/usr/include/casacore/measures/Measures/Nutation.h is in casacore-dev 2.2.0-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 | //# Nutation.h: Nutation class
//# Copyright (C) 1995,1996,1997,1998,2003,2004
//# 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: aips2-request@nrao.edu.
//# Postal address: AIPS++ Project Office
//# National Radio Astronomy Observatory
//# 520 Edgemont Road
//# Charlottesville, VA 22903-2475 USA
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//#
//# $Id$
#ifndef MEASURES_NUTATION_H
#define MEASURES_NUTATION_H
//# Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/Quanta/Quantum.h>
#include <casacore/casa/Quanta/Euler.h>
namespace casacore { //# NAMESPACE CASACORE - BEGIN
//# Forward Declarations
// <summary> Nutation class and calculations </summary>
// <use visibility=export>
// <reviewed reviewer="Tim Cornwell" date="1996/07/01" tests="tMeasMath"
// demos="">
// </reviewed>
// <prerequisite>
// <li> <linkto class=Measure>Measure</linkto> class
// <li> <linkto class=Euler>Euler</linkto>
// <li> <linkto class=MeasData>MeasData</linkto> class for constants
// </prerequisite>
//
// <etymology>
// Nutation
// </etymology>
//
// <synopsis>
// Nutation forms the class for Nutation calculations. It is a simple
// container with the selected method, and the mean epoch.
// It acts as a cache
// for values and their derivatives, to enable fast calculations for time
// epochs close together (see the <em>aipsrc</em> variable
// <em>measures.nutation.d_interval</em>).
//
// The calculation method is selected from one of the following:
// <ul>
// <li> Nutation::STANDARD (at 1995/09/04 the IAU1980 definition,
// from 2004/01/01 IAU2000B)
// <li> Nutation::NONE (nutation of zero returned)
// <li> Nutation::IAU1980
// <li> Nutation::B1950
// <li> Nutation::IAU2000
// <li> Nutation::IAU2000A (equal to the full precision (uas) IAU2000)
// <li> Nutation::IAU2000B (official lower precision (mas) of IAU2000)
// </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> Nutation() default; assuming STANDARD
// <li> Nutation(method)
// </ul>
// Actual Nutation for a certain Epoch is calculated by the () operator
// as Nutation(epoch), with epoch Double MJD. Values are returned as an
// <linkto class=Euler>Euler</linkto>.
// The derivative (d<sup>-1</sup>) can be obtained as well by
// derivative(epoch). <br>
// A Nutation can be re-initialed with a different method and/or zero
// epoch with the <src>init()</src> functions (same format as constructors).
// To bypass the full calculation actual returned values are calculated
// using the derivative if within about 2 hours (error less than about
// 10<sup>-5</sup> mas). A call to refresh() will re-initiate calculations
// from scratch.<br>
// The following details can be set with the
// <linkto class=Aipsrc>Aipsrc</linkto> mechanism:
// <ul>
// <li> measures.nutation.d_interval: approximation interval as time
// (fraction of days is default unit) over which linear approximation
// is used (default 0.04d (about 1 hour)).
// <li> measures.nutation.b_usejpl: use the JPL database nutations for
// IAU1980.
// 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)
// <li> measures.nutation.b_useiers: use the IERS Database nutation
// corrections for IAU1980 (default False)
// </ul>
// </synopsis>
//
// <example>
// <srcblock>
// #include <casacore/measures/Measures.h>
// MVDirection pos(Quantity(10,"degree"),Quantity(-10.5,"degree"));
// // direction RA=10; DEC=-10.5
// Nutation mine(Nutation::IAU1980); // define nutation type
// RotMatrix rotat(mine(45837.0)); // rotation matrix for 84/05/17
// MVDirection new = rotat*pos; // apply nutation
// </srcblock>
// The normal way to use Nutation is by using the
// <linkto class=MeasConvert>MeasConvert</linkto> class.
// </example>
//
// <motivation>
// To calculate the Nutation angles. 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="2003/10/20">
// <li> Correct deval_p (derivative complimentary eqox terms)
// <li> Improve speed by a bit more lazyness in derivative calculations
// and separate eqox calculations
// </todo>
class Nutation {
public:
//# Constants
// Interval to be used for linear approximation (in days)
static const Double INTV;
//# Enumerations
// Types of known Nutation calculations (at 1995/09/04 STANDARD == IAU1980,
// after 2004/01/01 it will be IAU2000B))
enum NutationTypes {
NONE, IAU1980, B1950, IAU2000A, IAU2000B,
IAU2000 = IAU2000A,
STANDARD = IAU1980 };
//# Constructors
// Default constructor, generates default J2000 Nutation identification
Nutation();
// Copy constructor
Nutation(const Nutation &other);
// Constructor with type
explicit Nutation(NutationTypes type);
// Copy assignment
Nutation &operator=(const Nutation &other);
//# Destructor
~Nutation();
//# Operators
// Return the Nutation angles
const Euler &operator()(Double epoch);
//# General Member Functions
// Return derivative of Nutation (d<sup>-1</sup>)
const Euler &derivative(Double epoch);
// Re-initialise Nutation object
// <group>
void init();
void init(NutationTypes type);
// </group>
// Refresh calculations
void refresh();
// Get the equation of equinox
// <group>
Double eqox(Double epoch) ;
Quantity getEqoxAngle(Double epoch);
Quantity getEqoxAngle(Double epoch, const Unit &unit) ;
// </group>
// Get the derivative of the equation of equinoxes in d<sup>-1</sup>
Double derivativeEqox(Double epoch);
// Get the complimentary terms of the equation of equinoxes
Double eqoxCT(Double epoch);
// Get the derivative of the complimentary terms of the equation of equinoxes
Double derivativeEqoxCT(Double epoch);
private:
//# Data members
// Method to be used
NutationTypes method_p;
// Check epoch for linear approximation
Double checkEpoch_p;
// Check epoch for calculation of derivatives
Double checkDerEpoch_p;
// Cached calculated angles
Double nval_p[3];
// Cached derivatives
Double dval_p[3];
// Cached equation of equinoxes
Double eqeq_p;
// Cached derivative equation of equinoxes
Double deqeq_p;
// Cached complimentary terms equation of equinoxes
Double neval_p;
// Cached derivative of complimentary terms equation of equinoxes
Double deval_p;
// To be able to use references rather than copies, and also to use these
// references in simple (up to 4 terms of Nutation results) expressions,
// results are calculated in circulating buffer
Int lres_p;
// Last calculation
Euler result_p[4];
// Interpolation interval
static uInt myInterval_reg;
// IERS use
static uInt myUseiers_reg;
// JPL use
static uInt myUsejpl_reg;
//# Member functions
// Make a copy
void copy(const Nutation &other);
// Fill an empty copy
void fill();
// Calculate Nutation angles for time t; also derivatives if True given
void calcNut(Double t, Bool calcDer = False);
};
} //# NAMESPACE CASACORE - END
#endif
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