- Timestamp:
- 12/20/04 22:33:59 (20 years ago)
- Location:
- trunk/MagicSoft/TDAS-Extractor
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- 2 edited
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trunk/MagicSoft/TDAS-Extractor/Changelog
r5612 r5647 19 19 20 20 -*-*- END OF LINE -*-*- 21 22 2004/12/16: Markus Gaug 23 * Performance.tex: included sections dealing with calibration (not yet 24 ready) 25 26 21 27 22 28 2004/12/16: Hendrik Bartko -
trunk/MagicSoft/TDAS-Extractor/Performance.tex
r5645 r5647 370 370 \subsubsection{Time resolution} 371 371 372 The extractors \#17--32 are able to extract also the arrival time of each pulse. In the calibration, 373 we have a fast-rising pulse, uniform over camera also in time. We estimate the time-uniformity to better 374 than 300\,ps, a limit due to the different travel times of the light between inner and outer parts of the 375 camera. Since the calibraion does not have an absolute measurement of the arrival time, we measure 376 the relative arrival time, i.e. 377 378 \begin{equation} 379 \delta t_i = t_i - t_1 380 \end{equation} 381 382 where $t_i$ denotes the reconstructed arrival time of pixel number $i$ and $t_1$ the reconstructed 383 arrival time of pixel number 1 (software numbering). For one calibration run, one can then fill 384 histograms of $\delta t_i$ for each pixel which yields then a mean $<\delta t_i>$, comparable to 385 systematic offsets in the signal delay and a sigma $\sigma(\delta t_i)$ which is a measure of the 386 combined time resolutions of pixel $i$ and pixel 1. Assuming that the PMTs and readout channels are 387 of a same kind, we obtain an approximate absolute time resolution of pixel $i$ by: 388 389 \begin{equation} 390 tres_i \approx \sigma(\delta t_i)/sqrt(2) 391 \end{equation} 392 393 Figures~\ref{fig:reltimesinner10leduv} and~\ref{fig:reltimesouter10leduv} show distributions of $<\delta t_i>$ 394 for 395 one typical inner pixel and one typical outer pixel and a non-saturating calibration pulse of UV-light, 396 obtained with three different extractors. One can see that the first two yield a Gaussian distribution 397 to a good approximation, whereas the third extractor shows a three-peak structure and cannot be fitted. 398 We discarded that particular extractor for this reason. 399 372 400 \begin{figure}[htp] 373 401 \centering … … 380 408 right plot the result of the sliding window with a window size of 2 FADC slices (extractor \#17). A 381 409 medium sized UV-pulse (10Leds UV) has been used which does not saturate the high-gain readout channel.} 382 \label{fig:reltimesinner }410 \label{fig:reltimesinner10leduv} 383 411 \end{figure} 384 412 … … 393 421 right plot the result of the sliding window with a window size of 2 FADC slices (extractor \#17). A 394 422 medium sized UV-pulse (10Leds UV) has been used which does not saturate the high-gain readout channel.} 395 \label{fig:reltimesouter} 396 \end{figure} 397 398 \begin{figure}[htp] 399 \centering 400 \includegraphics[width=0.45\linewidth]{RelArrTime_Pixel97_10LedBlue_Extractor32.eps} 401 \includegraphics[width=0.45\linewidth]{RelArrTime_Pixel97_10LedBlue_Extractor23.eps} 423 \label{fig:reltimesouter10leduv} 424 \end{figure} 425 426 Figures~\ref{fig:reltimesinner10ledsblue} and~\ref{fig:reltimesouter10ledsblue} show distributions of 427 $<\delta t_i>$ for 428 one typical inner and one typical outer pixel and a high-gain-saturating calibration pulse of blue-light, 429 obtained with two different extractors. One can see that the first (extractor \#23) yields a Gaussian 430 distribution to a good approximation, whereas the second (extractor \#32) shows a two-peak structure 431 and cannot be fitted. 