Brian Jackson edited To_understand_the_figure_consider__.tex  almost 9 years ago

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To understand the figure, consider $\log_{\rm 10} \left( P_{\rm act} \right)$ fixed at $0$. 0.  For smaller and smaller $\log_{\rm 10} \left( P_{\rm obs} \right)$, the probability density increases. This result comports with our intuition: the observed pressure signal is likely to fall below the actual pressure well at the center of the devil since the devil is unlikely to pass directly over the sensor. Taking instead $\log_{\rm 10} \left( P_{\rm obs} \right)$ fixed at $0$, 0,  the probability density increases for larger and larger $\log_{\rm 10} \left( P_{\rm act} \right) = 0$, =$ 0,  indicating that an observed pressure is more likely to have come from a distant dust devil with a large central pressure well than one passing nearby with a small central well. Thus, the miss distance effect can significantly skew the observed distribution of pressure signals away from the actual distribution. Figure \ref{fig:} shows how, using the example of a distribution of $P_{\rm act}$-values uniformly spread between $P_{\rm min} =$ 0.1 and $P_{\rm max} = $10 hPa (blue line). Using the probability density described above, we can see that the probability $Pr$ for $P_{\rm obs}$ to lie between $P_{\rm min}$ and some value $x \le P_{\rm act}$ is given by   \begin{equation}  Pr(P_{\rm obs} \le x) = P_{\rm act} \int_{\rm P_{\rm min}}^{x} \left( \dfrac{dx}{x^2} \right)  \end{equation}