Utility for solving inverse ray-tracing problem. More...

#include <InverseRaytracer.h>

Inheritance diagram for InverseRaytracer:

Collaboration diagram for InverseRaytracer:

[legend]

Classes
struct	CerenkovAngle
	Sine and cosine of Cerenkov angle. More...

struct	Solution
	Solution of inverse ray-tracing. More...

Public Types
enum	ErrorCodes { c_NoPhysicsSolution = -1 , c_NoEquationSolution = -2 , c_NoReflectionPoint = -3 }
	Error codes returned by solveDirect or solveReflected. More...

enum	EGeometry { c_Unified = 0 , c_Segmented = 1 }
	Treatement of quartz geometry. More...

enum	EOptics { c_SemiLinear = 0 , c_Exact = 1 }
	Treatement of spherical mirror optics. More...

Public Member Functions
	InverseRaytracer (int moduleID, double cosTotal)
	Class constructor. More...

void	clear () const
	Clear the solutions to prepare for the new round.

int	solveDirect (double xD, double zD, const TOPTrack::AssumedEmission &assumedEmission, const CerenkovAngle &cer, double step=0) const
	Solve inverse ray-tracing for direct photon. More...

int	solveReflected (double xD, double zD, int Nxm, double xmMin, double xmMax, const TOPTrack::AssumedEmission &assumedEmission, const CerenkovAngle &cer, double step=0) const
	Solve inverse ray-tracing for reflected photon. More...

int	solveForReflectionPoint (double xM, int Nxm, const TOPTrack::AssumedEmission &assumedEmission, const CerenkovAngle &cer) const
	Solve inverse ray-tracing for a given reflection point on the mirror. More...

double	getCosTotal () const
	Returns cosine of total reflection angle. More...

std::vector< Solution > &	getSolutions (unsigned i) const
	Returns the solutions of inverse ray-tracing. More...

bool	getStatus () const
	Returns status. More...

bool	getStatus (unsigned i) const
	Returns status. More...

bool	isNymDifferent () const
	Checks if Nym differs between solutions front and back in at least one of the vectors. More...

PhotonState	getReconstructedPhoton (const Solution &sol, double DFic=0) const
	Returns reconstructed photon at emission for a given solution of inverse raytracing. More...

int	getModuleID () const
	Returns slot ID. More...

EGeometry	getGeometry () const
	Returns quartz geometry treatement. More...

EOptics	getOptics () const
	Returns treatement of spherical mirror optics. More...

const std::vector< BarSegment > &	getBars () const
	Returns geometry data of bar segments. More...

const Mirror &	getMirror () const
	Returns geometry data of spherical mirror. More...

const Prism &	getPrism () const
	Returns geometry data of prism. More...

void	setMirrorCenter (double xc, double yc)
	Sets the mirror center-of-curvature. More...

Static Public Member Functions
static void	setMaxPropagationLen (double maxLen)
	Sets maximal allowed propagation length. More...

Protected Attributes
int	m_moduleID = 0
	slot ID

EGeometry	m_geometry = c_Unified
	quartz geometry

EOptics	m_optics = c_SemiLinear
	spherical mirror optics

std::vector< BarSegment >	m_bars
	geometry data of bar segments

Mirror	m_mirror
	spherical mirror geometry data

Prism	m_prism
	prism geometry data

Private Member Functions
bool	solve (double dxdz, const CerenkovAngle &cer, const TOPTrack::TrackAngles &trk) const
	Solve inverse ray-tracing for unknown azimuthal Cerenkov angle. More...

bool	findReflectionPoint (double xE, double zE, double xD, double zD, double xmMin, double xmMax, double &xM, double &zM, double &dxdz) const
	Finds reflection point on the mirror using semi-linear optics approximation. More...

double	getDeltaXE (double x, double xe, double ze, double xd, double zd) const
	Returns the difference between input xe and the reflected position at given x. More...

Private Attributes
double	m_cosTotal = 0
	cosine of total reflection angle

std::vector< Solution >	m_solutions [2]
	storage for the two solutions

bool	m_ok [2] = {false, false}
	status of solutions

ROOT::Math::XYZPoint	m_emiPoint
	temporary storage of emission point

CerenkovAngle	m_cer
	temporary storage of Cerenkov angle

TOPTrack::TrackAngles	m_trk
	temporary storage of track polar and azimuthal angles

Static Private Attributes
static double	s_maxLen = 10000
	maximal allowed propagation length

Detailed Description

Utility for solving inverse ray-tracing problem.

Definition at line 28 of file InverseRaytracer.h.

Member Enumeration Documentation

◆ EGeometry

enum EGeometry

inherited

Treatement of quartz geometry.

Enumerator
c_Unified	single bar with average width and thickness
c_Segmented	segmented bars

Definition at line 33 of file RaytracerBase.h.

◆ EOptics

enum EOptics

inherited

Treatement of spherical mirror optics.

Enumerator
c_SemiLinear	semi-linear approximation
c_Exact	exact optics

Definition at line 41 of file RaytracerBase.h.

◆ ErrorCodes

enum ErrorCodes

Error codes returned by solveDirect or solveReflected.

