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AOT SWS06 allows the user to observe up to 64 wavelength ranges, with
SWS in the grating mode. The wavelength range(s) may be chosen
anywhere in the SWS grating range, i.e., between 2.38 and 45.2 
m,
under the restriction that each range falls within
one of the AOT bands (Tab. 2.1,
p. 
).
The sum of the ranges chosen can cover the entire SWS wavelength range.
The spectrum is sampled in a flexible and fastest possible way.
Wavelength ranges are specified by giving the vacuum wavelengths of
beginning and end of each range, and the source's heliocentric radial
velocity . A specific wavelength within the desired
wavelength range is being referred to as the reference wavelength
of that
range. It is important that while selecting this wavelength one should avoid
lines and make sure that it is representative for the average
continuum flux density, rather than that it is close to the centre of
the wavelength range. In SWS06, reference scans are made only when the grating
scan takes longer than the nominal interval between reference scans.
AOT SWS06 is executed the following way:
The telescope is pointed to the target position. Then for each wavelength
range (or pair of merged ranges) the following sequence of steps is taken:
- A dark-current measurement is done.
- A measurement on the reference wavelength is performed, if the spectral
scan is long enough to need it.
- The wavelength range specified in the AOT is observed. Each
range is scanned back and forth to provide redundancy.
- The reference measurement (if any) is repeated.
- A dark current measurements is done.
- Very long observations are interrupted by wavelength switching to
the reference wavelength, as an additional photometric check.
- If a single up and down scan does not provide enough sensitivity,
the measurement sequence is repeated as often as necessary
- Photometric checks using the internal calibrator are done at regular
intervals, at least once per AOT.
AOT SWS06 is used for a single observation of one target.
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SWS Consortium
Wed Aug 7 17:20:29 MET DST 1996