Changeset 6527 for trunk/MagicSoft


Ignore:
Timestamp:
02/16/05 15:45:18 (20 years ago)
Author:
gaug
Message:
*** empty log message ***
Location:
trunk/MagicSoft
Files:
3 edited

Legend:

Unmodified
Added
Removed
  • trunk/MagicSoft/Mars/Changelog

    r6515 r6527  
    2727     - replaced ROOT version check for the compiler from 4.02.00 to
    2828       4.01.00
     29
     30   * mranforest/MRFEnergyEst.cc
     31     - include "TVector.h", otherwise this class does not compile
    2932
    3033 2005/02/16 Abelardo Moralejo
  • trunk/MagicSoft/Mars/mranforest/MRFEnergyEst.cc

    r6492 r6527  
    4949#include "TStyle.h"
    5050#include "TCanvas.h"
     51#include "TVector.h"
    5152
    5253ClassImp(MRFEnergyEst);
  • trunk/MagicSoft/TDAS-Extractor/Calibration.tex

    r6519 r6527  
    168168\begin{figure}[htp]
    169169\centering
    170 \includegraphics[height=0.95\textheight]{UnsuitVsExtractor-5LedsUV-Colour-13.eps}
     170\includegraphics[height=0.95\textheight]{UnsuitVsExtractor-5LedsUV-Colour-12.eps}
    171171\caption{Un-calibrated pixels and outlier events for a typical calibration 
    172172pulse of UV-light which does not saturate the high-gain readout.}
     
    204204\par
    205205In general, one can also find that all ``sliding window''-algorithms (extractors \#17-32) discard
    206 less pixels than the corresponding ``fixed window''-ones (extractors \#1--16). The digital filter with
    207 the correct weights (extractors \#30-33) discards the least number of pixels and is also robust against
    208 slight modifications of its weights (extractors \#28--30).
    209 \par
    210 Also the ``spline'' algorithms on small 
    211 windows (extractors \#23--25) discard less pixels than the previous extractors.
    212 \par
    213 It seems also that the spline algorithm extracting the amplitude of the signal produces an over-proportional
    214 number of excluded events in the low-gain. The same, however in a less significant manner, holds for
    215 the digital filter with high-low-gain inverted weights. The limit of stability with respect to
    216 changes  in the pulse form seems to be reached, there.
     206less pixels than the corresponding ``fixed window''-ones (extractors \#1--16).
     207
     208The spline (extractors \#23--27) and the digital filter with the correct weights (extractors \#30-33) discard
     209the least number of pixels and are also robust against slight modifications of the pulse form
     210(of the weights for the digital filter).
    217211\par
    218212Concerning the numbers of outliers, one can conclude that in general, the numbers are very low never exceeding
    2192130.1\% except for the amplitude-extracting spline which seems to mis-reconstruct a certain type of events.
     214It seems however that the spline algorithm extracting the amplitude of the signal produces an over-proportional
    220215\par
    221216In conclusion, already this first test excludes all extractors with too large window sizes because
    222217they are not able to extract cleanly small signals produced by about 4 photo-electrons. Moreover,
    223 some extractors do not reproduce the signals as expected in the low-gain.
    224 
    225 %The excluded extractors are:
    226 %\begin{itemize}
    227 %\item: MExtractFixedWindow Nr. 3--5
    228 %\item: MExtractFixedWindowSpline Nr. 6--11 (all)
    229 %\item: MExtractFixedWindowPeakSearch Nr. 14--16
    230 %\item: MExtractTimeAndChargeSlidingWindow Nr. 21--22
    231 %\item: MExtractTimeAndChargeSpline Nr. 23 and 27
    232 %\end{itemize}
     218the amplitude extracting spline produces a significantly higher number of outlier events.
    233219
    234220\clearpage
     
    240226Assuming that the readout chain adds only negligible noise to the one
    241227introduced by the photo-multiplier itself, one can make the assumption that the variance of the
    242 true signal $S$ is the amplified Poisson variance of the number of photo-electrons,
     228true signal, $S$, is the amplified Poisson variance of the number of photo-electrons,
    243229multiplied with the excess noise of the photo-multiplier which itself is
    244 characterized by the excess-noise factor $F$.
     230characterized by the excess-noise factor $F$:
    245231
    246232\begin{equation}
     
    250236
    251237After introducing the effect of the night-sky background (eq.~\ref{eq:rmssubtraction})
    252 in formula~\ref{eq:excessnoise} and assuming that the variance of the number of photo-electrons is equal
     238and assuming that the variance of the number of photo-electrons is equal
    253239to the mean number of photo-electrons (because of the Poisson distribution),
    254 one obtains an expression to retrieve the mean number of photo-electrons  impinging on the pixel from the
    255 mean extracted signal $<\widehat{S}>$,
    256 its variance $Var(\widehat{S})$ and the RMS of the extracted signal obtained from
     240one obtains an expression to retrieve the mean number of photo-electrons  impinging on the photo-multiplier from the
     241mean extracted signal, $\widehat{S}$, and the RMS of the extracted signal obtained from
    257242pure pedestal runs $R$ (see section~\ref{sec:ffactor}):
    258243
     
