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Timestamp:
03/04/05 14:26:44 (20 years ago)
Author:
gaug
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trunk/MagicSoft/TDAS-Extractor
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  • trunk/MagicSoft/TDAS-Extractor/Conclusions.tex

    r6659 r6745  
    1 \section{Conclusions}
     1\section{Conclusions \label{sec:conclusion}}
    22
    33In the past, many MAGIC analyses have been conducted using different signal extractors.
    … …  
    6060%%% mode: latex
    6161%%% TeX-master: "MAGIC_signal_reco"
     62%%% TeX-master: "MAGIC_signal_reco"
    6263%%% End:

  • trunk/MagicSoft/TDAS-Extractor/Criteria.tex

    r6666 r6745  
    1 \section{Criteria for the Optimal Signal Extraction}
     1\section{Criteria for the Optimal Signal Extraction \label{sec:criteria}}
    22
    33The goal for the optimal signal reconstruction algorithm is to compute an unbiased estimate of the strength and arrival time of the

  • trunk/MagicSoft/TDAS-Extractor/Introduction.tex

    r6648 r6745  
    22
    33
    4 The MAGIC telescope aims to study the gamma ray emission from high energy phenomena and the violent physics processes in the universe
     4The MAGIC telescope aims to study the gamma ray emission from high energy phenomena and the violent physics
     5processes in the universe
    56at the lowest energy threshold possible \cite{low_energy}.
    67
    7 Figure~\ref{fig:MAGIC_read-out_scheme} shows a sketch of the MAGIC read-out scheme, including the PMT camera,
    8 the analog-optical link, the majority trigger logic and
    9 FADCs. The used PMTs provide a very fast
     8Figure~\ref{fig:MAGIC_read-out_scheme} shows a sketch of the MAGIC read-out scheme, including the
     9photomultiplier tubes (PMT) camera,
     10the analog-optical link, the majority trigger logic and flash analog-to-digital converters (FADCs).
     11The used PMTs provide a very fast
    1012response to the input light signal. The response of the PMTs to sub-ns input light pulses shows a FWHM of
    11 1.0 - 1.2 ns and rise and fall times of 600 and 700 ps correspondingly \cite{Magic-PMT}. By modulating VCSEL
     131.0 - 1.2 ns and rise and fall times of 600 and 700\,ps correspondingly~\cite{Magic-PMT}. By modulating
     14vertical-cavity surface-emitting laser (VCSEL)
    1215type laser diodes in amplitude, the fast analogue signals from the PMTs are transferred via 162\,m long,
    131650/125\,$\mu$m diameter optical fibers to the counting house \cite{MAGIC-analog-link-2}. After transforming the
    … …  
    2528\caption[Current MAGIC read-out scheme.]{Current MAGIC read-out scheme: the analog PMT signals are
    2629transferred via an analog optical link to the counting house -- where after the trigger decision -- the signals
    27 are digitized by a 300 MHz FADCs system and written to the hard disk of a DAQ PC.}
     30are digitized by a 300\,MHz FADCs system and written to the hard disk of a data acquisition PC.}
    2831\label{fig:MAGIC_read-out_scheme}
    2932\end{figure}
    … …  
    3740resolution of 8 bit only, the signals are split into two branches with gains differing by a factor 10.
    3841One branch is delayed by 55\,ns and then both branches are multiplexed and consecutively read-out by one FADC.
    39 Figure~\ref{fig:pulpo_shape_high} shows a typical average of identical signals. A more detailed overview about the MAGIC read-out and DAQ system is given in \cite{Magic-DAQ}.
     42Figure~\ref{fig:pulpo_shape_high} shows a typical average of identical signals.
     43A more detailed overview about the MAGIC read-out and DAQ system is given in \cite{Magic-DAQ}.
    4044% The maximum sustained trigger rate could be 1 kHz. The FADCs feature a FIFO memory which allows a significantly higher short-time rate.
    4145% Obviously by doing this, more LONS is integrated and thus the performance of the telescope on the analysis level is degraded.
    4246
    4347
    44 To reach the highest sensitivity and the lowest possible analysis energy threshold the recorded signals from Cherenkov light have to be accurately reconstructed. Therefore the highest possible signal to noise ratio, signal reconstruction resolution and a small bias are important.
     48To reach the highest sensitivity and the lowest possible analysis energy threshold the recorded signals from
     49Cherenkov light have to be accurately reconstructed. Therefore the highest possible signal to noise ratio,
     50signal reconstruction resolution and a small bias are important.
    4551
    46 Monte Carlo (MC) based simulations predict different time structures for gamma and hadron induced shower images as well as for images of single muons. An accurate arrival time determination may therefore improve the separation power of gamma events from the background events. Moreover, the timing information may be used in the image cleaning to discriminate between pixels which signal belongs to the shower and pixels which are affected by randomly timed background noise.
     52Monte Carlo (MC) based simulations predict different time structures for gamma and hadron induced shower
     53images as well as for images of single muons. An accurate arrival time determination may therefore improve
     54the separation power of gamma events from the background events. Moreover, the timing information may be
     55used in the image cleaning to discriminate between pixels which signal belongs to the shower and pixels
     56which are affected by randomly timed background noise.
    4757
    4858
    49 This note is structured as follows: In section 2 the average pulse shapes are reconstructed from the recorded FADC samples for calibration and cosmics pulses. These pulse shapes are compared with the pulse shape implemented in the MC. In section 3 different signal reconstruction algorithms and their implementation in the common MAGIC software framework MARS are reviewed. In section 4 criteria for an optimal signal reconstruction are developed. Thereafter the signal extraction algorithms under study are applied to pedestal, calibration and MC events in sections 5 to 7. The CPU requirements of the different algorithms are compared in section 8. Finally in section 9 the results are summarized and in section 10 a standard signal extraction algorithm for MAGIC is proposed.
     59This note is structured as follows: In section~\ref{sec:reco} the average pulse shapes are reconstructed
     60from the recorded
     61 FADC samples for calibration and cosmics pulses. These pulse shapes are compared with the pulse shape
     62implemented in the Monte-Carlo (MC) simulation.
     63In section~\ref{sec:algorithms} different signal reconstruction algorithms and their implementation in
     64the common MAGIC software framework MARS are reviewed. In section~\ref{sec:criteria} criteria for an optimal
     65signal
     66reconstruction are developed. Thereafter the signal extraction algorithms under study are applied to
     67pedestal, calibration and MC events in sections~\ref{sec:pedestals} to~\ref{sec:mc}.
     68The CPU requirements of the different algorithms
     69are compared in section~\ref{sec:speed}. Finally in section~\ref{sec:results} the results are summarized
     70and in section~\ref{sec:conclusion} a standard signal extraction algorithm for MAGIC is proposed.
    5071
    5172\subsection{Characteristics of the current read-out system}
    5273
    53 The following intrinsic characteristics of the current read-out system affect especially the signal reconstruction:
     74The following intrinsic characteristics of the current read-out system affect especially the signal
     75reconstruction:
    5476
    5577\begin{description}
    … …  
    7799%%% mode: latex
    78100%%% TeX-master: "MAGIC_signal_reco"
     101%%% TeX-master: "Introduction"
    79102%%% End:
    80103

