- Timestamp:
- 01/05/05 16:13:21 (20 years ago)
- Location:
- trunk/MagicSoft/TDAS-Extractor
- Files:
-
- 2 edited
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trunk/MagicSoft/TDAS-Extractor/Algorithms.tex
r5708 r5709 120 120 The following free adjustable parameters have to be set from outside: 121 121 \begin{description} 122 \item[Window sizes:\xspace] Independent y for high-gain and low-gain (default: 6,6)122 \item[Window sizes:\xspace] Independently for high-gain and low-gain (default: 6,6) 123 123 \end{description} 124 124 … … 246 246 \end{equation} 247 247 248 where $\Delta T_{\mathrm{FADC}} = 3.33$ ns is the sampling interval lof the MAGIC FADCs.248 where $\Delta T_{\mathrm{FADC}} = 3.33$ ns is the sampling interval of the MAGIC FADCs. 249 249 250 250 … … 253 253 The electronics noise is largely white, uncorrelated in time. The noise from the night sky background photons is the superposition of the detector response to single photo electrons arriving randomly distributed in time. Figure \ref{fig:noise_autocorr_AB_36038_TDAS} shows the noise autocorrelation matrix for an open camera. The large noise autocorrelation in time of the current FADC system is due to the pulse shaping with a shaping constant of 6 ns. 254 254 255 In general the amplitude and timing weights, $\boldsymbol{w}_{\text{amp}}$ and $\boldsymbol{w}_{\text{time}}$, depend on the pulse shape, the derivative of the pulse shape and the noise autocorrelation. In the high gain samples the correlated night sky background noise dominates over the white electronics noise. Thus different noise levels just cause the noise autocorrelation matrix $\boldsymbol{B}$ to change by a factor, which cancel ls out in the weights calculation. Thus in the high gain the weights are to a very good approximation independent of the night sky background noise level.255 In general the amplitude and timing weights, $\boldsymbol{w}_{\text{amp}}$ and $\boldsymbol{w}_{\text{time}}$, depend on the pulse shape, the derivative of the pulse shape and the noise autocorrelation. In the high gain samples the correlated night sky background noise dominates over the white electronics noise. Thus different noise levels just cause the noise autocorrelation matrix $\boldsymbol{B}$ to change by a factor, which cancels out in the weights calculation. Thus in the high gain the weights are to a very good approximation independent of the night sky background noise level. 256 256 257 257 Contrary to that in the low gain samples ... . … … 268 268 269 269 270 Using the average reconstructed pulpo pulse shape, see figure \ref{fig:pulpo_shape_low}, and the reconstructed noise autocorrelation matrix from a pedestal run with random triggers, the digital filter weights are computed. Figures \ref{fig:w_time_MC_input_TDAS} and \ref{fig:w_amp_MC_input_TDAS} show the parameterization of the amplitude and timing weights for the MC pulse shape as a fu ction of the ...270 Using the average reconstructed pulpo pulse shape, see figure \ref{fig:pulpo_shape_low}, and the reconstructed noise autocorrelation matrix from a pedestal run with random triggers, the digital filter weights are computed. Figures \ref{fig:w_time_MC_input_TDAS} and \ref{fig:w_amp_MC_input_TDAS} show the parameterization of the amplitude and timing weights for the MC pulse shape as a function of the ... 271 271 272 272 … … 275 275 \includegraphics[totalheight=7cm]{w_time_MC_input_TDAS.eps} 276 276 \end{center} 277 \caption[Time weights.]{Time weights $w_{\mathrm{time}}(t_0) \ldots w_{\mathrm{time}}(t_5)$ for a window size of 6 FADC slices . The first weight $w_{\mathrm{time}}(t_0)$ is plotted as a fuction of the relative time $t_{\text{rel}}$ the trigger and the FADC clock in the range $[-0.5;0.5[ \ T_{\text{ADC}}$, the second weight in the range $[0.5;1.5[ \ T_{\text{ADC}}$ and so on. A binning resolution of $0.1 T_{\text{ADC}}$ has been chosen.