters, GRISMS, and polarizers. Each camera carries a
complement of 19 of these optical elements, selected through three
independent Filter Wheel Mechanisms. Grism spectroscopy, in the widest
field camera (number 3) provides a multi-object spectrographic
capability with a resolution of ~200. A 0.3 arc-second radius occulting spot,
and optimized cold mask, in the intermediate resolution camera (number 2)
provides a Coronographic Imaging Capability . The NICMOS Fore-Optics
Assembly fully corrects the spherically aberrated HST input beam.
NICMOS achives diffraction limited performance in the high resolution
camera (number 1) to 1.0 microns, and in camera 2 to 1.75 microns. An
internal Field-Offset Mechanism allows NICMOS to observe
background fields and in parallel with other HST instruments without the
necessity of re-pointing the spacecraft.
STScI's
Main
NICMOS page,
Instrument Science Reports,
Reference Files.
GSFC NICMOS Cooling System page
HST European Coordinating Facility (ECF)
- source for grisim software.
UofA NICMOS
database
page.