--- /dev/null
+/*******************************************************************************
+ * Copyright(c) 2003, IceCube Experiment at the South Pole. All rights reserved.
+ *
+ * Author: The IceCube RALICE-based Offline Project.
+ * Contributors are mentioned in the code where appropriate.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation strictly for non-commercial purposes is hereby granted
+ * without fee, provided that the above copyright notice appears in all
+ * copies and that both the copyright notice and this permission notice
+ * appear in the supporting documentation.
+ * The authors make no claims about the suitability of this software for
+ * any purpose. It is provided "as is" without express or implied warranty.
+ *******************************************************************************/
+
+// $Id$
+
+///////////////////////////////////////////////////////////////////////////
+// Class IceXtalk
+// TTask derived class to perform cross talk hit correction.
+//
+// This task takes the current event in memory and uses the attached
+// OM database to identify pairs of OMs which might induce cross talk.
+// For each particular transmitter and receiver pair within the event
+// a probability for cross talk induction is determined on basis of
+// the hit data and the cross talk probability functions from the OM database.
+// If this probability is above a certain threshold "pmin" and the difference
+// in LE between transmitter and receiver signal is within the bounds as
+// given by the Xtalk calibration data, the occurrence of a cross talk signal
+// of "pe" photo-electrons in the receiver is assumed and this signal is
+// lateron subtracted from the receiver ADC signal.
+// The subtraction of the Xtalk signal from the various hits is delayed
+// until the very end, since receiver OMs may also act as transmitter OMs
+// for other pair combinations.
+// In case a transmitter OM was flagged as a bad module, the check on the
+// LE time difference will not be performed and a cross talk induction
+// decision will be solely based on the corresponding probability, since
+// the latter only depends on the un-calibrated signal amplitude of the
+// transmitter hit.
+// So, hits which have induced cross talk are not completely removed
+// but their signal is corrected for the cross talk.
+// This will prevent severe losses when studying UHE events, where cross
+// talk effects are expected to have negligible effects on the observed
+// large module signals.
+//
+// The values of "pmin" and "pe" can be set by the user via the
+// SetMinProb() and SetXtalkPE() memberfunctions.
+// The default values are pmin=0.5 and pe=1.
+//
+// In case this processor is followed by an ADC threshold hit cleaning
+// procedure, hits which only contained cross talk can be efficiently
+// skipped or removed from the event.
+// In case one would like to always remove a hit which containes induced
+// cross talk, one could set the "pe" parameter to some very large value.
+// This will result in cross talk induced hits to get large negative ADC
+// signals and can as such easily be skipped/removed afterwards.
+//
+// Note : This processor only works properly on Time and ADC calibrated data.
+//
+//--- Author: Nick van Eijndhoven 11-aug-2005 Utrecht University
+//- Modified: NvE $Date$ Utrecht University
+///////////////////////////////////////////////////////////////////////////
+
+#include "IceXtalk.h"
+#include "Riostream.h"
+
+ClassImp(IceXtalk) // Class implementation to enable ROOT I/O
+
+IceXtalk::IceXtalk(const char* name,const char* title) : TTask(name,title)
+{
+// Default constructor.
+ fCalfile=0;
+ fOmdb=0;
+ fPmin=0.5;
+ fPe=1;
+}
+///////////////////////////////////////////////////////////////////////////
+IceXtalk::~IceXtalk()
+{
+// Default destructor.
+ if (fCalfile)
+ {
+ delete fCalfile;
+ fCalfile=0;
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+void IceXtalk::SetOMdbase(AliObjMatrix* omdb)
+{
+// Set the pointer to the OM database.
+// Note : this will overrule a previously attached database.
+ fOmdb=omdb;
+}
+///////////////////////////////////////////////////////////////////////////
+void IceXtalk::SetCalibFile(TString name)
+{
+// Set the calibration ROOT file as created with IceCal2Root.
+// Note : this will overrule a previously attached database.
+ fCalfile=new TFile(name.Data());
+ if (fCalfile)
+ {
+ AliObjMatrix* fOmdb=(AliObjMatrix*)fCalfile->Get("Cal-OMDBASE");
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+void IceXtalk::SetMinProb(Float_t pmin)
+{
+// Set the minimal probability for cross talk induction.
+ fPmin=pmin;
+}
+///////////////////////////////////////////////////////////////////////////
+void IceXtalk::SetXtalkPE(Float_t pe)
+{
+// Set the nominal Xtalk signal in photo-electron equivalent.
+ fPe=pe;
+}
+///////////////////////////////////////////////////////////////////////////
+void IceXtalk::Exec(Option_t* opt)
+{
+// Implementation of cross talk hit correction.
