Class for computing aerosol scattering and attenuation using simple parameterizations. More...

#include <ParametricXMLMieModel.h>

Inheritance diagram for atm::ParametricXMLMieModel:

Classes
struct	PFParameters
	Phase function table (modified Henyey-Greenstein function). More...

Public Member Functions
atm::AttenuationResult	EvaluateMieAttenuation (const utl::Point &xInit, const utl::Point &xFinal, const std::vector< double > &wLength) const
	Calculate the aerosol attenuation between two points. More...

double	EvaluateMieAttenuation (const utl::Point &xInit, const utl::Point &xFinal, const double wLength) const
	Calculate the attenuation between two points at a single wavelength. Uses a basic three-parameter aerosol model. More...

atm::ScatteringResult	EvaluateMieScattering (const utl::Point &xA, const utl::Point &xB, const double angle, const double distance, const std::vector< double > &wLength) const
	Aerosol scattering fraction in a wavelength band. More...

atm::ScatteringResult	EvaluateMieScattering (const utl::Point &xA, const utl::Point &xB, const double angle, const double distance, const atm::AttenuationResult &mieAttenuation) const
	Aerosol scattering fraction in a wavelength band using precomputed attenuation. More...

double	EvaluateMieScattering (const utl::Point &xA, const utl::Point &xB, const double angle, const double distance, const double wLength) const
	Aerosol scattering fraction at a fixed wavelength. More...

double	EvaluateMieScattering (const utl::Point &xA, const utl::Point &xB, const double angle, const double distance, const double wLength, const double mieAttenuation) const
	Aerosol scattering fraction at a fixed wavelength with precomputed attenuation. More...

double	EvaluateScatteringAngle (const utl::Point &p, const double angle, const double wLength) const
	Calculation is done independent of the position and wavelength. More...

virtual const utl::VRandomSampler &	EvaluateScatteringAngleDistribution (const utl::Point &p, const double wLength) const

double	GetAngstromCoeff () const

double	GetAttenuationLength (const utl::Point &p, const double wLength) const
	Horizontal attenuation length (inverse of extinction coefficient). Grows with altitude as aerosol distribution decreases. More...

double	GetGroundHeightASL () const

double	GetHorizAttLength () const

double	GetMixHeight () const

double	GetScaleHeight () const

double	GetVerticalAerosolOpticalDepth (const unsigned int eyeId, const double altitude) const
	Calculate VAOD at some altitude (w.r.t. sea level) above a given eye. More...

bool	HasData () const
	True if a data source is for the given model. More...

void	Init ()

void	SetAngstromCoeff (const double gamma)

void	SetGroundHeightASL (const double hGnd)

void	SetHorizAttLength (const double lMix)

void	SetMixHeight (const double hMix)

void	SetScaleHeight (const double hScl)

virtual void	SetUncertaintyBound (const double nSigma) const
	alter Model by nSigma standard deviations More...

virtual	~ParametricXMLMieModel ()
	Destructor - should be virtual for base classes. More...

Private Types
typedef struct atm::ParametricXMLMieModel::PFParameters	PFParameters
	Phase function table (modified Henyey-Greenstein function). More...

Private Member Functions
	REGISTER_MODEL (atm::VMieModel,"ParametricXML", ParametricXMLMieModel)

Private Attributes
double	fGamma
	Angstrom exponent of the aerosol scattering wavelength dependence. More...

double	fGammaError

double	fHGnd
	Prevailing ground height used in the aerosol model. More...

double	fHMix
	Mixing layer height (w.r.t. prevailing ground level). More...

double	fHMixError

double	fHScl
	Scale height of the aerosol "entrainment layer" above the mixing layer. More...

double	fHSclError

double	fLMix
	Mixing layer (i.e., ground-level) horizontal attenuation length. More...

double	fLMixError

PFParameters	fPhaseFunction

Detailed Description

Class for computing aerosol scattering and attenuation using simple parameterizations.

Author: Luis Prado Jr

This class computes aerosol scattering and extinction properties using basic aerosol models also employed by the HiRes experiment.

For attenuation and VAOD, a simple three-parameter model is used for the altitude dependence of the extinction coefficient. The model splits the aerosol distribution into two layers: a uniform layer of height $h_M$ above ground level where aerosols have been mixed by convection; and an entrainment layer for all $h>h_M$ where the aerosol density decreases exponentially with scale height $H$ . More specifically,

$\alpha(h) = \begin{cases} \alpha_M, & h\leq h_M \\ \alpha_M\ e^{-(h - h_M)/H}, & h>h_M \end{cases}$

where $\alpha_M=1/l_M$ is the extinction coefficient within the mixing layer. For ease of use, this input to the model is given in terms of the horizontal attenuation length $l_M$ of aerosol extinction.

