[asac] DSB vs SSB option

[Stephane Guilloteau]

Please, look at the following document on DSB vs SSB

http://iraux2.iram.fr/~guillote/alma/dsb-ssb-guilloteau.ps

It differs from T.Hasegawa document because I consider that in continuum
mode
(or in multiple spectral line mode with spectral lines coming from opposite
sidebands)
DSB receivers can recover an extra sqrt(2) sensitivity factor because you
effectively collect
twice the bandwidth. This of course is a possible gain which can be factored
out only if
the effective fraction of projects requiring such a mode is known.

The agreed upon value for bandwidth, 4 or 8 GHz, is still a matter of
debate, essentially because we do not have sufficiently well proven design
for 8 GHz bandwidths, while we have proven designs for 4 GHz.

However, I agree with Tetsuo on the fact that the issue is too complicated
for the time being, and should be deferred to another teleconf given the
other agenda items.

    Stephane