Center for Astrophysical Research in Antarctica
CARA Science:
The Bottom Line: Site Characterization Statistics
Infrared
Sky emission abouve the South Pole in µJy
arcsec
, from
1.5-2.5 µm (upper) and 2.9-4.1 µm (lower), obtained
with 1% spectral resolution through the IRPS CVF. These are the
median of all the "darkest sky" spectra obtained during the winter
of 1995. Calibration
was performed using a black body source at 0 degrees Centigrade, and fluxes
short of 2.1 µm use a nominal clibration factor for the instrument. Note
that the upper plot uses a linar, and the lower plot a log, intensity scale.
For more information, see
Phillips et al. 1999.
Submillimeter
Saturation PWV at Pole, 1961-1998. Quartiles of saturation-point
PWV distribution during the winter (day-of-year 100-300) for 1961-1998,
calculated from balloon-borne pressure and temperature measurements.
This figure illustrates the long-term stability of the South Pole
climate. Note that these saturated values are the maximum possible PWV.
"Good" observing days more than 75% of the time.
For more information, see the site testing section of
the Stark et al.
decadal report.
Millimeter
The cumulative distribution function of brightness
fluctuation power for the Python data.
Two distributions are shown, one for
unbinned data files taken over a few minutes (solid line), and one for
the data binned in 6 hour intervals (dash-dot line). The unbinned data
files are adequate to determine the 50% and 75% quartiles, but the 6
hour binned cumulative distribution function is needed to achieve
adequate signal-to-noise to estimate the 25% quartile. The increased
fraction of high fluctuation power data in the 6 hour binned
cumulative distribution function results from binning brief periods of
high fluctuation power together with periods of low fluctuation
power. The quartiles are 0.20, 0.51 and 1.62
mK
(before
compensating for instrumental effects).
For more information, see
Lay and Halverson
1999.
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Last modified Friday, 09-Apr-1999 11:09:53 CDT
http://astro.uchicago.edu/cara/research/site_testing/final.html