For each SWS AOT calculation the procedure is
first to determine in which AOT band the desired spectral region occurs;
secondly to calculate the detector reset time 
necessary to reach
the desired SNR; and thirdly to determine the number of
integrations necessary to cover the desired wavelength region.
To this cause it is necessary to carefully read the previous chapters,
and in particular to take notice of
- the AOT band structure given in
Tab. 2.1 (p. 
)
- chapter 3 in full,
- noise parameters as given in
Tab.5.2 (p. ) and
Tab.5.3 (p. ), and
- spectral response figures as given in
Fig. 5.3 (p. ) to
Fig. 5.8 (p. ) and
Fig. 5.10 (p. ).
Tab. 6.3 (p. )
describes details of each SWS AOT.
Parameters used in this section are:
: step size in scanner steps (a resolution element covers about 6
scanner steps)
: number of samples taken from a single spectral resolution element
: number of scans
: number of steps
: dark current noise
: detector read noise
: shot noise
R: nominal grating mode resolution
S: signal strength in 
V/s
: source flux density in Jy
SNR: signal-to-noise ratio
: detector reset time in sec
Some general points of interest are:
- per AOT up to 64 observations can be requested. If more observations
are desired, an additional AOT request has to be defined;
- in all AOT's
simultaneous use of SWS LW and SW sections is arranged automatically;
- at the ISO observatory, before execution of an F-P AOT, a correction
of the radial velocity for the projected component
of the earth's orbital motion is introduced ;
- where peak flux density estimates are requested, they are needed to
select amplifier gain settings. A factor of four in accuracy is
sufficient to prevent saturation;
- observers are charged for the total time for execution of each
AOT. This so-called Target Dedicated Time (TDT) includes actual on-source integration time, overheads for internal
calibrations (excluding wavelength calibration), and satellite overheads for
slewing and pointing;
- all wavelength calibrations are scheduled separately by the Science
Operations Team.