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trunk/MagicSoft/TDAS-Extractor/Algorithms.tex (modified) (13 diffs)
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trunk/MagicSoft/TDAS-Extractor/Algorithms.tex
r6645 r6647 6 6 There, the base classes {\textit{\bf MExtractor}}, {\textit{\bf MExtractTime}}, {\textit{\bf MExtractTimeAndCharge}} and 7 7 all individual extractors can be found. Figure~\ref{fig:extractorclasses} gives a sketch of the 8 inheritances of each class and what each class calculates.8 inheritances and tasks of each class. 9 9 10 10 \begin{figure}[htp] … … 17 17 The following base classes for the extractor tasks are used: 18 18 \begin{description} 19 \item[MExtractor:\xspace] This class provides the basic data members equal for all extractorswhich are:19 \item[MExtractor:\xspace] This class provides the basic data members, equal for all extractors, which are: 20 20 \begin{enumerate} 21 \item Global extraction ranges, parameterized by the variables21 \item Global extraction ranges, defined by the variables 22 22 {\textit{\bf fHiGainFirst, fHiGainLast, fLoGainFirst, fLoGainLast}} and the function {\textit{\bf SetRange()}}. 23 23 The ranges always {\textit{\bf include}} the edge slices. 24 24 \item An internal variable {\textit{\bf fHiLoLast}} regulating the overlap of the desired high-gain 25 25 extraction range into the low-gain array. 26 \item The maximum possible FADC value, before the slice is declared as saturated, parameterized26 \item The maximum possible FADC value, before the slice is declared as saturated, defined 27 27 by the variable {\textit{\bf fSaturationLimit}} (default:\,254). 28 28 \item The typical delay between high-gain and low-gain slices, expressed in FADC slices and parameterized 29 29 by the variable {\textit{\bf fOffsetLoGain}} (default:\,1.51) 30 \item Pointers to the usedstorage containers {\textit{\bf MRawEvtData, MRawRunHeader, MPedestalCam}}31 and~{\textit{\bf MExtractedSignalCam}}, parameterized by the variables30 \item Pointers to the storage containers {\textit{\bf MRawEvtData, MRawRunHeader, MPedestalCam}} 31 and~{\textit{\bf MExtractedSignalCam}}, defined by the variables 32 32 {\textit{\bf fRawEvt, fRunHeader, fPedestals}} and~{\textit{\bf fSignals}}. 33 \item Names of the usedstorage containers to be searched for in the parameter list, parameterized33 \item Names of the storage containers to be searched for in the parameter list, parameterized 34 34 by the variables {\textit{\bf fNamePedestalCam}} and~{\textit{\bf fNameSignalCam}} (default: ``MPedestalCam'' 35 35 and~''MExtractedSignalCam''). … … 56 56 57 57 \item[MExtractTime:\xspace] This class provides - additionally to those already declared in {\textit{\bf MExtractor}} - 58 the basic data members equal for all time extractorswhich are:58 the basic data members, equal for all time extractors, which are: 59 59 \begin{enumerate} 60 \item Pointer to the usedstorage container {\textit{\bf MArrivalTimeCam}}61 parameterized by the variable s60 \item Pointer to the storage container {\textit{\bf MArrivalTimeCam}} 61 parameterized by the variable 62 62 {\textit{\bf fArrTime}}. 63 \item The name of the used``MArrivalTimeCam''-container to be searched for in the parameter list,63 \item The name of the ``MArrivalTimeCam''-container to be searched for in the parameter list, 64 64 parameterized by the variables {\textit{\bf fNameTimeCam}} (default: ``MArrivalTimeCam'' ). 65 65 \end{enumerate} … … 82 82 \item[MExtractTimeAndCharge:\xspace] This class provides - additionally to those already declared in 83 83 {\textit{\bf MExtractor}} and {\textit{\bf MExtractTime}} - 84 the basic data members equal for all time and charge extractorswhich are:84 the basic data members, equal for all time and charge extractors, which are: 85 85 \begin{enumerate} 86 86 \item The actual extraction window sizes, parameterized by the variables … … 118 118 119 119 The pure signal extractors have in common that they reconstruct only the 120 charge, but not the arrival time. All treated extractorshere derive from the MARS-base120 charge, but not the arrival time. All extractors treated here derive from the MARS-base 121 121 class {\textit{\bf MExtractor}} which provides the following facilities: 122 122 … … 133 133 134 134 As the pulses jitter by about one FADC slice, 135 not every pulse lies exactly within the optimal limits, especially if one takes small135 not every pulse lies exactly within the optimal limits, especially if one chooses small 136 136 extraction windows. 137 137 Moreover, the readout position with respect to the trigger position has changed a couple … … 144 144 It simply adds the FADC slice contents in the assigned ranges. 145 145 As it does not correct for the clock-noise, only an even number of samples is allowed. 