    276261\par
    277262Figures~\ref{fig:phe:5ledsuv},~\ref{fig:phe:1leduv},~\ref{fig:phe:2ledsgreen}~and~\ref{fig:phe:23ledsblue} show
    278 some of the obtained results. Although one can see a rather good stability for the standard
     263some of the obtained results. One can see a rather good stability for the standard
    279264{\textit{\bf 5\,Leds\,UV}}\ pulse, except for the extractors {\textit{\bf MExtractFixedWindowPeakSearch}}, initialized
    280 with an extraction window of 2 slices and  {\textit{\bf MExtractTimeAndChargeDigitalFilter}}, initialized with
    281 an extraction window of 4 slices (extractor \#29).
     265with an extraction window of 2 slices.
    282266\par
    283267There is a considerable difference for all shown non-standard pulses. Especially the pulses from green
     
    289273\par
    290274The strongest discrepancy is observed in the low-gain extraction (fig.~\ref{fig:phe:23ledsblue}) where all
    291 fixed window extractors with too small extraction windows fail to reconstruct the correct numbers.
     275fixed window extractors with extraction windows smaller than 8 FADC slices fail to reconstruct the correct numbers.
    292276This has to do with the fact that
    293 the fixed window extractors fail to do catch a significant part of the (larger) pulse because of the
    294 1~FADC slice event-to-event jitter.
     277the fixed window extractors fail to catch a significant part of the (larger) pulse because of the
     2781~FADC slice event-to-event jitter. Also the sliding windows smaller than 6 FADC slices and the spline smaller than
     2792 FADC slices reproduce too small numbers of photo-electrons. Moreover, the digital filter shows a small dependency
     280of the number of photo-electrons w.r.t. the extration window.
     281\par
    295282
    296283
     
    345332
    346333One can see that all extractors using a large window belong to the class of extractors being affected
    347 by the secondary pulses, except for the digital filter. The only exception to this rule is the digital filter
    348 which - despite of its 6 slices extraction window - seems to filter out all the secondary pulses.
    349 \par
    350 The extractor {\textit{\bf MExtractFixedWindowPeakSearch}} at low extraction windows apparently yields chronically low
    351 numbers of photo-electrons. This is due to the fact that the decision to fix the extraction window is
    352 made sometimes by an inner pixel and sometimes by an outer one since the camera is flat-fielded and the
    353 pixel carrying the largest non-saturated peak-search window is more or less found by a random signal
    354 fluctuation. However, inner and outer pixels have a systematic offset of about 0.5 to 1 FADC slices.
    355 Thus, the extraction fluctuates artificially for one given channel which results in a systematically
    356 large variance and thus in a systematically low reconstructed number of photo-electrons. This test thus
    357 excludes the extractors \#11--13.
    358 \par
    359 Moreover, one can see that the extractors applying a small fixed window do not get the ratio of
    360 photo-electrons correctly between outer to inner pixels for the green and blue pulses.
     334by the secondary pulses, except for the digital filter.
    361335\par
    362336The extractor {\textit{\bf MExtractTimeAndChargeDigitalFilter}} seems to be stable against modifications in the
    363337exact form of the weights in the high-gain readout channel since all applied weights yield about
    364 the same number of photo-electrons and the same ratio of outer vs. inner pixels. This statement does not
    365 hold any more for the low-gain, as can be seen in figure~\ref{fig:phe:23ledsblue}. There, the application
    366 of high-gain weights to the low-gain signal (extractors \#34--39) produces a too low number of photo-electrons
    367 and also a too low ratio of outer vs. inner pixels.
    368 \par
    369 All sliding window and spline algorithms yield a stable ratio of outer vs. inner pixels in the low-gain,
    370 however the effect of raising the number of photo-electrons with the extraction window is very pronounced.
    371 Note that in figure~\ref{fig:phe:23ledsblue}, the number of photo-electrons rises by about a factor 1.4,
    372 which is slightly higher than in the case of the high-gain channel (figure~\ref{fig:phe:2ledsgreen}).
    373 \par
    374 Concluding, there is no fixed window extractor yielding the correct number of photo-electrons
    375 for the low-gain, except for the largest extraction window of 8 and 10 low-gain slices.
     338the same number of photo-electrons and the same ratio of outer vs. inner pixels, except if one applies the cosmics
     339weights to the very low-intensity pulse $1\,LED\,UV$ where a slight increase in photo-electrons is observed.
     340\par
     341All sliding window and spline algorithms yield a stable ratio of outer vs. inner pixels in the high and the low-gain.
     342\par
     343Concluding, there is no fixed window extractor yielding always the correct number of photo-electrons,
     344except for the extraction window of 8 FADC slices.
    376345Either the number of photo-electrons itself is wrong or the ratio of outer vs. inner pixels is
    377346not correct. All sliding window algorithms seem to reproduce the correct numbers if one takes into
    378347account the after-pulse behaviour of the light pulser itself. The digital filter seems to be
    379 unstable against exchanging the pulse form to match the slimmer high-gain pulses, though.
    380 
    381 \par
    382 \ldots {\textit{\bf EXCLUDED : CW4, UV4 No stability High-gain vs. LoGain}}
    383 \par
     348stable against exchanging the pulse width from 1~to~4\,ns.
    384349
    385350%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Note: See TracChangeset for help on using the changeset viewer.