Changeset 6527
- Timestamp:
- 02/16/05 15:45:18 (20 years ago)
- Location:
- trunk/MagicSoft
- Files:
-
- 3 edited
Legend:
- Unmodified
- Added
- Removed
-
trunk/MagicSoft/Mars/Changelog
r6515 r6527 27 27 - replaced ROOT version check for the compiler from 4.02.00 to 28 28 4.01.00 29 30 * mranforest/MRFEnergyEst.cc 31 - include "TVector.h", otherwise this class does not compile 29 32 30 33 2005/02/16 Abelardo Moralejo -
trunk/MagicSoft/Mars/mranforest/MRFEnergyEst.cc
r6492 r6527 49 49 #include "TStyle.h" 50 50 #include "TCanvas.h" 51 #include "TVector.h" 51 52 52 53 ClassImp(MRFEnergyEst); -
trunk/MagicSoft/TDAS-Extractor/Calibration.tex
r6519 r6527 168 168 \begin{figure}[htp] 169 169 \centering 170 \includegraphics[height=0.95\textheight]{UnsuitVsExtractor-5LedsUV-Colour-1 3.eps}170 \includegraphics[height=0.95\textheight]{UnsuitVsExtractor-5LedsUV-Colour-12.eps} 171 171 \caption{Un-calibrated pixels and outlier events for a typical calibration 172 172 pulse of UV-light which does not saturate the high-gain readout.} … … 204 204 \par 205 205 In 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. 206 less pixels than the corresponding ``fixed window''-ones (extractors \#1--16). 207 208 The spline (extractors \#23--27) and the digital filter with the correct weights (extractors \#30-33) discard 209 the least number of pixels and are also robust against slight modifications of the pulse form 210 (of the weights for the digital filter). 217 211 \par 218 212 Concerning the numbers of outliers, one can conclude that in general, the numbers are very low never exceeding 219 213 0.1\% except for the amplitude-extracting spline which seems to mis-reconstruct a certain type of events. 214 It seems however that the spline algorithm extracting the amplitude of the signal produces an over-proportional 220 215 \par 221 216 In conclusion, already this first test excludes all extractors with too large window sizes because 222 217 they 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} 218 the amplitude extracting spline produces a significantly higher number of outlier events. 233 219 234 220 \clearpage … … 240 226 Assuming that the readout chain adds only negligible noise to the one 241 227 introduced 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,228 true signal, $S$, is the amplified Poisson variance of the number of photo-electrons, 243 229 multiplied with the excess noise of the photo-multiplier which itself is 244 characterized by the excess-noise factor $F$ .230 characterized by the excess-noise factor $F$: 245 231 246 232 \begin{equation} … … 250 236 251 237 After 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 equal238 and assuming that the variance of the number of photo-electrons is equal 253 239 to 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 240 one obtains an expression to retrieve the mean number of photo-electrons impinging on the photo-multiplier from the 241 mean extracted signal, $\widehat{S}$, and the RMS of the extracted signal obtained from 257 242 pure pedestal runs $R$ (see section~\ref{sec:ffactor}): 258 243 … … 276 261 \par 277 262 Figures~\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 standard263 some of the obtained results. One can see a rather good stability for the standard 279 264 {\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). 265 with an extraction window of 2 slices. 282 266 \par 283 267 There is a considerable difference for all shown non-standard pulses. Especially the pulses from green … … 289 273 \par 290 274 The 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.275 fixed window extractors with extraction windows smaller than 8 FADC slices fail to reconstruct the correct numbers. 292 276 This 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. 277 the fixed window extractors fail to catch a significant part of the (larger) pulse because of the 278 1~FADC slice event-to-event jitter. Also the sliding windows smaller than 6 FADC slices and the spline smaller than 279 2 FADC slices reproduce too small numbers of photo-electrons. Moreover, the digital filter shows a small dependency 280 of the number of photo-electrons w.r.t. the extration window. 281 \par 295 282 296 283 … … 345 332 346 333 One 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. 334 by the secondary pulses, except for the digital filter. 361 335 \par 362 336 The extractor {\textit{\bf MExtractTimeAndChargeDigitalFilter}} seems to be stable against modifications in the 363 337 exact 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. 338 the same number of photo-electrons and the same ratio of outer vs. inner pixels, except if one applies the cosmics 339 weights to the very low-intensity pulse $1\,LED\,UV$ where a slight increase in photo-electrons is observed. 340 \par 341 All sliding window and spline algorithms yield a stable ratio of outer vs. inner pixels in the high and the low-gain. 342 \par 343 Concluding, there is no fixed window extractor yielding always the correct number of photo-electrons, 344 except for the extraction window of 8 FADC slices. 376 345 Either the number of photo-electrons itself is wrong or the ratio of outer vs. inner pixels is 377 346 not correct. All sliding window algorithms seem to reproduce the correct numbers if one takes into 378 347 account 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 348 stable against exchanging the pulse width from 1~to~4\,ns. 384 349 385 350 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Note:
See TracChangeset
for help on using the changeset viewer.