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SolarPos.h
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//# SolarPos.h: Solar position class
//# Copyright (C) 1995,1996,1997,1998
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library is distributed in the hope that it will be useful, but WITHOUT
//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//# Internet email: casa-feedback@nrao.edu.
//# Postal address: AIPS++ Project Office
//# National Radio Astronomy Observatory
//# 520 Edgemont Road
//# Charlottesville, VA 22903-2475 USA
#ifndef MEASURES_SOLARPOS_H
#define MEASURES_SOLARPOS_H
//# Includes
#include <mutex>
#include <casacore/casa/aips.h>
#include <casacore/casa/Quanta/MVPosition.h>
namespace casacore { //# NAMESPACE CASACORE - BEGIN
// <summary> Solar position class and calculations </summary>
// <use visibility=export>
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="tMeasMath" demos="">
// </reviewed>
// <prerequisite>
// <li> <linkto class=Measure>Measure</linkto> class,
// especially <linkto class=MEpoch>MEpoch</linkto>
// <li> <linkto class=MeasData>MeasData</linkto> class for constants
// </prerequisite>
//
// <etymology>
// SolarPos from Solar Position
// </etymology>
//
// <synopsis>
// SolarPos forms the class for Solar Position calculations. It is a simple
// container with the selected method, and the mean epoch.<br>
// The method is selected from one of the following:
// <ul>
// <li> SolarPos::STANDARD (at 1995/09/04 the IAU1980 definition)
// <li> SolarPos::NONE
// </ul>
// Epochs can be specified as the MJD (with defined constants MeasData::MJD2000
// and MeasData::MJDB1950 or the actual MJD),
// leading to the following constructors:
// <ul>
// <li> SolarPos() default; assuming JD2000, IAU1980
// <li> SolarPos(method) assuming the correct default epoch of
// JD2000
// <li> SolarPos(method,epoch) with epoch Double(MJD)
// </ul>
// Actual SolarPos for a certain Epoch is calculated by the () operator
// as SolarPos(epoch), with epoch Double MJD, as an MVPosition vector.<br>
// It returns the geocentric position of the heliocentre in rectangular
// coordinates in AU.<br>
// The derivative (d<sup>-1</sup>) can be obtained as well by
// derivative(epoch), baryEarthDerivative() and barySunDerivative().<br>
// The Earth's and solar barycentric position can be obtained by the
// members <src>baryEarth</src> and <src>barySun</src>.
// The following details can be set with the
// <linkto class=Aipsrc>Aipsrc</linkto> mechanism:
// <ul>
// <li> measures.solarpos.d_interval: approximation interval as time
// (fraction of days is default unit) over which linear approximation
// is used
// <li> measures.solarpos.b_usejpl: use the JPL database for solar position.
// Else analytical expression, relative error about 10<sup>-9</sup>
// Note that the JPL database to be used can be set with
// measures.jpl.ephemeris (at the moment of writing DE200 (default),
// or DE405)
// </ul>
// Reference: M. Soma et al., Cel. Mech. 41 (1988), 389;
// E.M. Standish, Astron. Astroph. 114 (1982), 297.
// </synopsis>
//
// <example>
// </example>
//
// <motivation>
// To calculate the solar/Earth positions for gravitational deflection.
// An alternate route could have been
// a global function, but having a simple container allows
// caching of some calculations for speed.<br>
// Using MJD (JD-2400000.5) rather than JD is for precision reasons.
// </motivation>
//
// <todo asof="1996/02/18">
// </todo>
class SolarPos {
public:
//# Constants
// Interval to be used for linear approximation (in days)
static constexpr Double INTV = 0.04;
//# Enumerations
// Types of known SolarPos calculations (at 1995/09/04 STANDARD == IAU1980)
enum SolarPosTypes {STANDARD,NONE};
//# Constructors
// Default constructor, generates default J2000 SolarPos identification
SolarPos();
// Copy constructor
SolarPos(const SolarPos &other);
// Constructor with type
SolarPos(SolarPosTypes type);
// Copy assignment
SolarPos &operator=(const SolarPos &other);
//# Destructor
~SolarPos();
//# Operators
// Operator () calculates the geocentric Solar Position in AU
const MVPosition&operator()(Double epoch);
//# General Member Functions
// <group>
// Return derivatives of SolarPos (d<sup>-1</sup>)
const MVPosition &derivative (Double epoch);
const MVPosition &baryEarthDerivative (Double epoch);
const MVPosition &barySunDerivative (Double epoch);
// </group>
// Barycentric position of Earth
const MVPosition &baryEarth(Double epoch);
// Barycentric position of Sun
const MVPosition &barySun(Double epoch);
// Re-initialise SolarPos object
// <group>
void init();
void init(SolarPosTypes type);
// </group>
// Refresh calculations
void refresh();
private:
//# Data menbers
// Method to be used
SolarPosTypes method;
// Check epoch for linear approximation
Double checkEpoch = 1e30;
Double checkSunEpoch = 1e30;
// Cached calculated Earth positions
Double eval[3];
// Cached derivatives
Double deval[3];
// Cached calculated Sun positions
Double sval[3];
// Cached derivatives
Double dsval[3];
// To be able to use references in simple calculations, results are calculated
// in a circular buffer.
