[EMCAL-567] Add class to handle EMCal temperature calibration

- Gain of EMCal cell is temperature dependent.
- The temperature is stored in the ccdb about every 3min for 8 sensors per SM
- New class downloads temperature values from ccdb and averages them per SM
- Per cell, the energy dependence was determined in run2. These values are stored in the ccdb and also read in at initializeFromCCDB
- As the temperature values are accumulated per run, the end of run timestamp is taken - 60s of safety margin

Author: jokonig

Detectors/EMCAL/calibration/CMakeLists.txt

@@ -20,6 +20,7 @@ o2_add_library(EMCALCalibration
                         src/PedestalCalibDevice.cxx
                         src/PedestalProcessorDevice.cxx
                         src/PedestalProcessorData.cxx
+                        src/EMCALTempCalibExtractor.cxx
                PUBLIC_LINK_LIBRARIES O2::CCDB O2::EMCALBase
                                      O2::EMCALCalib
                                      O2::EMCALReconstruction
@@ -46,6 +47,7 @@ o2_target_root_dictionary(EMCALCalibration
                                   include/EMCALCalibration/EMCDCSProcessor.h
                                   include/EMCALCalibration/EMCALPedestalHelper.h
                                   include/EMCALCalibration/PedestalProcessorData.h
+                                  include/EMCALCalibration/EMCALTempCalibExtractor.h
                           LINKDEF src/EMCALCalibrationLinkDef.h)
 
 o2_add_executable(emcal-channel-calib-workflow

Detectors/EMCAL/calibration/include/EMCALCalibration/EMCALTempCalibExtractor.h

@@ -0,0 +1,93 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+/// \class EMCALTempCalibExtractor
+/// \brief  Calculate gain correction factors based on the temperature and the cell-by-cell temperature dependent correction factors (slope and intercept)
+/// \author Joshua König
+/// \ingroup EMCALCalib
+/// \since June 30, 2025
+
+#ifndef EMCALTEMPCALIBEXTRACTOR_H_
+#define EMCALTEMPCALIBEXTRACTOR_H_
+
+#include <algorithm>
+#include <cmath>
+#include <iostream>
+#include "CCDB/BasicCCDBManager.h"
+#include "EMCALCalib/ElmbData.h"
+#include "EMCALCalib/TempCalibrationParams.h"
+#include "EMCALBase/Geometry.h"
+
+namespace o2
+{
+namespace emcal
+{
+
+class EMCALTempCalibExtractor
+{
+
+ public:
+  /// \brief Constructor
+  EMCALTempCalibExtractor()
+  {
+    LOG(info) << "initialized EMCALTempCalibExtractor";
+    try {
+      // Try to access geometry initialized ountside
+      mGeometry = o2::emcal::Geometry::GetInstance();
+    } catch (o2::emcal::GeometryNotInitializedException& e) {
+      mGeometry = o2::emcal::Geometry::GetInstanceFromRunNumber(300000); // fallback option
+    }
+  };
+  /// \brief Destructor
+  ~EMCALTempCalibExtractor() = default;
+
+  /// \brief Initialize temperature data and slope for each cell from the ccdb
+  /// \param path path to the slope data
+  /// \param timestamp timestamp for the ccdb objects or runnumber (will detect automatically if its a runnumber and convert it)
+  void InitializeFromCCDB(std::string path, uint64_t timestamp);
+
+  /// \brief get average temperature in a supermodule
+  /// \param iSM SM number
+  /// \param ElmbData object where temperature sensor values are stored
+  /// \return average temperature in a supermodule
+  float getTemperatureForSM(const unsigned short iSM, o2::emcal::ElmbData* ElmbData) const;
+
+  /// \brief get gain calibration factor depending on the temperature and the slope of the cell
+  /// \param cellID cell ID
+  /// \return gain calibration factor
+  float getGainCalibFactor(const unsigned short cellID) const;
+
+  /// \brief set temperature range in which sensor ddata is assumed to be good
+  /// \param low lower temperature
+  /// \param high upper temperature
+  void setAcceptedEnergyRange(float low, float high);
+
+  /// \brief set if median (true) or mean (false) should be used for averaging of the temperature in a SM
+  void setUseMedian(const bool tmp) { mUseMedian = tmp; }
+
+  /// \brief get sensor IDs for a specific supermodule
+  /// \param iSM SM number
+  /// \return vector of sensor IDs
+  std::vector<unsigned short> getSensorsForSM(const unsigned short iSM) const;
+
+ private:
+  static constexpr unsigned short mNCells = 17664;      ///< Number of EMCal cells
+  std::array<float, mNCells> mGainCalibFactors;         ///< gain calibration factors that are calculated based on the temperature and the slopes for each cell
+  o2::emcal::Geometry* mGeometry;                       ///< pointer to the EMCal geometry
+  std::array<float, 2> mAcceptedTempRange = {15., 30.}; ///< Temperature range where sensors are believed to send good data. Temperatures outside this range will be rejected
+  bool mUseMedian = true;                               /// switch to decide if temperature within a SM should be calculated as the mean or the median of the individual sensor data
+};
+
+} // namespace emcal
+
+} // namespace o2
+
+#endif

