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deeffe5c | 1 | /******************************************************************************* |
2 | * Copyright(c) 2003, IceCube Experiment at the South Pole. All rights reserved. | |
3 | * | |
4 | * Author: The IceCube RALICE-based Offline Project. | |
5 | * Contributors are mentioned in the code where appropriate. | |
6 | * | |
7 | * Permission to use, copy, modify and distribute this software and its | |
8 | * documentation strictly for non-commercial purposes is hereby granted | |
9 | * without fee, provided that the above copyright notice appears in all | |
10 | * copies and that both the copyright notice and this permission notice | |
11 | * appear in the supporting documentation. | |
12 | * The authors make no claims about the suitability of this software for | |
13 | * any purpose. It is provided "as is" without express or implied warranty. | |
14 | *******************************************************************************/ | |
15 | ||
16 | // $Id$ | |
17 | ||
18 | /////////////////////////////////////////////////////////////////////////// | |
19 | // Class IceXtalk | |
20 | // TTask derived class to perform cross talk hit correction. | |
21 | // | |
22 | // This task takes the current event in memory and uses the attached | |
23 | // OM database to identify pairs of OMs which might induce cross talk. | |
24 | // For each particular transmitter and receiver pair within the event | |
25 | // a probability for cross talk induction is determined on basis of | |
26 | // the hit data and the cross talk probability functions from the OM database. | |
27 | // If this probability is above a certain threshold "pmin" and the difference | |
28 | // in LE between transmitter and receiver signal is within the bounds as | |
29 | // given by the Xtalk calibration data, the occurrence of a cross talk signal | |
30 | // of "pe" photo-electrons in the receiver is assumed and this signal is | |
31 | // lateron subtracted from the receiver ADC signal. | |
32 | // The subtraction of the Xtalk signal from the various hits is delayed | |
33 | // until the very end, since receiver OMs may also act as transmitter OMs | |
34 | // for other pair combinations. | |
35 | // In case a transmitter OM was flagged as a bad module, the check on the | |
36 | // LE time difference will not be performed and a cross talk induction | |
37 | // decision will be solely based on the corresponding probability, since | |
38 | // the latter only depends on the un-calibrated signal amplitude of the | |
39 | // transmitter hit. | |
40 | // So, hits which have induced cross talk are not completely removed | |
41 | // but their signal is corrected for the cross talk. | |
42 | // This will prevent severe losses when studying UHE events, where cross | |
43 | // talk effects are expected to have negligible effects on the observed | |
44 | // large module signals. | |
45 | // | |
46 | // The values of "pmin" and "pe" can be set by the user via the | |
47 | // SetMinProb() and SetXtalkPE() memberfunctions. | |
48 | // The default values are pmin=0.5 and pe=1. | |
49 | // | |
50 | // In case this processor is followed by an ADC threshold hit cleaning | |
51 | // procedure, hits which only contained cross talk can be efficiently | |
52 | // skipped or removed from the event. | |
53 | // In case one would like to always remove a hit which containes induced | |