Enumerator
c_NoPhysicsSolution	no physics solution
c_NoEquationSolution	no solution of equation
c_NoReflectionPoint	position on the mirror not found

Definition at line 35 of file InverseRaytracer.h.

                       {
         c_NoPhysicsSolution = -1,   
         c_NoEquationSolution = -2,  
         c_NoReflectionPoint = -3    
       };

Constructor & Destructor Documentation

◆ InverseRaytracer()

InverseRaytracer	(	int	moduleID,
		double	cosTotal
	)

inline

Class constructor.

Parameters

moduleID	slot ID
cosTotal	cosine of total reflection angle

Definition at line 133 of file InverseRaytracer.h.

Member Function Documentation

◆ findReflectionPoint()

bool findReflectionPoint	(	double	xE,
		double	zE,
		double	xD,
		double	zD,
		double	xmMin,
		double	xmMax,
		double &	xM,
		double &	zM,
		double &	dxdz
	)		const

private

Finds reflection point on the mirror using semi-linear optics approximation.

Parameters

xE	unfolded emission position in x (unfolding w.r.t mirror)
zE	emission position in z
xD	unfolded detection position in x (unfolding w.r.t mirror)
zD	detection position in z
xmMin	lower limit for search range in x
xmMax	upper limit for search range in x
xM	reflection position in x [out]
zM	reflection position in z [out]
dxdz	photon slope in x-z (dx/dz) before mirror [out]

Returns: true on success

Definition at line 313 of file InverseRaytracer.cc.

     {
       double xe = (xE - m_mirror.xc) / m_mirror.R;
       double ze = (zE - m_mirror.zc) / m_mirror.R;
       double xd = (xD - m_mirror.xc) / m_mirror.R;
       double zd = (zD - m_mirror.zc) / m_mirror.R;
  
       double x1 = (xmMin - m_mirror.xc) / m_mirror.R;
       double y1 = getDeltaXE(x1, xe, ze, xd, zd);
  
       double x2 = (xmMax - m_mirror.xc) / m_mirror.R;
       double y2 = getDeltaXE(x2, xe, ze, xd, zd);
  
       if (y1 * y2 > 0) return false; // no (single) solution
  
       for (int i = 0; i < 20; i++) {
         double x = (x1 + x2) / 2;
         double y = getDeltaXE(x, xe, ze, xd, zd);
         if (y * y1 < 0) {
           x2 = x;
         } else {
           x1 = x;
           y1 = y;
         }
       }
       double x = (x1 + x2) / 2;
       double z = sqrt(1 - x * x);
       xM = x * m_mirror.R + m_mirror.xc;
       zM = z * m_mirror.R + m_mirror.zc;
  
       double kx = (x - xd);
       double kz = (z - zd);
       double s = 2 * (kx * x + kz * z);
       kx -= s * x;
       kz -= s * z;
       dxdz = kx / kz;
  
       return true;
     }

◆ getBars()

const std::vector<BarSegment>& getBars ( ) const

inlineinherited

Returns geometry data of bar segments.

Returns: geometry data of bar segments

Definition at line 161 of file RaytracerBase.h.

◆ getCosTotal()

double getCosTotal ( ) const

inline

Returns cosine of total reflection angle.

Returns: cosine of total reflection angle at mean photon energy for beta = 1

Definition at line 191 of file InverseRaytracer.h.

◆ getDeltaXE()

double getDeltaXE	(	double	x,
		double	xe,
		double	ze,
		double	xd,
		double	zd
	)		const

private

Returns the difference between input xe and the reflected position at given x.

This function is used to find the reflection point on the mirror. All arguments must be given in the mirror frame and in units of mirror radius.

Parameters

x	position in x on the mirror
xe	unfolded emission position in x
ze	emission position in z
xd	unfolded detection position in x
zd	detection position in z

Returns: the difference in units of mirror radius.

Definition at line 300 of file InverseRaytracer.cc.

◆ getGeometry()

EGeometry getGeometry ( ) const

inlineinherited

Returns quartz geometry treatement.

Returns: quartz geometry treatement

Definition at line 149 of file RaytracerBase.h.

◆ getMirror()

const Mirror& getMirror ( ) const

inlineinherited

Returns geometry data of spherical mirror.

Returns: geometry data of spherical mirror

Definition at line 167 of file RaytracerBase.h.

◆ getModuleID()

int getModuleID ( ) const

inlineinherited

Returns slot ID.

Returns: slot ID

Definition at line 143 of file RaytracerBase.h.

◆ getOptics()

EOptics getOptics ( ) const

inlineinherited

Returns treatement of spherical mirror optics.

Returns: spherical mirror optics

Definition at line 155 of file RaytracerBase.h.

◆ getPrism()

const Prism& getPrism ( ) const

inlineinherited

Returns geometry data of prism.

Returns: geometry data of prism

Definition at line 173 of file RaytracerBase.h.

◆ getReconstructedPhoton()

PhotonState getReconstructedPhoton	(	const Solution &	sol,
		double	DFic = `0`
	)		const

Returns reconstructed photon at emission for a given solution of inverse raytracing.