  • trunk/MagicSoft/TDAS-Extractor/Reconstruction.tex

    r6648 r6745  
    1 \section{Pulse Shape Reconstruction}
     1\section{Pulse Shape Reconstruction \label{sec:reco}}
    22
    33The FADC clock is not synchronized with the trigger. Therefore, the relative position of the recorded

  • trunk/MagicSoft/TDAS-Extractor/Results.tex

    r6660 r6745  
    1 \section{Results}
     1\section{Results \label{sec:results}}
    22
    33Based on the previous investigations, we summarize the obtained results in table~\ref{tab:result}. The following criteria
    … …  
    61614   & Fix Win. (8,8)     & \no & \ok & \ok &\best& \no & \ok & --  & n/a & n/a & \ok \\   
    62625   & Fix W. (14,10)     & \no & \ok & \ok &\best& \no & \ok & --  & n/a & n/a & \ok \\   
    63 \hline                                                                           
     63\hline                                                                           
    64646   & FW. Spl. (4,4)     & \ok & \no & \no & \no & \ok & \no & --  & n/a & n/a & \ok \\   
    65657   & FW. Spl. (4,6)     & \ok & \no & \no & \no & \ok & \no & --  & n/a & n/a & \ok \\   
    … …  
    67679   & FW. Spl. (8,8)     & \no & \ok & \ok & \ok & \no & \ok & --  & n/a & n/a & \ok \\   
    686810  & FW. Spl (14,10)    & \no & \ok & \ok & \ok & \no & \ok &  -- & n/a & n/a & \ok \\   
    69 \hline                                                                           
     69\hline                                                                           
    707011  & FW. Pk S. (2,2)    & \no & \no & \no & \no & \no & \no & --  & n/a & n/a & \ok \\   
    717112  & FW. Pk S. (4,4)    & \ok & \no & \no & \no & \no & \no & --  & n/a & n/a & \ok \\   
    … …  
    747415  & FW. Pk S. (8,8)    & \no & \ok & \ok & \ok & \no & \ok & --  & n/a & n/a & \ok \\   
    757516  & FW Pk S (14,10)    & \no & \ok & \ok & \ok & \no & \ok & --  & n/a & n/a & \ok \\   
    76 \hline                                                                   
     76\hline                                                                   
    777717  & Slid. W. (2,2)     & \ok & \no & \no & \no & \ok & \no & \ok & \no & \no & \ok \\   
    787818  & Slid. W. (4,4)     & \ok & \ok & \ok & \no & \ok & \ok & \ok & \no & \no & \ok \\   
    … …  
    818121  & Slid. W. (8,8)     & \ok & \ok & \ok & \ok & \no & \ok & \ok & \ok & \ok &\best\\   
    828222  & Slid. W. (14,10)   & \no & \ok & \ok & \ok & \no & \no & \ok & \no & \ok &\best\\   
    83 \hline                                                                   
     83\hline                                                                   
    848423  & Spline Ampl.       & \no &\nt  & \ok & \no & \no & \no & \no &\ok  & \no & \ok \\
    8585    &                    &     &\test&     &     &     &     &     &     &     &     \\
    … …  
    110110%%% mode: latex
    111111%%% TeX-master: "MAGIC_signal_reco"
     112%%% TeX-master: "MAGIC_signal_reco"
    112113%%% End:

  • trunk/MagicSoft/TDAS-Extractor/Speed.tex

    r6655 r6745  
    1 \section{CPU Requirements}
     1\section{CPU Requirements \label{sec:speed}}
    22
    33We tested the speed of the extractors by running them on an Intel\ Pentium\ IV,
    … …  
    6868\end{table}
    6969
     70
     71%%% Local Variables:
     72%%% mode: latex
     73%%% TeX-master: "MAGIC_signal_reco"
     74%%% End:
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