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AtmosphereDR.Atmosphere HistoryHide minor edits - Show changes to output October 22, 2008, at 17:38 CET
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- Changed line 16 from:
So, a logarithmic plot of the fluxes (divided by the intrinsic spectra) versus airmasses gives a straight line with a slope that corresponds to the atmospheric absorption. One can then interpolate the extinction at a certain airmass. to:
So, a logarithmic plot of the fluxes (divided by the intrinsic spectra) versus airmasses gives a straight line with a slope that corresponds to the atmospheric absorption. One can then interpolate the extinction at a certain airmass. This is done in [[RRT | Roy's Reduction Tools]]. August 29, 2008, at 20:46 CET
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- Added lines 1-16:
Consider a source {$S_1$} with intrinsic spectrum {$I_{0,1}$} and a source {$S_2$} with intrinsic spectrum {$I_{0,2}$}. The fluxes measured on the atmosphere will be {$S_1 = I_{0,1} R_{\nu} \exp^{-A_{\nu} am_1}$} {$S_2 = I_{0,2} R_{\nu} \exp^{-A_{\nu} am_2}$} where {$R_{\nu}$} is the frequency-dependent response of the telescope, {$A_{\nu}$} the frequency-dependent atmospheric absorption and {$am_1$}, {$am_2$} are the airmasses at which the two sources are observed. Then {$\frac{S_1}{S_2} = \frac{I_{0,1}}{I_{0,2}} \exp^{-A_{\nu} (am_1 - am_2)}$} and thus {$\log\left(\frac{S_1}{S_2}\right) = - \log\left(\frac{I_{0,1}}{I_{0,2}}\right) \cdot A_{\nu} (am_1 - am_2)$} So, a logarithmic plot of the fluxes (divided by the intrinsic spectra) versus airmasses gives a straight line with a slope that corresponds to the atmospheric absorption. One can then interpolate the extinction at a certain airmass. |