1.2 Layout

NICMOS provides direct imaging in broad, medium, and narrow-band filters at a range of spatial resolutions in the near infrared from 0.8 to 2.5 microns, together with broad-band imaging polarimetry, coronagraphic imaging and slitless grism spectroscopy. Figure 1.1 provides a road map to navigating this document.

The chapters of this Handbook are as follows:

•	Chapter 1:Introduction and General Considerations, describes the Handbook layout, where to find help and additional documentation, and important advice for preparing NICMOS proposals.

•	Chapter 2:Overview of NICMOS, provides an introduction to the capabilities of NICMOS under NCS operations, the basic physical and imaging layout, and a summary of the detectors’ operations.

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Chapter 3:Designing NICMOS Observations, shows in tabular form the required steps for designing a NICMOS observing program, guides users through some of the technical details for choosing the optimal configuration for a given observation, and provides the reader with a “map” for the subsequent chapters.

•	Chapter 4:Imaging, provides a description of NICMOS’s imaging capabilities including camera resolutions and throughputs, image quality and effects of cosmic rays. The infrared background seen by NICMOS is also described here.

•	Chapter 5:Coronagraphy, Polarimetry and Grism Spectroscopy, provides detailed information on coronagraphic imaging, grism spectroscopy, and polarimetry.

•	Chapter 6:NICMOS Apertures and Orientation, describes the aperture definitions and the sky-projected orientation of the instrument.

•	Chapter 7:NICMOS Detectors, describes the basic properties of the detectors used in the three cameras including their physical characteristics, capabilities and limitations. Performance descriptions are based on calibrations under NCS operations.

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Chapter 8:Detector Readout Modes, explains the data taking modes which take advantage of the non-destructive readout capabilities of the NICMOS arrays. While nearly all observers will choose to use MULTIACCUM mode, we give descriptions of other modes to help proposers/users choose the most appropriate ones for their observations.

•	Chapter 9:Exposure Time Calculations, provides information for performing signal-to-noise calculations, either by using pencil and paper, or using software tools that are provided on the World Wide Web (WWW).

•	Chapter 10:Overheads and Orbit Time Determination, provides information to convert from a series of planned science exposures to an estimate of the number of orbits, including spacecraft and NICMOS overheads. This chapter applies principally to the planning of Phase I proposals.

•	Appendix A:Imaging Reference Material, provides summary information and filter transmission curves for each imaging filter, ordered by camera and increasing wavelength.

•	Appendix B:Flux Units and Line Lists, provides formulae and tables for the conversion of flux units, and a list of common infrared spectral lines.

•	Appendix C:Bright Object Mode, describes the BRIGHTOBJ read-out mode.

•	Appendix D:Techniques for Dithering, Background Measurement and Mapping, describes the implementation of a pre-defined set of patterns which accomplish dithering and chopping from the field of interest, and allow easy generation of large mosaic images.

•	Appendix E:The NICMOS Cooling System, describes the system that has cooled NICMOS since Cycle 11.

Figure 1.1: Roadmap for Using the NICMOS Instrument Handbook