diff options
Diffstat (limited to 'kstars/kstars/skypoint.h')
| -rw-r--r-- | kstars/kstars/skypoint.h | 498 |
1 files changed, 498 insertions, 0 deletions
diff --git a/kstars/kstars/skypoint.h b/kstars/kstars/skypoint.h new file mode 100644 index 00000000..ee3cf09c --- /dev/null +++ b/kstars/kstars/skypoint.h @@ -0,0 +1,498 @@ +/*************************************************************************** + skypoint.h - K Desktop Planetarium + ------------------- + begin : Sun Feb 11 2001 + copyright : (C) 2001-2005 by Jason Harris + email : jharris@30doradus.org + copyright : (C) 2004-2005 by Pablo de Vicente + email : p.devicente@wanadoo.es + ***************************************************************************/ + +/*************************************************************************** + * * + * This program is free software; you can redistribute it and/or modify * + * it under the terms of the GNU General Public License as published by * + * the Free Software Foundation; either version 2 of the License, or * + * (at your option) any later version. * + * * + ***************************************************************************/ + +#ifndef SKYPOINT_H +#define SKYPOINT_H + +#include <qstring.h> +#include <qptrlist.h> + +#include "dms.h" + +/**@class SkyPoint + * + *The sky coordinates of a point in the sky. The + *coordinates are stored in both Equatorial (Right Ascension, + *Declination) and Horizontal (Azimuth, Altitude) coordinate systems. + *Provides set/get functions for each coordinate angle, and functions + *to convert between the Equatorial and Horizon coordinate systems. + * + *Because the coordinate values change slowly over time (due to + *precession, nutation), the "catalog coordinates" are stored + *(RA0, Dec0), which were the true coordinates on Jan 1, 2000. + *The true coordinates (RA, Dec) at any other epoch can be found + *from the catalog coordinates using updateCoords(). + *@short Stores dms coordinates for a point in the sky. + *for converting between coordinate systems. + *@author Jason Harris + *@version 1.0 + */ + +class KSNumbers; +class CSegment; +class SkyObject; + +class SkyPoint { +public: +/**Default constructor: Sets RA, Dec and RA0, Dec0 according + *to arguments. Does not set Altitude or Azimuth. + *@param r Right Ascension + *@param d Declination + */ + SkyPoint( const dms& r, const dms& d ) { set( r, d ); } + +/**Alternate constructor using pointer arguments, for convenience. + *It behaves essentially like the default constructor. + *@param r Right Ascension pointer + *@param d Declination pointer + */ + SkyPoint( const dms *r, const dms *d ) { set( dms(*r), dms(*d) ); } + +/**Alternate constructor using double arguments, for convenience. + *It behaves essentially like the default constructor. + *@param r Right Ascension, expressed as a double + *@param d Declination, expressed as a double + */ + SkyPoint( double r=0.0, double d=0.0 ) { set( r, d ); } + +/** + *Empty destructor. + */ + virtual ~SkyPoint(); + +//// +//// 1. Setting Coordinates +//// ======================= + +/**Sets RA, Dec and RA0, Dec0 according to arguments. + *Does not set Altitude or Azimuth. + *@param r Right Ascension + *@param d Declination + */ + void set( const dms& r, const dms& d ); + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param r Right Ascension + *@param d Declination + */ + void set( const dms *r, const dms *d ) { set( *r, *d ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param r Right Ascension + *@param d Declination + */ + void set( double r, double d ); + +/**Sets RA0, the catalog Right Ascension. + *@param r catalog Right Ascension. + */ + void setRA0( dms r ) { RA0.set( r ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param r Right Ascension, expressed as a double. + */ + void setRA0( double r ) { RA0.setH( r ); } + +/**Sets Dec0, the catalog Declination. + *@param d catalog Declination. + */ + void setDec0( dms d ) { Dec0.set( d ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param d Declination, expressed as a double. + */ + void setDec0( double d ) { Dec0.setD( d ); } + +/**Sets RA, the current Right Ascension. + *@param r Right Ascension. + */ + void setRA( dms r ) { RA.set( r ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param r Right Ascension, expressed as a double. + */ + void setRA( double r ) { RA.setH( r ); } + +/**Sets Dec, the current Declination + *@param d Declination. + */ + void setDec( dms d ) { Dec.set( d ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param d Declination, expressed as a double. + */ + void setDec( double d ) { Dec.setD( d ); } + +/**Sets Alt, the Altitude. + *@param alt Altitude. + */ + void setAlt( dms alt ) { Alt.set( alt ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param alt Altitude, expressed as a double. + */ + void setAlt( double alt ) { Alt.setD( alt ); } + +/**Sets Az, the Azimuth. + *@param az Azimuth. + */ + void setAz( dms az ) { Az.set( az ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param az Azimuth, expressed as a double. + */ + void setAz( double az ) { Az.setD( az ); } + +/**Sets Galactic Longitude. + *@param glo Galactic Longitude. + */ +// void setGalLong( dms glo ) { galLong.set( glo ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param glo Galactic Longitude, expressed as a double. + */ +// void setGalLong( double glo ) { galLong.setD( glo ); } + +/**Sets Galactic Longitude. + *@param gla Galactic Longitude. + */ +// void setGalLat( dms gla ) { galLat.set( gla ); } + +/**Overloaded member function, provided for convenience. + *It behaves essentially like the above function. + *@param gla Galactic Longitude, expressed as a double. + */ +// void setGalLat( double gla ) { galLat.setD( gla ); } + +//// +//// 2. Returning coordinates. +//// ========================= + +/**@return a pointer to the catalog Right Ascension. + */ + const dms* ra0() const { return &RA0; } + +/**@return a pointer to the catalog Declination. + */ + const dms* dec0() const { return &Dec0; } + +/**@returns a pointer to the current Right Ascension. + */ + const dms* ra() const { return &RA; } + +/**@return a pointer to the current Declination. + */ + const dms* dec() const { return &Dec; } + +/**@return a pointer to the current Azimuth. + */ + const dms* az() const { return &Az; } + +/**@return a pointer to the current Altitude. + */ + const dms* alt() const { return &Alt; } + +/**@return a pointer to the current galactic latitude. + */ +// const dms* gLat() const { return &galLat; } + +/**@return a pointer to the current galactic longitude. + */ +// const dms* gLong() const { return &galLong; } + +//// +//// 3. Coordinate conversions. +//// ========================== + +/**Determine the (Altitude, Azimuth) coordinates of the + *SkyPoint from its (RA, Dec) coordinates, given the local + *sidereal time and the observer's latitude. + *@param LST pointer to the local sidereal time + *@param lat pointer to the geographic latitude + */ + void EquatorialToHorizontal( const dms* LST, const dms* lat ); + +/**Determine the (RA, Dec) coordinates of the + *SkyPoint from its (Altitude, Azimuth) coordinates, given the local + *sidereal time and the observer's latitude. + *@param LST pointer to the local sidereal time + *@param lat pointer to the geographic latitude + */ + void HorizontalToEquatorial( const dms* LST, const dms* lat ); + + /**@short Convert Right Ascension/Declination to Ecliptic logitude/latitude. + */ + void EquatorialToEcliptic( const KSNumbers *num ); + + /**@short Convert Ecliptic logitude/latitude to Right Ascension/Declination. + */ + + void EclipticToEquatorial( const KSNumbers *num ); + +/**Determine the Ecliptic coordinates of the SkyPoint, given the Julian Date. + *The ecliptic coordinates are returned as reference arguments (since + *they are not stored internally) + */ + void findEcliptic( const dms *Obliquity, dms &EcLong, dms &EcLat ); + +/**Set the current (RA, Dec) coordinates of the + *SkyPoint, given pointers to its Ecliptic (Long, Lat) coordinates, and + *to the current obliquity angle (the angle between the equator and ecliptic). + */ + void setFromEcliptic( const dms *Obliquity, const dms *EcLong, const dms *EcLat ); + +/** Computes galactic coordinates from equatorial coordinates referred to + * epoch 1950. RA and Dec are, therefore assumed to be B1950 + * coordinates. + */ + void Equatorial1950ToGalactic(dms &galLong, dms &galLat); + +/** Computes equatorial coordinates referred to 1950 from galactic ones referred to + * epoch B1950. RA and Dec are, therefore assumed to be B1950 + * coordinates. + */ + void GalacticToEquatorial1950(const dms* galLong, const dms* galLat); + +//// +//// 4. Coordinate update/corrections. +//// ================================= + +/**Determine the current coordinates (RA, Dec) from the catalog + *coordinates (RA0, Dec0), accounting for both