} \label{fig:w_time_MC_input_TDAS}277 \caption[Time weights.]{Time weights $w_{\mathrm{time}}(t_0) \ldots w_{\mathrm{time}}(t_5)$ for a window size of 6 FADC slices for the pulse shape used in the MC simulations. The first weight $w_{\mathrm{time}}(t_0)$ is plotted as a function of the relative time $t_{\text{rel}}$ the trigger and the FADC clock in the range $[-0.5;0.5[ \ T_{\text{ADC}}$, the second weight in the range $[0.5;1.5[ \ T_{\text{ADC}}$ and so on. A binning resolution of $0.1 T_{\text{ADC}}$ has been chosen.} \label{fig:w_time_MC_input_TDAS} 278 278 \end{figure} 279 279 … … 282 282 \includegraphics[totalheight=7cm]{w_amp_MC_input_TDAS.eps} 283 283 \end{center} 284 \caption[Amplitude weights.]{Amplitude weights $w_{\mathrm{amp}}(t_0) \ldots w_{\mathrm{amp}}(t_5)$ for a window size of 6 FADC slices . The first weight $w_{\mathrm{amp}}(t_0)$ is plotted as a fuction of the relative time $t_{\text{rel}}$ the trigger and the FADC clock in the range $[-0.5;0.5[ \ T_{\text{ADC}}$, the second weight in the range $[0.5;1.5[ \ T_{\text{ADC}}$ and so on. A binning resolution of $0.1 T_{\text{ADC}}$ has been chosen.} \label{fig:w_amp_MC_input_TDAS}284 \caption[Amplitude weights.]{Amplitude weights $w_{\mathrm{amp}}(t_0) \ldots w_{\mathrm{amp}}(t_5)$ for a window size of 6 FADC slices for the pulse shape used in the MC simulations. The first weight $w_{\mathrm{amp}}(t_0)$ is plotted as a function of the relative time $t_{\text{rel}}$ the trigger and the FADC clock in the range $[-0.5;0.5[ \ T_{\text{ADC}}$, the second weight in the range $[0.5;1.5[ \ T_{\text{ADC}}$ and so on. A binning resolution of $0.1 T_{\text{ADC}}$ has been chosen.} \label{fig:w_amp_MC_input_TDAS} 285 285 \end{figure} 286 286 … … 293 293 \end{equation} 294 294 295 for all possible signal start slices s $i_0$. Let $i_0^*$ be the signal start slice with the largest $e_{i_0}$. Then in a seconststep the timing offset $\tau$ is calculated:295 for all possible signal start slices $i_0$. Let $i_0^*$ be the signal start slice with the largest $e_{i_0}$. Then in a second step the timing offset $\tau$ is calculated: 296 296 297 297 \begin{equation} … … 299 299 \end{equation} 300 300 301 and the weig ths iterated:301 and the weights iterated: 302 302 303 303 \begin{equation} … … 339 339 \includegraphics[totalheight=7cm]{time_sliding.eps} 340 340 \end{center} 341 \caption[Digital filter weights applied.]{Digital filter weights applied .} \label{fig:amp_sliding}341 \caption[Digital filter weights applied.]{Digital filter weights applied to the recorded FADC time slices of one calibration pulse. The left plot shows the result of the applied amplitude weights $e(t_0)=\sum_{i=0}^{i=n-1} w_{\mathrm{amp}}(t_0+i \cdot T_{\text{ADC}})y(t_0+i \cdot T_{\text{ADC}})$ and the right plot shows the result of the applied timing weights $e\tau(t_0)=\sum_{i=0}^{i=n-1} w_{\mathrm{time}}(t_0+i \cdot T_{\text{ADC}})y(t_0+i \cdot T_{\text{ADC}})$ .} \label{fig:amp_sliding} 342 342 \end{figure} 343 343 -
trunk/MagicSoft/TDAS-Extractor/MAGIC_signal_reco.bbl
r5584 r5709 1 1 \begin{thebibliography}{1} 2 3 \bibitem{Magic-PMT} 4 A.~Ostankov et~al., 5 \newblock {\em A study of the new hemispherical 6-dynodes PMT from electron 6 tubes}, 7 \newblock Nucl. Instrum. Meth. {\bf A442} (2000) 117. 8 9 \bibitem{MAGIC-analog-link-2} 10 E.~Lorenz et~al., 11 \newblock {\em A fast, large dynamic range analog signal transfer system based 12 on optical fibers}, 13 \newblock Nucl. Instrum. Meth. {\bf A461} (2001) 517. 14 15 \bibitem{MAGIC-calibration} 16 T.~Schweizer et~al., 17 \newblock {\em The optical calibration of the MAGIC telescope camera}, 18 \newblock IEEE Trans. Nucl. Sci. {\bf 49} (2002) 2497. 2 19 3 20 \bibitem{NUMREC}
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