Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://www.naic.edu/~nolan/radar/
Дата изменения: Thu Feb 24 23:09:07 2005 Дата индексирования: Mon Oct 1 23:58:16 2012 Кодировка: Поисковые слова: п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п п |
A major component of the upgraded telescope is the installation of a new 1 megawatt 12.6 cm radar system, which has been totally funded by NASA. This instrument will enable the Observatory to detect asteroids over a very much wider radial range than with the old 420 kilowatt system. We anticipate as much as a factor 40 improvement in sensitivity from the Gregorian Upgrade (and in no case less than a factor of 14). Some of this comes from the increase in transmitter power, some from the improvement in the optics of the telescope, and some from the greatly increased zenith angle range with constant sensitivity that the new ground screen bestows.
Available equipment includes a 12.6 cm (2380 MHz) dual-polarization maser receiver with the capability of both complex voltage sampling and a new, high throughput, radar decoder. Sampling has a limit of 10 MHz, while the decoder can operate at up to 20 MHz (7.5m range resolution).
I will try to keep the status of the S-Band radar up to date, but please note the modification dates, as these things tend to get left behind.
Here are some recent images of asteroids obtained with the Arecibo Planetary Radar.
The following links give some results from previous observations. Most of these are just preliminary images, reduced immediately after the observations, and are not "final" results.
The following data were taken by various observers using the Arecibo Observatory 12.6 cm radar.
See also Steve Ostro and Keith Rosema's Asteroid Radar Research pages.
I have a figure showing the
observability of asteroids (at Arecibo Observatory) over the
first years. A number of wild assumptions were used in making
this figure, so take the absolute values with a
grain of salt.
We have the IAUCs and MPCs from the Central Bureau for Astronomical Telegrams (CBAT), and the Minor Planet Center (but only accessible from the observatory; others should contact the Minor Planet Center for subscription information).
The data acquisition hardware has been
mostly designed and partly built. The software depends on
some details of that hardware that have not been finalized.
For reference, the documentation for the old CW acquisition
software, NURAD
is
available.
I'm formulating a list of implementation and testing tasks, though these will change with time (and review).
I'm working on the header information. I'm not done yet...
And there's the Observing Chacklist.
Chris De Vries wrote a description of how to reduce planetary radar data, using the 1988 Venus data taken at the Arecibo Observatory as a model. This list consists primarily of manual pages in PostScript®, but is offline at the moment.
Steve
Ostro and Keith Rosema have an Asteroid page with
descriptions and images from historical and possible future
asteroid radar observations.
Scott
Hudson has a (largely radar-based) asteroid
page, including images and models of 4679
Castalia (1989 PB) and 4179
Toutatis.
Last update: $Date: 1997/11/18 20:17:48 $.