146 Figure~\ref{fig:fixedwindowsketch} gives a sketch of the used extraction ranges forthis147 paper and two typical calibration pulses.146 Figure~\ref{fig:fixedwindowsketch} gives a sketch of the extraction ranges used in this 147 paper and for two typical calibration pulses. 148 148 149 149 \begin{figure}[htp] … … 164 164 spline interpolated FADC slice values from a fixed extraction range. The edge slices are counted as half. 165 165 As it does not correct for the clock-noise, only an odd number of samples is allowed. 166 Figure~\ref{fig:fixedwindowsplinesketch} gives a sketch of the used extraction ranges forthis167 paper and twotypical calibration pulses.166 Figure~\ref{fig:fixedwindowsplinesketch} gives a sketch of the extraction ranges used in this 167 paper and for typical calibration pulses. 168 168 169 169 \begin{figure}[htp] … … 182 182 The basic idea of this extractor is to correct for coherent movements in arrival time for all pixels, 183 183 as e.g. caused by the trigger jitter. 184 In a first loop , it fixes a reference point defined asthe highest sum of184 In a first loop over the pixels, it determined a reference point slices number defined by the highest sum of 185 185 consecutive non-saturating FADC slices in a (smaller) peak-search window. 186 186 \par 187 187 In a second loop over the pixels, 188 it adds the FADC contents starting from a pre-defined offset from the obtained peak-search window 189 over an extraction window of a pre-defined window size. 188 it adds the contents of the FADC slices starting from the reference point over an extraction window of a pre-defined window size. 190 189 It loops twice over all pixels in every event, because it has to find the reference point, first. 191 As it does not correct for the clock-noise, only an even number of samples isallowed.190 As it does not correct for the clock-noise, only extraction windows with an even number of samples are allowed. 192 191 For a high intensity calibration run causing high-gain saturation in the whole camera, this 193 192 extractor apparently fails since only dead pixels are taken into account in the peak search … … 221 220 \subsection{Combined Extractors} 222 221 223 The combined extractors have in common that they reconstruct the arrival time and 224 the charge at the same time and for the same pulse. 225 All treated combined extractors here derive from the MARS-base 222 The combined extractors have in common that for a given pulse, they reconstruct 223 both the arrival time and 224 the charge. 225 All combined extractors described here derive from the MARS-base 226 226 class {\textit{\bf MExtractTimeAndCharge}} which itself derives from MExtractor and MExtractTime. 227 227 It provides the following facilities: … … 230 230 \item Only one loop over all pixels is performed. 231 231 \item The individual FADC slice values get the clock-noise-corrected pedestals immediately subtracted. 232 \item The low-gain extraction range is adapted dynamically, based on the computed arrival time 233 from the high-gain samples. 234 \item Extracted times from the low-gain samples get corrected for the intrinsic time delay of the low-gain 232 \item The low-gain extraction range is adapted dynamically, based on the arrival time computed from the high-gain samples. 233 \item Arrival times extracted from the low-gain samples get corrected for the intrinsic time delay of the low-gain 235 234 pulse. 236 235 \item The global extraction limits can be set from outside. … … 265 264 266 265 \begin{equation} 267 t = \frac{\sum_{i=i_0}^{i_0+ ws} s_i \cdot i}{\sum_{i=i_0}^{i_0+ws} i}268 \end{equation} 269 where $i$ denotes the FADC slice index, starting from $i_0$270 window and running over a window of size $ws$. $s_i$ the clock-noise and266 t = \frac{\sum_{i=i_0}^{i_0+\mathrm{\it ws}-1} s_i \cdot i}{\sum_{i=i_0}^{i_0+\mathrm{\it ws}-1} i} 267 \end{equation} 268 where $i$ denotes the FADC slice index, starting from slice $i_0$ 269 and running over a window of size $\mathrm{\it ws}$. $s_i$ the clock-noise and 271 270 pedestal-corrected FADC slice contents at slice position $i$. 272 271 \par … … 296 295 \begin{description} 297 296 \item[Extraction Type Amplitude:\xspace] The amplitude of the spline maximum is taken as charge signal 298 and the (precise) position of the maximum is returned as arrival time. This type is faster, since it 299 performs not spline integration. 297 and the (precise) position of the maximum is returned as arrival time. This type is faster, since a spline integration is not performed. 300 298 \item[Extraction Type Integral:\xspace] The integrated spline between maximum position minus 301 299 rise time (default: 1.5 slices) and maximum position plus fall time (default: 4.5 slices)
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