The optical depth between altitudes $h_1$ and $h_2$ is

$\tau(h_1,h_2) = \int_{h_1}^{h_2} \alpha(h') dh' = \begin{cases} \alpha_M\left(h_2-h_1\right), & h_1\leq h_M\text{ and }h_2\leq h_M \\ \alpha_M\left(h_M-h_1 + H(1-e^{-(h_2-h_M)/H})\right), & h_1\leq h_M\text{ and }h_2>h_M \\ \alpha_M H \left(e^{-(h_1-h_M)/H}-e^{-(h_2-h_M)/H}\right), & h_1>h_M\text{ and } h_2>h_M \end{cases}$

Note that in this expression, all heights are expressed with respect to the prevailing ground level of the SD ( $h=0$ ), and not with respect to sea level. Possible differences between aerosols at different locations around the SD, as well as small changes in the terrain, are ignored.

When the height of the mixing layer is set to zero, the extinction coefficient and optical depth reduce to the two-parameter expression given by P. Sokolsky in the appendix to "Introduction to Ultrahigh Energy Cosmic Ray Physics," Westview Press 1988. This was the actual model used by HiRes.

The wavelength dependence of scattering is given by the power-law Angstrom coefficient $\gamma$ :

$\tau(\lambda) = \tau(\lambda_0)\left(\frac{\lambda_0}{\lambda}\right)^\gamma$

where $\lambda_0$ =355 nm. See A. Angstrom, Geo. Anal. 12 (1929) 130-159.

For angular scattering, the model uses a numerically estimated phase function due to Longtin (1988). The calculation uses a desert atmosphere with sand, water droplets, and carbonaceous particles to estimate the phase function at 550 nm under a range of wind conditions. (The current values originate in the calculation performed with winds of 10 m/s.) Details can be found in:

Steven Mengzhi Luo, "Tropospheric Aerosol Study by Fly's Eye and Lidar Technique," PhD Thesis, University of Utah (1992).

Definition at line 19 of file ParametricXMLMieModel.h.

Member Typedef Documentation

typedef struct atm::ParametricXMLMieModel::PFParameters atm::ParametricXMLMieModel::PFParameters

private

Phase function table (modified Henyey-Greenstein function).

Constructor & Destructor Documentation

virtual atm::ParametricXMLMieModel::~ParametricXMLMieModel ( )

inlinevirtual

Destructor - should be virtual for base classes.

Definition at line 23 of file ParametricXMLMieModel.h.

Member Function Documentation

AttenuationResult ParametricXMLMieModel::EvaluateMieAttenuation	(	const utl::Point &	xInit,
		const utl::Point &	xFinal,
		const std::vector< double > &	wLength
	)		const

virtual

Calculate the aerosol attenuation between two points.

Todo:: Propagation of uncertainties of the parameters.

Implements atm::VMieModel.

Definition at line 171 of file ParametricXMLMieModel.cc.

References utl::TabulatedFunctionErrors::PushBack().

Referenced by atm::SuperMieModel::EvaluateMieAttenuation().

double ParametricXMLMieModel::EvaluateMieAttenuation	(	const utl::Point &	xInit,
		const utl::Point &	xFinal,
		const double	wLength
	)		const

virtual

Calculate the attenuation between two points at a single wavelength. Uses a basic three-parameter aerosol model.

Implements atm::VMieModel.

Definition at line 195 of file ParametricXMLMieModel.cc.

References utl::abs(), utl::ReferenceEllipsoid::eWGS84, utl::ReferenceEllipsoid::Get(), utl::kLn10, utl::m, max, utl::nanometer, utl::ReferenceEllipsoid::PointToLatitudeLongitudeHeight(), std::pow(), and utl::swap().

ScatteringResult ParametricXMLMieModel::EvaluateMieScattering	(	const utl::Point &	xA,
		const utl::Point &	xB,
		const double	angle,
		const double	distance,
		const std::vector< double > &	wLength
	)		const

virtual

Aerosol scattering fraction in a wavelength band.

Implements atm::VMieModel.

Definition at line 93 of file ParametricXMLMieModel.cc.

Referenced by atm::SuperMieModel::EvaluateMieScattering(), and testParametricXMLMieModel::testExpertMode().

