Spectral Line Observing guide:
A guide for new ( and not so new ) users.
Covers basic concepts, techniques, calibration (for more recent
results see the links below) and data reduction. Note that this has
not yet been updated for observing with ACSIS. HTML and
Average spectra: These are the average of spectra
observed with the ACSIS backend under variable conditions, and judged to
be of acceptable quality. Until now there are
RxA3 spectra available.
Main beam efficiencies have been derived from
all ACSIS observations made with RxA3 and HARP at 230.538 and 345.796 GHz of the planets Mars,
Jupiter, and Uranus.
Planetary flux data
can also be used for calibration.
Older (before early 2006) DAS measurements and utilities that may still be useful:
These typically were taken with the DAS backend under controlled
conditions during a special campaign several years ago . Although
of good quality, systematic differences with newer receivers
warrant caution. All receivers used have been retired since: B3,
A2, B3i, and C2.
spectra: These were also taken a few years ago and aimed
to complement the standard spectra by adding data on
non-standard, but frequently used frequencies. They were selected
by hand as deemed 'representative', at a time that averaging large
numbers of spectra was not common practice. Some frequencies are
not very representative due to a lack of data. All receiver used
have been retired or upgraded since: A3, B3, WC and WD
A web interface to our (DAS) standard spectra database is
available, as is an interface to the (DAS)
These databases contain all observations of standard sources and planets,
and derived aperture and beam efficiencies
Beam efficiencies are discussed for
DAS observations made of Mars, Jupiter, and Uranus with RxA3i, RxB3, RxW-C, and RxW-D.
Results of Moon measurements and derived
Moon efficiencies are given here.
For archival DAS data, one can use the plot-standard
command inside SPECX to see how an observation of a standard source
compares with the true "standard", if a standard spectrum is
You can calculate the LSR Velocity
to see if the telluric line might interfere with your observation if
you are doing frequency switching (use topocenctric velocity for IAU
Standard Solar Motion and multiply velocity with -1.0).