SPEX Reference manual (PDF) - SRON
SPEX Reference manual (PDF) - SRON
SPEX Reference manual (PDF) - SRON
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118 Response matrices<br />
Figure 7.1: Displacement λ k as a function of the number of resolution elements R. A polynomial<br />
approximation is given in the text.<br />
Table 7.6: Coefficients for the approximations for λ k and c α<br />
i a i b i<br />
0 0.1342 1.3596<br />
1 -0.3388 4.0609<br />
2 0.7994 -4.3522<br />
3 -1.1697 5.2225<br />
4 0.9053 -3.7881<br />
5 -0.2811 1.1491<br />
7.3.8 Examples<br />
Let us apply the theory derived before to some specific line spread functions. First we consider a Cauchy<br />
(or Lorentz) distribution, given by<br />
f(x) =<br />
a<br />
π(a 2 +x 2 ) , (7.30)<br />
where a is the width parameter. The FWHM equals 2a. Next we consider the Gaussian distribution,<br />
given by<br />
f(x) = 1 √<br />
2πσ<br />
e −x2 /2σ 2 , (7.31)