// Current buffer pointer
Int lres;
// Last calculation
MVPosition result[6];
// Interpolation interval
inline static uInt interval_reg;
// JPL use
inline static uInt usejpl_reg;
inline static std::once_flag initialize_once_flag;
//# Member functions
void copy(const SolarPos &other);
static void initialize_statics();
// Calculate heliocentric Earth position for time t
void calcEarth(Double t);
// Calculate heliocentric barycentre position
void calcSun(Double t);
};
} //# NAMESPACE CASACORE - END
#endif
casacore::type
casacore::MVPosition
Definition MVPosition.h:111
casacore::SolarPos::SolarPos
SolarPos(const SolarPos &other)
Copy constructor.
casacore::SolarPos::init
void init(SolarPosTypes type)
casacore::SolarPos::barySunDerivative
const MVPosition & barySunDerivative(Double epoch)
casacore::SolarPos::result
MVPosition result[6]
Last calculation.
Definition SolarPos.h:178
casacore::SolarPos::refresh
void refresh()
Refresh calculations.
casacore::SolarPos::baryEarth
const MVPosition & baryEarth(Double epoch)
Barycentric position of Earth.
casacore::SolarPos::calcSun
void calcSun(Double t)
Calculate heliocentric barycentre position.
casacore::SolarPos::sval
Double sval[3]
Cached calculated Sun positions.
Definition SolarPos.h:170
casacore::SolarPos::lres
Int lres
To be able to use references in simple calculations, results are calculated in a circular buffer.
Definition SolarPos.h:176
casacore::SolarPos::INTV
static constexpr Double INTV
Interval to be used for linear approximation (in days).
Definition SolarPos.h:114
casacore::SolarPos::copy
void copy(const SolarPos &other)
casacore::SolarPos::checkEpoch
Double checkEpoch
Check epoch for linear approximation.
Definition SolarPos.h:163
casacore::SolarPos::operator()
const MVPosition & operator()(Double epoch)
Operator () calculates the geocentric Solar Position in AU.
casacore::SolarPos::init
void init()
Re-initialise SolarPos object.
casacore::SolarPos::checkSunEpoch
Double checkSunEpoch
Definition SolarPos.h:164
casacore::SolarPos::SolarPosTypes
SolarPosTypes
Types of known SolarPos calculations (at 1995/09/04 STANDARD == IAU1980).
Definition SolarPos.h:118
casacore::SolarPos::STANDARD
@ STANDARD
Definition SolarPos.h:118
casacore::SolarPos::NONE
@ NONE
Definition SolarPos.h:118
casacore::SolarPos::interval_reg
static uInt interval_reg
Interpolation interval.
Definition SolarPos.h:180
casacore::SolarPos::derivative
const MVPosition & derivative(Double epoch)
Return derivatives of SolarPos (d-1).
casacore::SolarPos::initialize_once_flag
static std::once_flag initialize_once_flag
Definition SolarPos.h:183
casacore::SolarPos::usejpl_reg
static uInt usejpl_reg
JPL use.
Definition SolarPos.h:182
casacore::SolarPos::dsval
Double dsval[3]
Cached derivatives.
Definition SolarPos.h:172
casacore::SolarPos::operator=
SolarPos & operator=(const SolarPos &other)
Copy assignment.
casacore::SolarPos::initialize_statics
static void initialize_statics()
casacore::SolarPos::barySun
const MVPosition & barySun(Double epoch)
Barycentric position of Sun.
casacore::SolarPos::method
SolarPosTypes method
Method to be used.
Definition SolarPos.h:161
casacore::SolarPos::~SolarPos
~SolarPos()
casacore::SolarPos::baryEarthDerivative
const MVPosition & baryEarthDerivative(Double epoch)
casacore::SolarPos::calcEarth
void calcEarth(Double t)
Calculate heliocentric Earth position for time t.
casacore::SolarPos::SolarPos
SolarPos(SolarPosTypes type)
Constructor with type.
casacore::SolarPos::SolarPos
SolarPos()
Default constructor, generates default J2000 SolarPos identification.
casacore::SolarPos::deval
Double deval[3]
Cached derivatives.
Definition SolarPos.h:168
casacore::SolarPos::eval
Double eval[3]
Cached calculated Earth positions.
Definition SolarPos.h:166
casacore
this file contains all the compiler specific defines
Definition mainpage.dox:28
casacore::uInt
unsigned int uInt
Definition aipstype.h:49
casacore::Int
int Int
Definition aipstype.h:48
casacore::Double
double Double
Definition aipstype.h:53