Data Characteristics

The following text and plots describe the general data characteristics of the missions and instruments included within the MAST archive. (Clicking on the plot thumbnails below will display the entire plot.)

1. File Formats

Almost all of the archived data sets are stored using the Flexible Image Transport System (FITS) format. A description of the FITS format can be found in two online documents:

• NOST FITS Standard (NOST 100-2.0, March 29, 1999)
• FITS User's Guide (version 4.0, April 14, 1997)

Additional information on FITS can be obtained from the FITS Support Office. Information on specific file formats used in the MAST archive can be found in the documentation links listed on each MAST mission page.

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2. Spectral Data Characteristics:
Wavelength Range of Spectroscopic Data: (ps file)	Magnitude Range versus Spectral Resolution: (ps file)

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3. Image Data Characteristics:
Field of view for HST imaging detectors*: (ps file)	Minimum Detectable Flux versus wavelength for Survey Missions: (ps file)

* Note: the listed limiting magnitudes are approximate and generally refer to a one-hour integration and a signal-to-noise ratio of 10.

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