ScatteringResult ParametricXMLMieModel::EvaluateMieScattering	(	const utl::Point &	xA,
		const utl::Point &	xB,
		const double	angle,
		const double	distance,
		const atm::AttenuationResult &	mieAttenuation
	)		const

virtual

Aerosol scattering fraction in a wavelength band using precomputed attenuation.

Implements atm::VMieModel.

Definition at line 109 of file ParametricXMLMieModel.cc.

References utl::TabulatedFunction::GetNPoints(), atm::AttenuationResult::GetTransmissionFactor(), utl::TabulatedFunction::GetX(), utl::TabulatedFunction::GetY(), and utl::TabulatedFunctionErrors::PushBack().

double ParametricXMLMieModel::EvaluateMieScattering	(	const utl::Point &	xA,
		const utl::Point &	xB,
		const double	angle,
		const double	distance,
		const double	wLength
	)		const

virtual

Aerosol scattering fraction at a fixed wavelength.

Implements atm::VMieModel.

Definition at line 136 of file ParametricXMLMieModel.cc.

double ParametricXMLMieModel::EvaluateMieScattering	(	const utl::Point &	xA,
		const utl::Point &	xB,
		const double	angle,
		const double	distance,
		const double	wLength,
		const double	mieAttenuation
	)		const

virtual

Aerosol scattering fraction at a fixed wavelength with precomputed attenuation.

Implements atm::VMieModel.

Definition at line 153 of file ParametricXMLMieModel.cc.

References std::pow().

double ParametricXMLMieModel::EvaluateScatteringAngle	(	const utl::Point &	p,
		const double	angle,
		const double	wLength
	)		const

virtual

Calculation is done independent of the position and wavelength.

Implements atm::VMieModel.

Definition at line 311 of file ParametricXMLMieModel.cc.

References RdGeoCeLDFFitter::a, RdGeoCeLDFFitter::b, RdGeoCeLDFFitter::c, utl::kPi, and std::pow().

Referenced by atm::SuperMieModel::EvaluateScatteringAngle().

const utl::VRandomSampler & VMieModel::EvaluateScatteringAngleDistribution	(	const utl::Point &	p,
		const double	wLength
	)		const

virtualinherited

Definition at line 35 of file VMieModel.cc.

References utl::deg, atm::VMieModel::EvaluateScatteringAngle(), atm::VMieModel::fAngularDistribution, and utl::TabulatedFunction::PushBack().

double atm::ParametricXMLMieModel::GetAngstromCoeff ( ) const

inline

Definition at line 83 of file ParametricXMLMieModel.h.

References fGamma.

Referenced by testParametricXMLMieModel::testExpertMode().

double ParametricXMLMieModel::GetAttenuationLength	(	const utl::Point &	p,
		const double	wLength
	)		const

virtual

Horizontal attenuation length (inverse of extinction coefficient). Grows with altitude as aerosol distribution decreases.

Implements atm::VMieModel.

Definition at line 287 of file ParametricXMLMieModel.cc.

References utl::ReferenceEllipsoid::eWGS84, utl::ReferenceEllipsoid::Get(), utl::nanometer, utl::ReferenceEllipsoid::PointToLatitudeLongitudeHeight(), and std::pow().

Referenced by atm::SuperMieModel::GetAttenuationLength().

double atm::ParametricXMLMieModel::GetGroundHeightASL ( ) const

inline

Definition at line 86 of file ParametricXMLMieModel.h.

References fHGnd.

double atm::ParametricXMLMieModel::GetHorizAttLength ( ) const

inline

Definition at line 74 of file ParametricXMLMieModel.h.

References fLMix.

Referenced by testParametricXMLMieModel::testExpertMode().

double atm::ParametricXMLMieModel::GetMixHeight ( ) const

inline

Definition at line 77 of file ParametricXMLMieModel.h.

References fHMix.

Referenced by testParametricXMLMieModel::testExpertMode().

double atm::ParametricXMLMieModel::GetScaleHeight ( ) const

inline

Definition at line 80 of file ParametricXMLMieModel.h.

References fHScl.

Referenced by testParametricXMLMieModel::testExpertMode().

double ParametricXMLMieModel::GetVerticalAerosolOpticalDepth	(	const unsigned int	eyeId,
		const double	altitude
	)		const

virtual

Calculate VAOD at some altitude (w.r.t. sea level) above a given eye.

Implements atm::VMieModel.

Definition at line 251 of file ParametricXMLMieModel.cc.

References utl::ReferenceEllipsoid::eWGS84, utl::ReferenceEllipsoid::Get(), utl::m, and utl::ReferenceEllipsoid::PointToLatitudeLongitudeHeight().