Detectors/EMCAL/calibration/src/EMCALTempCalibExtractor.cxx

@@ -0,0 +1,127 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+#include "EMCALCalibration/EMCALTempCalibExtractor.h"
+#include "EMCALCalib/CalibDB.h"
+#include "CCDB/CcdbApi.h"
+#include "CCDB/BasicCCDBManager.h"
+#include <numeric>
+
+namespace o2
+{
+namespace emcal
+{
+
+void EMCALTempCalibExtractor::InitializeFromCCDB(std::string path, uint64_t timestamp)
+{
+
+  auto& ccdbMgr = o2::ccdb::BasicCCDBManager::instance();
+  uint64_t maxRunNr = 1000000;
+  if (timestamp < maxRunNr) {
+    LOG(info) << "assuming input is run " << timestamp << " will convert it to timstamp";
+    auto [sor, eor] = ccdbMgr.getRunDuration(timestamp);
+    uint64_t sixtySec = 60000;
+    timestamp = eor - sixtySec; // safety margin of 1min at EOR
+    LOG(info) << "set timestamp to " << timestamp;
+  }
+
+  o2::emcal::CalibDB calibdb("http://alice-ccdb.cern.ch");
+  std::map<std::string, std::string> metadata;
+  auto tempSensorData = calibdb.readTemperatureSensorData(timestamp, metadata);
+
+  // also obtain cell dependent correction factors
+  TempCalibrationParams* params = ccdbMgr.getForTimeStamp<o2::emcal::TempCalibrationParams>(path, timestamp);
+
+  std::map<unsigned short, float> mapSMTemperature;
+  for (unsigned short i = 0; i < mNCells; ++i) {
+    const unsigned short iSM = mGeometry->GetSuperModuleNumber(i);
+    if (mapSMTemperature.count(iSM) == 0) {
+      mapSMTemperature[iSM] = getTemperatureForSM(iSM, tempSensorData);
+    }
+    float corrFac = params->getTempCalibParamA0(i) + params->getTempCalibParamSlope(i) * mapSMTemperature[iSM];
+    mGainCalibFactors[i] = corrFac;
+  }
+}
+
+float EMCALTempCalibExtractor::getTemperatureForSM(const unsigned short iSM, o2::emcal::ElmbData* ElmbData) const
+{
+  if (iSM < 0 || iSM > 20) {
+    LOG(error) << "SM " << iSM << "does not exist!"; // could be replaced with a proper exception
+    return 0.;
+  }
+  std::vector<unsigned short> vecSensorID = getSensorsForSM(iSM);
+
+  // Obtain temperature for these sensors
+  std::vector<float> vecTemperature;
+  for (const auto& iSensor : vecSensorID) {
+    float temp = ElmbData->getMean(iSensor);
+    if (temp < mAcceptedTempRange[0] || temp > mAcceptedTempRange[1]) {
+      continue;
+    }
+    vecTemperature.push_back(temp);
+  }
+
+  const unsigned int nEntries = vecTemperature.size();
+  if (nEntries == 0) {
+    LOG(warning) << "No sensor data between " << mAcceptedTempRange[0] << " and " << mAcceptedTempRange[1] << "degree found... for SM " << iSM << "  Setting to default 20 degree";
+    return 20.; //
+  }
+
+  // get median energy
+  float tempSM = 0.;
+  if (mUseMedian) {
+    std::sort(vecTemperature.begin(), vecTemperature.end());
+    if (nEntries % 2 == 0) {
+      // even number of elements: average the two middle ones
+      tempSM = (vecTemperature[nEntries / 2 - 1] + vecTemperature[nEntries / 2]) / 2.0;
+    } else {
+      // odd number of elements: return the middle one
+      tempSM = vecTemperature[nEntries / 2];
+    }
+  } else { // use Mean temperature
+    float sum = std::accumulate(vecTemperature.begin(), vecTemperature.end(), 0.0);
+    tempSM = sum / vecTemperature.size();
+  }
+  return tempSM;
+}
+
+float EMCALTempCalibExtractor::getGainCalibFactor(const unsigned short cellID) const
+{
+  if (cellID >= mNCells) {
+    LOG(error) << "cell ID" << cellID << " does not exist";
+    return 1.;
+  }
+  return mGainCalibFactors[cellID];
+}
+
+std::vector<unsigned short> EMCALTempCalibExtractor::getSensorsForSM(const unsigned short iSM) const
+{
+  unsigned short nSensors = 8;
+  if (iSM == 10 || iSM == 11 || iSM == 19 || iSM == 20) {
+    nSensors = 4;
+  }
+
+  std::vector<unsigned short> vecSensorID;
+  for (unsigned short iELMBSensor = iSM * 8; iELMBSensor < iSM * 8 + nSensors; iELMBSensor++) {
+    vecSensorID.push_back(iELMBSensor);
+  }
+  return vecSensorID;
+}
+
+void EMCALTempCalibExtractor::setAcceptedEnergyRange(float low, float high)
+{
+  mAcceptedTempRange[0] = low;
+  mAcceptedTempRange[1] = high;
+}
+
+} // namespace emcal
+
+} // namespace o2