54 | // cross talk, one could set the "pe" parameter to some very large value. | |
55 | // This will result in cross talk induced hits to get large negative ADC | |
56 | // signals and can as such easily be skipped/removed afterwards. | |
57 | // | |
58 | // Note : This processor only works properly on Time and ADC calibrated data. | |
59 | // | |
60 | //--- Author: Nick van Eijndhoven 11-aug-2005 Utrecht University | |
61 | //- Modified: NvE $Date$ Utrecht University | |
62 | /////////////////////////////////////////////////////////////////////////// | |
63 | ||
64 | #include "IceXtalk.h" | |
65 | #include "Riostream.h" | |
66 | ||
67 | ClassImp(IceXtalk) // Class implementation to enable ROOT I/O | |
68 | ||
69 | IceXtalk::IceXtalk(const char* name,const char* title) : TTask(name,title) | |
70 | { | |
71 | // Default constructor. | |
72 | fCalfile=0; | |
73 | fOmdb=0; | |
74 | fPmin=0.5; | |
75 | fPe=1; | |
76 | } | |
77 | /////////////////////////////////////////////////////////////////////////// | |
78 | IceXtalk::~IceXtalk() | |
79 | { | |
80 | // Default destructor. | |
81 | if (fCalfile) | |
82 | { | |
83 | delete fCalfile; | |
84 | fCalfile=0; | |
85 | } | |
86 | } | |
87 | /////////////////////////////////////////////////////////////////////////// | |
88 | void IceXtalk::SetOMdbase(AliObjMatrix* omdb) | |
89 | { | |
90 | // Set the pointer to the OM database. | |
91 | // Note : this will overrule a previously attached database. | |
92 | fOmdb=omdb; | |
93 | } | |
94 | /////////////////////////////////////////////////////////////////////////// | |
95 | void IceXtalk::SetCalibFile(TString name) | |
96 | { | |
97 | // Set the calibration ROOT file as created with IceCal2Root. | |
98 | // Note : this will overrule a previously attached database. | |
99 | fCalfile=new TFile(name.Data()); | |
100 | if (fCalfile) | |
101 | { | |
27e6d856 | 102 | fOmdb=(AliObjMatrix*)fCalfile->Get("Cal-OMDBASE"); |
deeffe5c | 103 | } |
104 | } | |
105 | /////////////////////////////////////////////////////////////////////////// | |
106 | void IceXtalk::SetMinProb(Float_t pmin) | |
107 | { | |
108 | // Set the minimal probability for cross talk induction. | |
109 | fPmin=pmin; | |
110 | } | |
111 | /////////////////////////////////////////////////////////////////////////// | |
112 | void IceXtalk::SetXtalkPE(Float_t pe) | |
113 | { | |
114 | // Set the nominal Xtalk signal in photo-electron equivalent. | |
115 | fPe=pe; | |
116 | } | |
117 | /////////////////////////////////////////////////////////////////////////// | |
118 | void IceXtalk::Exec(Option_t* opt) | |
119 | { | |
120 | // Implementation of cross talk hit correction. | |
121 | ||
122 | TString name=opt; | |
123 | AliJob* parent=(AliJob*)(gROOT->GetListOfTasks()->FindObject(name.Data())); | |
124 | ||
125 | if (!parent) return; | |
126 | ||
127 | IceEvent* evt=(IceEvent*)parent->GetObject("IceEvent"); | |
128 | if (!evt) return; | |
129 | ||
130 | TObjArray xhits; // Array with pointers to Xtalk hits to be corrected | |
131 | ||
132 | IceAOM* omt=0; // Transmitter OM | |
133 | IceAOM* omr=0; // Receiver OM | |
134 | TF1* fxtalk=0; // The Xtalk probability function | |
135 | Int_t idtrans=0; | |
136 | Int_t idrec=0; | |
137 | Float_t adct=0,let=0; | |
138 | Float_t p=0; | |
139 | Float_t adcr=0,ler=0; | |
140 | Int_t ibad=0; | |
141 | Float_t cpar=0,bpar=0,dlemin=0,dlemax=0,test=0; | |
