Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/ftp/instrument_news/FOS/pub/fos_isr099_a.txt Дата изменения: Wed Oct 11 23:48:21 1995 Дата индексирования: Sun Dec 23 05:13:09 2007 Кодировка: Поисковые слова: john glenn

FOS Instrument Science Report 099

"Serendipitous Background Monitoring of the Hubble Space Telesope's Faint
Object Spectograph" by John E. Fitch and Glenn Schneider

Abstract excerpted from the report:
The nature of the Hubble Space Telescope's (HST) low Earth orbit
imposes scheduling restrictions and imterruptions in the data collection
periods for it's compliment of scientific instruments. During many of
these times the Faint Object Spectograph (FOS) is in full operational
configuration and is taking detector background measurements which are
continually reported in HST's engineering telemetry stream. These data
are primarily used to monitor the instrument for changes in behavior
resulting, principally, from intermittently noisy diodes in its digicon
arrays. These same data may be used to monitor teomporal changes in the
charged particle environment of HST's near earth orbit.

We present here the results of a study of two years of on-orbit FOS
background data obtained serendipitously during periods while the FOS
in an operational state, but not exposing on external, or calibration
targets. These in situ data, which represent more than 100,00 discrete
samples (equivalent to more than 1100 orbits) have allowed us to
accurately measure variations in the background proton flux seen by the
FOS. An analysis of these variations have pernitted us to model the
geomagnetic environment of the South Atlantic Anomaly (SAA) as a
function of time as well as the change in detector background as a
function of geomagnetic latitude.


For more information, please contact the above authors.