precession and nutation. + *@param num pointer to KSNumbers object containing current values of + *time-dependent variables. + *@param includePlanets does nothing in this implementation (see KSPlanetBase::updateCoords()). + *@param lat does nothing in this implementation (see KSPlanetBase::updateCoords()). + *@param LST does nothing in this implementation (see KSPlanetBase::updateCoords()). + */ + virtual void updateCoords( KSNumbers *num, bool includePlanets=true, const dms *lat=0, const dms *LST=0 ); + +/**Computes the apparent coordinates for this SkyPoint for any epoch, + *accounting for the effects of precession, nutation, and aberration. + *Similar to updateCoords(), but the starting epoch need not be + *J2000, and the target epoch need not be the present time. + *@param jd0 Julian Day which identifies the original epoch + *@param jdf Julian Day which identifies the final epoch + */ + void apparentCoord(long double jd0, long double jdf); + +/**Determine the effects of nutation for this SkyPoint. + *@param num pointer to KSNumbers object containing current values of + *time-dependent variables. + */ + void nutate(const KSNumbers *num); + +/**Determine the effects of aberration for this SkyPoint. + *@param num pointer to KSNumbers object containing current values of + *time-dependent variables. + */ + void aberrate(const KSNumbers *num); + +/**General case of precession. It precess from an original epoch to a + *final epoch. In this case RA0, and Dec0 from SkyPoint object represent + *the coordinates for the original epoch and not for J2000, as usual. + *@param jd0 Julian Day which identifies the original epoch + *@param jdf Julian Day which identifies the final epoch + */ + void precessFromAnyEpoch(long double jd0, long double jdf); + + /** Determine the E-terms of aberration + *In the past, the mean places of stars published in catalogs included + *the contribution to the aberration due to the ellipticity of the orbit + *of the Earth. These terms, known as E-terms were almost constant, and + *in the newer catalogs (FK5) are not included. Therefore to convert from + *FK4 to FK5 one has to compute these E-terms. + */ + SkyPoint Eterms(void); + + /** Exact precession from Besselian epoch 1950 to epoch J2000. The + *coordinates referred to the first epoch are in the + FK4 catalog, while the latter are in the Fk5 one. + *Reference: Smith, C. A.; Kaplan, G. H.; Hughes, J. A.; Seidelmann, + *P. K.; Yallop, B. D.; Hohenkerk, C. Y. + *Astronomical Journal, vol. 97, Jan. 1989, p. 265-279 + *This transformation requires 4 steps: + * - Correct E-terms + * - Precess from B1950 to 1984, January 1st, 0h, using Newcomb expressions + * - Add zero point correction in right ascension for 1984 + * - Precess from 1984, January 1st, 0h to J2000 + */ + void B1950ToJ2000(void); + + /** Exact precession from epoch J2000 Besselian epoch 1950. The coordinates + *referred to the first epoch are in the FK4 catalog, while the + *latter are in the Fk5 one. + *Reference: Smith, C. A.; Kaplan, G. H.; Hughes, J. A.; Seidelmann, + *P. K.; Yallop, B. D.; Hohenkerk, C. Y. + *Astronomical Journal, vol. 97, Jan. 1989, p. 265-279 + *This transformation requires 4 steps: + * - Precess from J2000 to 1984, January 1st, 0h + * - Add zero point correction in right ascension for 1984 + * - Precess from 1984, January 1st, 0h, to B1950 using Newcomb expressions + * - Correct E-terms + */ + void J2000ToB1950(void); + + /** Coordinates in the FK4 catalog include the effect of aberration due + *to the ellipticity of the orbit of the Earth. Coordinates in the FK5 + *catalog do not include these terms. In order to convert from B1950 (FK4) + *to actual mean places one has to use this function. + */ + void addEterms(void); + + /** Coordinates in the FK4 catalog include the effect of aberration due + *to the ellipticity of the orbit of the Earth. Coordinates in the FK5 + *catalog do not include these terms. In order to convert from + * FK5 coordinates to B1950 (FK4) one has to use this function. + */ + void subtractEterms(void); + + /** Computes the angular distance between two SkyObjects. The algorithm + * to compute this distance is: + * cos(distance) = sin(d1)*sin(d2) + cos(d1)*cos(d2)*cos(a1-a2) + * where a1,d1 are the coordinates of the first object and a2,d2 are + * the coordinates of the second object. + * However this algorithm is not accurate when the angular separation + * is small. + * Meeus provides a