142 | Float_t dle=0; | |
143 | Float_t sigcor=0; | |
144 | Int_t ndev=evt->GetNdevices(); | |
145 | for (Int_t idev=1; idev<=ndev; idev++) | |
146 | { | |
147 | omt=(IceAOM*)evt->GetDevice(idev); | |
148 | if (!omt) continue; | |
149 | idtrans=omt->GetUniqueID(); | |
150 | ||
151 | // Also take bad transmitter modules into account | |
152 | ibad=omt->GetDeadValue("ADC"); | |
153 | if (ibad) omt->SetAlive("ADC"); | |
154 | ||
155 | // Check for corresponding receiver modules | |
156 | for (Int_t jdev=1; jdev<=ndev; jdev++) | |
157 | { | |
158 | // No Xtalk from a module to itself | |
159 | if (jdev==idev) continue; | |
160 | ||
161 | omr=(IceAOM*)evt->GetDevice(jdev); | |
162 | if (!omr) continue; | |
163 | idrec=omr->GetUniqueID(); | |
164 | ||
165 | fxtalk=(TF1*)fOmdb->GetObject(idtrans,idrec+1); | |
166 | if (!fxtalk) continue; | |
167 | ||
168 | // Determine Xtalk probability for each transmitter hit | |
169 | for (Int_t ithit=1; ithit<=omt->GetNhits(); ithit++) | |
170 | { | |
171 | AliSignal* st=omt->GetHit(ithit); | |
172 | if (!st) continue; | |
173 | ||
174 | adct=st->GetSignal("ADC",-4); // Get uncalibrated amplitude | |
175 | dlemin=fxtalk->GetParameter("dLE-min"); | |
176 | dlemax=fxtalk->GetParameter("dLE-max"); | |
177 | // Protection against overflow in Xtalk prob. function | |
178 | cpar=fxtalk->GetParameter("C"); | |
179 | bpar=fxtalk->GetParameter("B"); | |
180 | test=(adct-cpar)/bpar; | |
181 | if (test>100) | |
182 | { | |
183 | p=1; | |
184 | } | |
185 | else if (test<-100) | |
186 | { | |
187 | p=0; | |
188 | } | |
189 | else | |
190 | { | |
191 | p=fxtalk->Eval(adct); | |
192 | } | |
193 | if (p<fPmin) continue; | |
194 | ||
195 | // Xtalk flagging for each receiver hit | |
196 | for (Int_t irhit=1; irhit<=omr->GetNhits(); irhit++) | |
197 | { | |
198 | AliSignal* sr=omr->GetHit(irhit); | |
199 | if (!sr) continue; | |
200 | ||
201 | // Check calibrated LE time differences | |
202 | if (!ibad) | |
203 | { | |
204 | let=st->GetSignal("LE",4); | |
205 | ler=sr->GetSignal("LE",4); | |
206 | dle=ler-let; | |
207 | if (dle<dlemin || dle>dlemax) continue; | |
208 | } | |
209 | // Register this receiver hit to be corrected | |
210 | xhits.Add(sr); | |
211 | } | |
212 | } // end of transmitter hit loop | |
213 | } // end of receiver OM loop | |
214 | ||
215 | // Restore the original transmitter dead flag value | |
216 | if (ibad) omt->SetDead("ADC"); | |
217 | } // end of transmitter OM loop | |
218 | ||
219 | // Perform the Xtalk signal correction to the registered receiver hits | |
220 | for (Int_t ix=0; ix<xhits.GetEntries(); ix++) | |
221 | { | |
222 | AliSignal* sx=(AliSignal*)xhits.At(ix); | |
223 | if (!sx) continue; | |
224 | adcr=sx->GetSignal("ADC"); | |
225 | sigcor=fPe; | |
226 | // If stored ADC data is un-calibrated, convert fPe to raw ADC value | |
227 | AliSignal* parent=(AliSignal*)sx->GetDevice(); | |
228 | if (parent) | |
229 | { | |
230 | if (parent->GetCalFunction("ADC")); | |
231 | { | |
232 | idrec=parent->GetUniqueID(); | |
233 | omr=(IceAOM*)fOmdb->GetObject(idrec,1); | |
234 | TF1* fdecal=0; | |
235 | if (omr) fdecal=omr->GetDecalFunction("ADC"); | |
236 | if (fdecal) sigcor=fdecal->Eval(fPe); | |
237 | } | |
238 | } | |
239 | adcr=adcr-sigcor; | |
240 | sx->SetSignal(adcr,"ADC"); | |
241 | } | |
242 | } | |
243 | /////////////////////////////////////////////////////////////////////////// |