Parameters

sol	solution of inverse raytracing
DFic	additional rotation angle around track (delta Cerenkov azimuthal angle)

Returns: reconstructed photon (note: usually meaningless if status is false!)

Definition at line 356 of file InverseRaytracer.cc.

◆ getSolutions()

std::vector<Solution>& getSolutions ( unsigned i ) const

inline

Returns the solutions of inverse ray-tracing.

Parameters

i	to select first (0) or second (1) solutions

Returns: a vector of solutions

Definition at line 198 of file InverseRaytracer.h.

◆ getStatus() [1/2]

bool getStatus ( void ) const

inline

Returns status.

Returns: status

Definition at line 204 of file InverseRaytracer.h.

◆ getStatus() [2/2]

bool getStatus ( unsigned i ) const

inline

Returns status.

Parameters

i	to select status of first (0) or second (1) solutions

Returns: status

Definition at line 211 of file InverseRaytracer.h.

◆ isNymDifferent()

bool isNymDifferent ( ) const

Checks if Nym differs between solutions front and back in at least one of the vectors.

Returns: true if differs

Definition at line 259 of file InverseRaytracer.cc.

◆ setMaxPropagationLen()

static void setMaxPropagationLen ( double maxLen )

inlinestatic

Sets maximal allowed propagation length.

Parameters

maxLen maximal allowed propagation length

Definition at line 141 of file InverseRaytracer.h.

◆ setMirrorCenter()

void setMirrorCenter	(	double	xc,
		double	yc
	)

inherited

Sets the mirror center-of-curvature.

Parameters

xc	center of curvature in x
yc	center of curvature in y

Definition at line 100 of file RaytracerBase.cc.

◆ solve()

bool solve	(	double	dxdz,
		const CerenkovAngle &	cer,
		const TOPTrack::TrackAngles &	trk
	)		const

private

Solve inverse ray-tracing for unknown azimuthal Cerenkov angle.

Solutions are always two or none (very rare case, phic=0: the two are the same)

Parameters

dxdz	photon slope (dx/dz) in x-z projection
cer	sine and cosine of Cerenkov angle
trk	sine and cosine of track polar and azimuthal angles at photon emission

Returns: true if solutions exits

Definition at line 268 of file InverseRaytracer.cc.

◆ solveDirect()

int solveDirect	(	double	xD,
		double	zD,
		const TOPTrack::AssumedEmission &	assumedEmission,
		const CerenkovAngle &	cer,
		double	step = `0`
	)		const

Solve inverse ray-tracing for direct photon.

Parameters

xD	unfolded position in x of photon at detection plane
zD	position of detection plane
assumedEmission	photon emission position and track angles
cer	sine and cosine of Cerenkov angle
step	step for numerical derivative calculation

Returns: index of solution or ErrorCode on fail

Definition at line 67 of file InverseRaytracer.cc.

◆ solveForReflectionPoint()

int solveForReflectionPoint	(	double	xM,
		int	Nxm,
		const TOPTrack::AssumedEmission &	assumedEmission,
		const CerenkovAngle &	cer
	)		const

Solve inverse ray-tracing for a given reflection point on the mirror.

Parameters

xM	position in x of the reflection point on the mirror.
Nxm	signed number of reflections before mirror
assumedEmission	photon emission position and track angles
cer	sine and cosine of Cerenkov angle

Returns: index of solution or ErrorCode on fail

Definition at line 192 of file InverseRaytracer.cc.

◆ solveReflected()

int solveReflected	(	double	xD,
		double	zD,
		int	Nxm,
		double	xmMin,
		double	xmMax,
		const TOPTrack::AssumedEmission &	assumedEmission,
		const CerenkovAngle &	cer,
		double	step = `0`
	)		const

Solve inverse ray-tracing for reflected photon.

Parameters

xD	unfolded position in x of photon at detection plane (unfolding w.r.t mirror)
zD	position of detection plane
Nxm	signed number of reflections before mirror
xmMin	lower limit for the reflection point search range
xmMax	upper limit for the reflection point search range
assumedEmission	photon emission position and track angles
cer	sine and cosine of Cerenkov angle
step	step for numerical derivative calculation

Returns: index of solution or ErrorCode on fail

Definition at line 108 of file InverseRaytracer.cc.

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

top/reconstruction_cpp/include/InverseRaytracer.h
top/reconstruction_cpp/src/InverseRaytracer.cc

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Member Enumeration Documentation

◆ EGeometry

◆ EOptics

◆ ErrorCodes

Constructor & Destructor Documentation

◆ InverseRaytracer()

Member Function Documentation

◆ findReflectionPoint()

◆ getBars()

◆ getCosTotal()

◆ getDeltaXE()

◆ getGeometry()

◆ getMirror()

◆ getModuleID()

◆ getOptics()

◆ getPrism()

◆ getReconstructedPhoton()

◆ getSolutions()

◆ getStatus() [1/2]

◆ getStatus() [2/2]

◆ isNymDifferent()

◆ setMaxPropagationLen()

◆ setMirrorCenter()

◆ solve()

◆ solveDirect()

◆ solveForReflectionPoint()

◆ solveReflected()