Referenced by atm::SuperMieModel::GetVerticalAerosolOpticalDepth().

bool atm::ParametricXMLMieModel::HasData ( ) const

inlinevirtual

True if a data source is for the given model.

This method is meant to be checked to determine whether the given model is able to find valid data to evaluate. Typically it will always be true for parametric models which rely on an XML file, and will be true or false for database-based models, depending on whether or not relevant data are found in the DB for the current detector time

Implements atm::VModel.

Definition at line 88 of file ParametricXMLMieModel.h.

void ParametricXMLMieModel::Init ( void )

virtual

Implements atm::VModel.

Definition at line 47 of file ParametricXMLMieModel.cc.

References utl::ReferenceEllipsoid::eWGS84, fwk::CoordinateSystemRegistry::Get(), utl::ReferenceEllipsoid::Get(), utl::Branch::GetChild(), utl::Branch::GetData(), utl::Branch::GetTopBranch(), and utl::ReferenceEllipsoid::PointToLatitudeLongitudeHeight().

Referenced by atm::SuperMieModel::Init(), and testParametricXMLMieModel::testExpertMode().

atm::ParametricXMLMieModel::REGISTER_MODEL	(	atm::VMieModel	,
		"ParametricXML"	,
		ParametricXMLMieModel
	)

private

void atm::ParametricXMLMieModel::SetAngstromCoeff ( const double gamma )

inline

Definition at line 82 of file ParametricXMLMieModel.h.

References fGamma.

void atm::ParametricXMLMieModel::SetGroundHeightASL ( const double hGnd )

inline

Definition at line 85 of file ParametricXMLMieModel.h.

References fHGnd.

void atm::ParametricXMLMieModel::SetHorizAttLength ( const double lMix )

inline

Definition at line 73 of file ParametricXMLMieModel.h.

References fLMix.

Referenced by testParametricXMLMieModel::testExpertMode().

void atm::ParametricXMLMieModel::SetMixHeight ( const double hMix )

inline

Definition at line 76 of file ParametricXMLMieModel.h.

References fHMix.

void atm::ParametricXMLMieModel::SetScaleHeight ( const double hScl )

inline

Definition at line 79 of file ParametricXMLMieModel.h.

References fHScl.

Referenced by testParametricXMLMieModel::testExpertMode().

void VModel::SetUncertaintyBound ( const double nSigma ) const

virtualinherited

alter Model by nSigma standard deviations

Reimplemented in atm::MeasuredDBMieModel, and atm::SuperMieModel.

Definition at line 11 of file VModel.cc.

References ERROR.

Member Data Documentation

double atm::ParametricXMLMieModel::fGamma

private

Angstrom exponent of the aerosol scattering wavelength dependence.

Definition at line 104 of file ParametricXMLMieModel.h.

Referenced by GetAngstromCoeff(), and SetAngstromCoeff().

double atm::ParametricXMLMieModel::fGammaError

private

Definition at line 105 of file ParametricXMLMieModel.h.

double atm::ParametricXMLMieModel::fHGnd

private

Prevailing ground height used in the aerosol model.

Definition at line 108 of file ParametricXMLMieModel.h.

Referenced by GetGroundHeightASL(), and SetGroundHeightASL().

double atm::ParametricXMLMieModel::fHMix

private

Mixing layer height (w.r.t. prevailing ground level).

Definition at line 96 of file ParametricXMLMieModel.h.

Referenced by GetMixHeight(), and SetMixHeight().

double atm::ParametricXMLMieModel::fHMixError

private

Definition at line 97 of file ParametricXMLMieModel.h.

double atm::ParametricXMLMieModel::fHScl

private

Scale height of the aerosol "entrainment layer" above the mixing layer.

Definition at line 100 of file ParametricXMLMieModel.h.

Referenced by GetScaleHeight(), and SetScaleHeight().

double atm::ParametricXMLMieModel::fHSclError

private

Definition at line 101 of file ParametricXMLMieModel.h.

double atm::ParametricXMLMieModel::fLMix

private

Mixing layer (i.e., ground-level) horizontal attenuation length.

Definition at line 92 of file ParametricXMLMieModel.h.

Referenced by GetHorizAttLength(), and SetHorizAttLength().

double atm::ParametricXMLMieModel::fLMixError

private

Definition at line 93 of file ParametricXMLMieModel.h.

PFParameters atm::ParametricXMLMieModel::fPhaseFunction

private

Definition at line 118 of file ParametricXMLMieModel.h.

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

Classes

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation