Extinction Monitor Simulations
Rick Kessler (U. Chicago) has run some simulations of the statistical
accuracy we might expect to obtain in measuring the atmospheric
extinction using a multiple-bandpass filter on the SNIFS imager.
Figure 1 shows the RMS
extinction determination assuming 50 stars per field measured with
signal-to-noise of 100; the cases for 5 or 7 sub-filters are
presented. These calculations assume that the spectral slope (color)
between adjacent bandpasses has been measured.
The upper half of Figure 2
shows the atmospheric components that went into the model,
while the lower half shows the assumed filter bandpasses relative to
the atmospheric components. Rayleigh extinction is the solid black
curve, aerosals are represented by the dashed black line, H2O is in
blue, ozone is cyan, and O2 is in red. No attempt has been made to
measure the O2 absorption bands at 6900A and 7600A using this
technique; they are shown to indicate regions the filters must avoid in
order to obtain a clean signal for the other components.
Greg Aldering (email@example.com)
last updated Apr 24, 2002