[alma-config] Forwarded mail bounced by email reflector

[Al Wootten]

Date: Tue, 6 Feb 2001 13:22:11 -0700
To: Simon Radford <sradford at nrao.edu>
Cc: Darrel Emerson <demerson at nrao.edu>, "Larry D'Addario" <ldaddari at nrao.edu>,
        alma-config at nrao.edu
Subject: Re: maximum baseline
In-Reply-To: <3A805823.B2306D53 at nrao.edu>
References: <3A805823.B2306D53 at nrao.edu>
X-Mailer: VM 6.76 under Emacs 20.7.1

Simon Radford writes:
 > -- The engineers need a firm specification on the maximum fiber run. If
 > the configurations were already known, this could be derived from the
 > road layout, etc. But the configurations are still being designed while
 > the engineers already embarked some time ago on development of the fiber
 > links. Section 7.4.2 states "The longest distance to an antenna will be
 > 25 km." Subsequent sections also mention 25 km. If this is the project
 > specification, please elevate it to a more prominent place.

My understanding is that the 25 km maximum cable run is already a hard
specification, not something that we must derive from configuration
discussions.  If the maximum baseline length is 10 km, then the 25 km
includes considerable headroom, although it could all be used up if
circuitous routing turns out to be needed.  It does *not* allow for
the possibility of significant extensions to the maximum baseline
length.

I agree with Simon that the 25 km spec should be made more prominent
in the PB, and that the various other references to the array size
should be made consistent and precise.  At this stage, any proposal to
make the maximum baseline longer than 10 km should be treated as just
that -- a proposal -- until its benefits can be carefully weighed
against its costs.

--Larry