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: http://www.naic.edu/~astro/guide/node12.html
Дата изменения: Wed Feb 22 23:35:12 2012 Дата индексирования: Tue Oct 2 02:44:38 2012 Кодировка: |
Continuum observing at Arecibo can be made in two ways. Firstly, via
square-law detectors, passing the output of
these through integrators, and then recording the signal as a time
series via the Radar Interface (RI). The RI consists of 
-bit Analog-Digital converters, a fifo buffer memory, packer,
multiplexer, and control system. This can take dual-polarization data
at a 10-MHz rate with quantization at 2 bits, or at slower rates with
higher level quantization. To use this option, the user needs to
set up the last part of the signal path manually via cables. The
detailed procedure for this can be found in Astronomy User's Manual and
is available via the link at http://www.naic.edu/~astro/continuum.shtml.
Secondly, the data can be recorded via a spectral-line specdtrometer, and the measurements treated as spectral-line observations in which the spectral channels are subsequently collapsed across frequency during data analysis to give a broad-band continuum signal. This has the great advantage that radio interference can be edited out before the broad-band signal is derived.