casacore
Aberration.h
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1//# Aberration.h: Aberration class
2//# Copyright (C) 1995,1996,1997,1998
3//# Associated Universities, Inc. Washington DC, USA.
4//#
5//# This library is free software; you can redistribute it and/or modify it
6//# under the terms of the GNU Library General Public License as published by
7//# the Free Software Foundation; either version 2 of the License, or (at your
8//# option) any later version.
9//#
10//# This library is distributed in the hope that it will be useful, but WITHOUT
11//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
13//# License for more details.
14//#
15//# You should have received a copy of the GNU Library General Public License
16//# along with this library; if not, write to the Free Software Foundation,
17//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
18//#
19//# Correspondence concerning AIPS++ should be addressed as follows:
20//# Internet email: aips2-request@nrao.edu.
21//# Postal address: AIPS++ Project Office
22//# National Radio Astronomy Observatory
23//# 520 Edgemont Road
24//# Charlottesville, VA 22903-2475 USA
25//#
26//#
27//# $Id$
28
29#ifndef MEASURES_ABERRATION_H
30#define MEASURES_ABERRATION_H
31
32//# Includes
33#include <casacore/casa/aips.h>
34#include <casacore/casa/Quanta/MVPosition.h>
35
36
37namespace casacore { //# NAMESPACE CASACORE - BEGIN
38
39// <summary>
40// Aberration class and calculations
41// </summary>
42
43// <use visibility=export>
44
45// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="tMeasMath" demos="">
46// </reviewed>
47
48// <prerequisite>
49// <li> <linkto class=Measure>Measure</linkto> class,
50// especially <linkto class=MEpoch>MEpoch</linkto>
51// <li> <linkto class=MeasData>MeasData</linkto> class for constants
52// </prerequisite>
53//
54// <etymology>
55// Aberration
56// </etymology>
57//
58// <synopsis>
59// Aberration forms the class for Aberration calculations. It is a simple
60// container with the selected method, and the mean epoch.<br>
61// The method is selected from one of the following:
62// <ul>
63// <li> Aberration::STANDARD (at 1995/09/04 the IAU1980 definition)
64// <li> Aberration::NONE
65// <li> Aberration::B1950
66// </ul>
67// Epochs can be specified as the MJD (with defined constants MeasData::MJD2000
68// and MeasData::MJDB1950 or the actual MJD),
69// leading to the following constructors:
70// <ul>
71// <li> Aberration() default; assuming JD2000, IAU1980
72// <li> Aberration(method) assuming the correct default epoch of
73// JD2000 or B1950
74// <li> Aberration(method,epoch) with epoch Double(MJD).
75// </ul>
76// Actual Aberration for a certain Epoch is calculated by the () operator
77// as Aberration(epoch), with epoch Double MJD, values returned as an
78// MVPosition.<br>
79// The derivative (d<sup>-1</sup>) can be obtained as well by
80// derivative(epoch).<br>
81// The following details can be set with the
82// <linkto class=Aipsrc>Aipsrc</linkto> mechanism:
83// <ul>
84// <li> measures.aberration.d_interval: approximation interval as time
85// (fraction of days is default unit) over which linear approximation
86// is used
87// <li> measures.aberration.b_usejpl: use the JPL database values for IAU1980.
88// Else analytical expression, relative error about 10<sup>-9</sup>
89// Note that the JPL database to be used can be set with
90// measures.jpl.ephemeris (at the moment of writing DE200 (default),
91// or DE405). If using the JPL database, the d_interval (and the
92// output of derivative()) are irrelevant.
93// </ul>
94// </synopsis>
95//
96// <example>
97// </example>
98//
99// <motivation>
100// To calculate the Aberration angles. An alternate route could have been
101// a global function, but having a simple container allows
102// caching of some calculations for speed.<br>
103// Using MJD (JD-2400000.5) rather than JD is for precision reasons.
104// </motivation>
105//
106// <todo asof="1997/12/02">
107// </todo>
108
110{
111public:
112//# Constants
113// Interval to be used for linear approximation (in days)
114 static const Double INTV;
115
116//# Enumerations
117// Types of known Aberration calculations (at 1995/09/04 STANDARD == IAU1980)
119
120//# Constructors
121// Default constructor, generates default J2000 Aberration identification
123// Copy constructor
124 Aberration(const Aberration &other);
125// Constructor with type
127// Copy assignment
129
130//# Destructor
132
133//# Operators
134// Operator () calculates the Aberration direction cosine vector
136
137//# General Member Functions
138// Return derivative of Aberration (d<sup>-1</sup>) w.r.t. time
140
141// Re-initialise Aberration object
142// <group>
143 void init();
145// </group>
146
147// Refresh calculations
148 void refresh();
149
150private:
151//# Data menbers
152// Method to be used
154// Check epoch for linear approximation
156// Cached calculated angles
158// Cached derivatives
160// To be able to use referenced results in simple calculations, a circular
161// result buffer is used.
162// Current buffer pointer.
164// Last calculation
166// Interpolation interval
168// JPL use
170
171//# Member functions
172// Copy
173 void copy(const Aberration &other);
174// Fill an empty copy
175 void fill();
176// Calculate Aberration angles for time t
178};
179
180
181} //# NAMESPACE CASACORE - END
182
183#endif
184
185
Aberration & operator=(const Aberration &other)
Copy assignment.
void calcAber(Double t)
Calculate Aberration angles for time t.
Double dval[3]
Cached derivatives.
Definition: Aberration.h:159
Aberration(const Aberration &other)
Copy constructor.
void copy(const Aberration &other)
Copy.
MVPosition result[4]
Last calculation.
Definition: Aberration.h:165
void fill()
Fill an empty copy.
Double checkEpoch
Check epoch for linear approximation.
Definition: Aberration.h:155
Aberration()
Default constructor, generates default J2000 Aberration identification.
static uInt usejpl_reg
JPL use.
Definition: Aberration.h:169
static uInt interval_reg
Interpolation interval.
Definition: Aberration.h:167
AberrationTypes method
Method to be used.
Definition: Aberration.h:153
static const Double INTV
Interval to be used for linear approximation (in days)
Definition: Aberration.h:114
Double aval[3]
Cached calculated angles.
Definition: Aberration.h:157
const MVPosition & operator()(Double epoch)
Operator () calculates the Aberration direction cosine vector.
Int lres
To be able to use referenced results in simple calculations, a circular result buffer is used.
Definition: Aberration.h:163
void refresh()
Refresh calculations.
void init()
Re-initialise Aberration object.
AberrationTypes
Types of known Aberration calculations (at 1995/09/04 STANDARD == IAU1980)
Definition: Aberration.h:118
void init(AberrationTypes type)
Aberration(AberrationTypes type)
Constructor with type.
const MVPosition & derivative(Double epoch)
Return derivative of Aberration (d-1) w.r.t.
this file contains all the compiler specific defines
Definition: mainpage.dox:28
unsigned int uInt
Definition: aipstype.h:51
int Int
Definition: aipstype.h:50
double Double
Definition: aipstype.h:55