+
+ TString name=opt;
+ AliJob* parent=(AliJob*)(gROOT->GetListOfTasks()->FindObject(name.Data()));
+
+ if (!parent) return;
+
+ IceEvent* evt=(IceEvent*)parent->GetObject("IceEvent");
+ if (!evt) return;
+
+ TObjArray xhits; // Array with pointers to Xtalk hits to be corrected
+
+ IceAOM* omt=0; // Transmitter OM
+ IceAOM* omr=0; // Receiver OM
+ TF1* fxtalk=0; // The Xtalk probability function
+ Int_t idtrans=0;
+ Int_t idrec=0;
+ Float_t adct=0,let=0;
+ Float_t p=0;
+ Float_t adcr=0,ler=0;
+ Int_t ibad=0;
+ Float_t cpar=0,bpar=0,dlemin=0,dlemax=0,test=0;
+ Float_t dle=0;
+ Float_t sigcor=0;
+ Int_t ndev=evt->GetNdevices();
+ for (Int_t idev=1; idev<=ndev; idev++)
+ {
+ omt=(IceAOM*)evt->GetDevice(idev);
+ if (!omt) continue;
+ idtrans=omt->GetUniqueID();
+
+ // Also take bad transmitter modules into account
+ ibad=omt->GetDeadValue("ADC");
+ if (ibad) omt->SetAlive("ADC");
+
+ // Check for corresponding receiver modules
+ for (Int_t jdev=1; jdev<=ndev; jdev++)
+ {
+ // No Xtalk from a module to itself
+ if (jdev==idev) continue;
+
+ omr=(IceAOM*)evt->GetDevice(jdev);
+ if (!omr) continue;
+ idrec=omr->GetUniqueID();
+
+ fxtalk=(TF1*)fOmdb->GetObject(idtrans,idrec+1);
+ if (!fxtalk) continue;
+
+ // Determine Xtalk probability for each transmitter hit
+ for (Int_t ithit=1; ithit<=omt->GetNhits(); ithit++)
+ {
+ AliSignal* st=omt->GetHit(ithit);
+ if (!st) continue;
+
+ adct=st->GetSignal("ADC",-4); // Get uncalibrated amplitude
+ dlemin=fxtalk->GetParameter("dLE-min");
+ dlemax=fxtalk->GetParameter("dLE-max");
+ // Protection against overflow in Xtalk prob. function
+ cpar=fxtalk->GetParameter("C");
+ bpar=fxtalk->GetParameter("B");
+ test=(adct-cpar)/bpar;
+ if (test>100)
+ {
+ p=1;
+ }
+ else if (test<-100)
+ {
+ p=0;
+ }
+ else
+ {
+ p=fxtalk->Eval(adct);
+ }
+ if (p<fPmin) continue;
+
+ // Xtalk flagging for each receiver hit
+ for (Int_t irhit=1; irhit<=omr->GetNhits(); irhit++)
+ {
+ AliSignal* sr=omr->GetHit(irhit);
+ if (!sr) continue;
+
+ // Check calibrated LE time differences
+ if (!ibad)
+ {
+ let=st->GetSignal("LE",4);
+ ler=sr->GetSignal("LE",4);
+ dle=ler-let;
+ if (dle<dlemin || dle>dlemax) continue;
+ }
+ // Register this receiver hit to be corrected
+ xhits.Add(sr);
+ }
+ } // end of transmitter hit loop
+ } // end of receiver OM loop
+
+ // Restore the original transmitter dead flag value
+ if (ibad) omt->SetDead("ADC");
+ } // end of transmitter OM loop
+
+ // Perform the Xtalk signal correction to the registered receiver hits
+ for (Int_t ix=0; ix<xhits.GetEntries(); ix++)
+ {
+ AliSignal* sx=(AliSignal*)xhits.At(ix);
+ if (!sx) continue;
+ adcr=sx->GetSignal("ADC");
+ sigcor=fPe;
+ // If stored ADC data is un-calibrated, convert fPe to raw ADC value
+ AliSignal* parent=(AliSignal*)sx->GetDevice();
+ if (parent)
+ {
+ if (parent->GetCalFunction("ADC"));
+ {
+ idrec=parent->GetUniqueID();
+ omr=(IceAOM*)fOmdb->GetObject(idrec,1);
+ TF1* fdecal=0;
+ if (omr) fdecal=omr->GetDecalFunction("ADC");
+ if (fdecal) sigcor=fdecal->Eval(fPe);
+ }
+ }
+ adcr=adcr-sigcor;
+ sx->SetSignal(adcr,"ADC");
+ }
+}
+///////////////////////////////////////////////////////////////////////////
git://git.uio.no / u / mrichter / AliRoot.git / commitdiff