Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.asc.rssi.ru/RadioAstron/software/fakerad/ver_14/readme.txt Дата изменения: Wed Jan 23 11:58:19 2013 Дата индексирования: Sun Feb 3 10:23:06 2013 Кодировка: Поисковые слова: южная атлантическая аномалия

Some notes on the "FAKERAT" software.

The FAKERAT represents new branch of FAKE software
developments started in 1979 by T.J.Pearson (caltech) to
support simulations of ground-based VLBI experiments.
In 1983 D.L.Meier (JPL) added the ability to simulate
space VLBI experiments as part of the QUASAT mission
studies. In 1989/1990 D.W.Murphy (JPL) added the VSOP
spacecraft constraints since they have a major
impact of the science return from this missions. The program
with the spacecraft constraints and several additional
features was subsequently renamed fakesat.
In oder to make fakesat easier to run for those inexperienced
in using fake, an interactive interface, fakesat_menu, was
written in 1993 by D.W.Murphy. Fakesat_menu works by creating
a C shell script, .fakesat-tmp.csh, which contains all the
commands necessary tu run fakesat. This script is then
executed automatically as a background process.

We continued these developments by creating a new branch of
the software connected with RadioAstron mission; we call
this version as "FAKERAT". Because of moon-perturbed nature
of RadioAstron orbit it is impossible to use simple Kepler
approximation. Instead, interpolated table of state vectors
will be used. Therefore, fakesat orbit block was completely
replaced.
Second, RadioAstron spacecraft attitude control system imposes
particular constraints different from those applied in VSOP
mission. Therefore, software section connected with the analysis
of such constraints was essentially rewritten. Other modifications
were related with peculiarities of visualization connected
with long period RadioAstron orbit. In a given version of
the FAKERAT only one RadioAstron spacecraft may be treated,
while a formal field for VSOP exists.

What does this mean?

If one would edit manually "menu_defaults" file he must modified
VSOP field as well, to keep interface running. Such occasion
may happen when adding or deleting radio telescopes or tracking
stations to the corresponding list. It is a pity to note that
any mistakes in such modifications could lead to process crash.
Therefore, we recommend to keep saved "menu_defaults" file for
such an occasion. We plan to improve FAKERAT software in a future
to exclude such situations. We also plan to recover next options:
source view, sat view, telemetry ant, modelfit, modplot, visplot
dirty beam and clean map.

We are grateful to Dave Murphy for his kind permission to use
"fakesat" as a basis for "FAKERAT" package. We also use in
considerable volume his User's Guide for the package. Without
such a basis independent development of such scheduling software
would take much longer time, if it were possible at all.