432 \par 433 \ldots {\it Unfortunately, this happens for all digital filter extractors in the low-gain. 434 The reason is not yet understood, and has to be found by Hendrik... } \ldots 435 \par 436 437 \begin{figure}[htp] 438 \centering 439 \includegraphics[width=0.31\linewidth]{RelArrTime_Pixel97_10LedBlue_Extractor23.eps} 440 \includegraphics[width=0.31\linewidth]{RelArrTime_Pixel97_10LedBlue_Extractor32.eps} 402 441 \caption{Example of a two distributions of relative arrival times of an inner pixel with respect to 403 the arrival time of the reference pixel Nr. 1. The left plot shows the result using the digital filter404 (extractor \#32), the right plot shows the result obtained with the half-maximum of the spline. A442 the arrival time of the reference pixel Nr. 1. The left plot shows the result using the half-maximum of the spline (extractor \#23), the right plot shows the result obtained with the digital filter 443 (extractor \#32). A 405 444 medium sized Blue-pulse (10Leds Blue) has been used which saturates the high-gain readout channel.} 406 \label{fig:reltimesinner} 407 \end{figure} 408 409 \begin{figure}[htp] 410 \centering 411 \includegraphics[width=0.45\linewidth]{RelArrTime_Pixel400_10LedBlue_Extractor32.eps} 412 \includegraphics[width=0.45\linewidth]{RelArrTime_Pixel400_10LedBlue_Extractor23.eps} 445 \label{fig:reltimesinner10ledsblue} 446 \end{figure} 447 448 449 450 \begin{figure}[htp] 451 \centering 452 \includegraphics[width=0.31\linewidth]{RelArrTime_Pixel400_10LedBlue_Extractor23.eps} 453 \includegraphics[width=0.31\linewidth]{RelArrTime_Pixel400_10LedBlue_Extractor32.eps} 413 454 \caption{Example of a two distributions of relative arrival times of an outer pixel with respect to 414 the arrival time of the reference pixel Nr. 1. The left plot shows the result using the digital filter415 (extractor \#32), the right plot shows the result obtained with the half-maximum of the spline. A455 the arrival time of the reference pixel Nr. 1. The left plot shows the result using the half-maximum of the spline (extractor \#23), the right plot shows the result obtained with the digital filter 456 (extractor \#32). A 416 457 medium sized Blue-pulse (10Leds Blue) has been used which saturates the high-gain readout channel.} 417 \label{fig:reltimesouter} 418 \end{figure} 419 420 458 \label{fig:reltimesouter10ledsblue} 459 \end{figure} 460 461 \begin{figure}[htp] 462 \centering 463 \includegraphics[width=0.95\linewidth]{TimeResExtractor-5LedsUV-Colour-12.eps} 464 \caption{Reconstructed arrival time resolutions from a typical, not saturating calibration pulse 465 of colour UV, reconstructed with each of the tested arrival time extractors. 466 The first plots shows the time resolutions obtained for the inner pixels, the second one 467 for the outer pixels. Points 468 denote the mean of all not-excluded pixels, the error bars their RMS.} 469 \label{fig:time:5ledsuv} 470 \end{figure} 471 472 \begin{figure}[htp] 473 \centering 474 \includegraphics[width=0.95\linewidth]{TimeResExtractor-1LedUV-Colour-04.eps} 475 \caption{Reconstructed arrival time resolutions from the lowest intensity calibration pulse 476 of colour UV (carrying a mean number of 4 photo-electrons), 477 reconstructed with each of the tested arrival time extractors. 478 The first plots shows the time resolutions obtained for the inner pixels, the second one 479 for the outer pixels. Points 480 denote the mean of all not-excluded pixels, the error bars their RMS.} 481 \label{fig:time:1leduv} 482 \end{figure} 483 484 \begin{figure}[htp] 485 \centering 486 \includegraphics[width=0.95\linewidth]{TimeResExtractor-2LedsGreen-Colour-02.eps} 487 \caption{Reconstructed arrival time resolutions from a typical, not saturating calibration pulse 488 of colour Green, reconstructed with each of the tested arrival time extractors. 489 The first plots shows the time resolutions obtained for the inner pixels, the second one 490 for the outer pixels. Points 491 denote the mean of all not-excluded pixels, the error bars their RMS.} 492 \label{fig:time:2ledsgreen} 493 \end{figure} 494 495 \begin{figure}[htp] 496 \centering 497 \includegraphics[width=0.95\linewidth]{TimeResExtractor-23LedsBlue-Colour-00.eps} 498 \caption{Reconstructed arrival time resolutions from the highest intensity calibration pulse 499 of colour blue, reconstructed with each of the tested arrival time extractors. 500 The first plots shows the time resolutions obtained for the inner pixels, the second one 501 for the outer pixels. Points 502 denote the mean of all not-excluded pixels, the error bars their RMS.} 503 \label{fig:time:23ledsblue} 504 \end{figure} 421 505 422 506 \clearpage
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