DriftLengthEstimator Struct Reference

Helper construct implementing the (re)estimation of the drift length for various hit objects. More...

#include <DriftLengthEstimator.h>

Public Member Functions
void	exposeParameters (ModuleParamList *moduleParamList, const std::string &prefix)
	Add the parameters of the estimator to the module.
double	updateDriftLength (CDCRecoHit2D &recoHit2D)
	Update the drift length of the reconstructed hit in place.
double	updateDriftLength (CDCRecoHit3D &recoHit3D, double tanLambda)
	Update the drift length of the reconstructed hit in place.
void	updateDriftLength (CDCFacet &facet)
	Reestimate the drift length of all three contained drift circles. More...
void	updateDriftLength (CDCSegment2D &segment)
	Update the drift length of the contained reconstructed hit in place.
void	updateDriftLength (CDCSegment3D &segment, double tanLambda)
	Update the drift length of the contained reconstructed hit in place.
void	updateDriftLength (CDCTrack &track, double tanLambda)
	Update the drift length of the contained reconstructed hit in place.

Public Attributes
bool	m_param_useAlphaInDriftLength = true
	Parameter : Switch to serve the alpha angle to the drift length translator.
double	m_param_tofMassScale = NAN
	Parameter : Mass to estimate the velocity in the flight time to the hit.

Detailed Description

Helper construct implementing the (re)estimation of the drift length for various hit objects.

Definition at line 38 of file DriftLengthEstimator.h.

Member Function Documentation

updateDriftLength()

void updateDriftLength

(

CDCFacet &

facet

)

Reestimate the drift length of all three contained drift circles.

Using the additional flight direction information the accuracy of the drift length can be increased alot helping the filters following this step

Definition at line 90 of file DriftLengthEstimator.cc.

{
  CDC::RealisticTDCCountTranslator tdcCountTranslator;
  const FlightTimeEstimator& flightTimeEstimator = FlightTimeEstimator::instance();
 
  const UncertainParameterLine2D& line = facet.getFitLine();
  Vector2D flightDirection = line->tangential();
  Vector2D centralPos2D = line->closest(facet.getMiddleWire().getRefPos2D());
  double alpha = centralPos2D.angleWith(flightDirection);
  if (not m_param_useAlphaInDriftLength) {
    alpha = 0;
  }
 
  auto doUpdate = [&](CDCRLWireHit & rlWireHit, Vector2D recoPos2D) {
    const CDCWire& wire = rlWireHit.getWire();
    const CDCHit* hit = rlWireHit.getWireHit().getHit();
    const bool rl = rlWireHit.getRLInfo() == ERightLeft::c_Right;
    const double beta = 1;
    double flightTimeEstimate = flightTimeEstimator.getFlightTime2D(recoPos2D, alpha, beta);
    double driftLength = tdcCountTranslator.getDriftLength(hit->getTDCCount(),
                                                           wire.getWireID(),
                                                           flightTimeEstimate,
                                                           rl,
                                                           wire.getRefZ(),
                                                           alpha);
    rlWireHit.setRefDriftLength(driftLength);
  };
 
  doUpdate(facet.getStartRLWireHit(), facet.getStartRecoPos2D());
  doUpdate(facet.getMiddleRLWireHit(), facet.getMiddleRecoPos2D());
  doUpdate(facet.getEndRLWireHit(), facet.getEndRecoPos2D());
 
  // More accurate implementation
  // double startDriftLength = updateDriftLength(facet.getStartRecoHit2D());
  // facet.getStartRLWireHit().setRefDriftLength(startDriftLength);
 
  // double middleDriftLength = updateDriftLength(facet.getMiddleRecoHit2D());
  // facet.getMiddleRLWireHit().setRefDriftLength(middleDriftLength);
 
  // double endDriftLength = updateDriftLength(facet.getEndRecoHit2D());
  // facet.getEndRLWireHit().setRefDriftLength(endDriftLength);
}

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The documentation for this struct was generated from the following files:

• tracking/trackFindingCDC/eventdata/utils/include/DriftLengthEstimator.h
• tracking/trackFindingCDC/eventdata/utils/src/DriftLengthEstimator.cc