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OCR for page 329
329
used cleverly with carefully planned observing programs,
is probably adequate for both applications, although high-
bandwidth lines are extremely desirable. With a 56-kbps
line, it may prove cost-effective to operate telescopes
from remote locations in some cases. For example, the
University of California is investigating the possibility
of operating a proposed 10-m telescope, located on Mauna
Kea, from a control center in California. If remote
operation saves only a few round trips per month between
Hawaii and California, a net cost savings will be
achieved. In the case of the second application, the
Panel believes that an observatory operating its tele-
scopes with remote observer participation must take
responsibility for the terminal at the observer's end of
the data link. The costs of such a scheme would there-
fore be substantially greater than the costs of the
communication service alone and will probably prohibit
the implementation of this concept in the 1980's.
I X. SPECIALI ZED ARCHITECTURES
The Panel investigated the possibility that specialized
computer architectures might lead to dramatic improve-
ments in astronomical computing. For example, one might
imagine a cubical n X n X n array of microprocessors,
each able to transfer data to and from its six nearest
neighbors and all synchronized by a master oscillator.
Such an array would seem to be ideal for some kinds of
hydrodynamical calculations and would reduce the computa-
tion time by a factor of n3 since n3 operations are
performed in parallel. If the top and bottom, left and
right, and front and back sides of the array were con-
nected, the architecture could be adapted to N-body
calculations with n3 particles (one per processor).
There are, in fact, several specialized architectures
being investigated and/or implemented. NASA/Goddard Space
Flight Center is developing the Massively Parallel Proces-
sor (MPP), which will contain a 128 X 128 array of proces-
sors, each connected to its nearest neighbors on the top,
bottom, left, and right. Each processor will be capable
of performing only simple functions.
The MPP is intended
to be used for pipeline processing of Landsat images. It
is an interesting development in that the physics of the
problem is embodied in the computer architecture.
NASA/Ames is developing a specialized computer to be
used in hydrodynamic calculations. The emphasis here is
Representative terms from entire chapter:
specialized computer
