Changes between Initial Version and Version 1 of SpectralRange

Timestamp:

06/09/05 12:26:04 (20 years ago)

Author:

joe

Comment:

--

SpectralRange

@@ +1 @@
+== Spectral Range ==
+
+The electromagnetic wavelength interval or equivalent over which
+observations are made is the fundamental discriminator among many
+types of solar image and other data.  The model needs to apply to both
+narrow-band ("monochromatic" or single-line) and broad-band data.
+Different branches of the field use different units depending on their
+spectral band -- frequency at the lowest ranges (of frequency), wavelength
+at intermediate ranges, energy at the highest.  Again for the sake of
+simplicity we define a single model, assuming that the necessary
+conversions can be simply made.
+
+
+
+==== Wave_Type ====
+
+
+  type: ''menu''[[BR]]
+  FITS keyword: ''WV_TYPE''[[BR]]
+
+  The class of spectral data, relating to both the nominal spectral
+bandpass and the spectral target.  Three values are recognized:
+
+  ''' broad '''
+
+
+    Indicates that the spectral range of the measurement is large
+compared to the width of absorption/emission lines within the range,
+and encompasses multiple lines as well as continuum (unless blanketed)
+
+  ''' line '''
+
+
+    The spectral range of the measurement is of the same order or less
+than the width of the target line, and is centered on a wavelength within
+the wings of the line.
+
+  ''' narrow '''
+
+
+    The spectral range of the measurement is of the same order or less
+than the typical width of lines in the neighborhood, but is centered on
+a continuum wavelength, outside of any significant lines.  This designation
+is used to distinguish narrow-band continuum (or "white-light") data from
+true broad-band data.  For data of this description, the matching spectral
+range should be much broader than the instrumental bandpass, on the
+understanding that the data are proxies for broadband measurements.
+
+The exact definition of the bandpass (''e.g.'' FWHM) is not prescribed,
+but is left up to the terminology of the data provider.  In the absence of
+a provider definition, FWHM should be used.
+
+
+==== Wave_Minimum ====
+
+
+  type: ''number''[[BR]]
+  unit: ''Ångström (10nm)''[[BR]]
+  FITS keyword: ''WV_MIN''
+
+==== Wave_Maximum ====
+
+
+  type: ''number''[[BR]]
+  unit: ''Ångström (10nm)''[[BR]]
+  FITS keyword: ''WV_MAX''
+
+  The nominal minimum (maximum) of the observing spectral bandpass
+associated with the data.  As discussed above, for narrowband continuum
+data, the range should be much larger than the instrumental bandpass;
+it should correspond to the spectral range over which the data are
+useful as a proxy, typically an octave or more.
+
+
+==== Wave_Bands ====
+
+
+  type: ''number''[[BR]]
+  FITS keyword: ''WV_NBAND''[[BR]]
+
+  The number of wavelength bands in the observation
+
+
+==== Wave_Step ====
+
+
+  type: ''number''[[BR]]
+  unit: ''Ångström (10nm) / pixel''[[BR]]
+  FITS keyword: ''WV_STP''[[BR]]
+
+  The spectral dispersion