different algorithm in page 111 which we + * implement here. + * @param sp SkyPoint to which distance is to be calculated + * @return dms angle representing angular separation. + **/ + + dms angularDistanceTo( SkyPoint *sp); + + bool operator == ( SkyPoint &p ) { return ( ra()->Degrees() == p.ra()->Degrees() && dec()->Degrees() == p.dec()->Degrees() ); } + + /** Computes the velocity of the Sun projected on the direction of the source. + * + * @param jd Epoch expressed as julian day to which the source coordinates refer to. + * @return Radial velocity of the source referred to the barycenter of the solar system in km/s + **/ + double vRSun(long double jd); + + /** Computes the radial velocity of a source referred to the solar system barycenter + * from the radial velocity referred to the + * Local Standard of Rest, aka known as VLSR. To compute it we need the coordinates of the + * source the VLSR and the epoch for the source coordinates. + * + * @param vlsr radial velocity of the source referred to the LSR in km/s + * @param jd Epoch expressed as julian day to which the source coordinates refer to. + * @return Radial velocity of the source referred to the barycenter of the solar system in km/s + **/ + double vHeliocentric(double vlsr, long double jd); + + /** Computes the radial velocity of a source referred to the Local Standard of Rest, also known as VLSR + * from the radial velocity referred to the solar system barycenter + * + * @param vhelio radial velocity of the source referred to the LSR in km/s + * @param jd Epoch expressed as julian day to which the source coordinates refer to. + * @return Radial velocity of the source referred to the barycenter of the solar system in km/s + **/ + double vHelioToVlsr(double vhelio, long double jd); + + /** Computes the velocity of any object projected on the direction of the source. + * @param jd0 Julian day for which we compute the direction of the source + * @return velocity of the Earth projected on the direction of the source kms-1 + */ + double vREarth(long double jd0); + + /** Computes the radial velocity of a source referred to the center of the earth + * from the radial velocity referred to the solar system barycenter + * + * @param vhelio radial velocity of the source referred to the barycenter of the + * solar system in km/s + * @param jd Epoch expressed as julian day to which the source coordinates refer to. + * @return Radial velocity of the source referred to the center of the Earth in km/s + **/ + double vGeocentric(double vhelio, long double jd); + + /** Computes the radial velocity of a source referred to the solar system barycenter + * from the velocity referred to the center of the earth + * + * @param vgeo radial velocity of the source referred to the center of the Earth + * [km/s] + * @param jd Epoch expressed as julian day to which the source coordinates refer to. + * @return Radial velocity of the source referred to the solar system barycenter in km/s + **/ + double vGeoToVHelio(double vgeo, long double jd); + + /** Computes the velocity of any object (oberver's site) projected on the + * direction of the source. + * @param vsite velocity of that object in cartesian coordinates + * @return velocity of the object projected on the direction of the source kms-1 + */ + double vRSite(double vsite[3]); + + /** Computes the radial velocity of a source referred to the observer site on the surface + * of the earth from the geocentric velovity and the velocity of the site referred to the center + * of the Earth. + * + * @param vgeo radial velocity of the source referred to the center of the earth in km/s + * @param vsite Velocity at which the observer moves referred to the center of the earth. + * @return Radial velocity of the source referred to the observer's site in km/s + **/ + double vTopocentric(double vgeo, double vsite[3]); + + /** Computes the radial velocity of a source referred to the center of the Earth from + * the radial velocity referred to an observer site on the surface of the earth + * + * @param vtopo radial velocity of the source referred to the observer's site in km/s + * @param vsite Velocity at which the observer moves referred to the center of the earth. + * @return Radial velocity of the source referred the center of the earth in km/s + **/ + double vTopoToVGeo(double vtopo, double vsite[3]); + +//// +//// 5. Calculating Rise/Set/Transit data. +//// ===================================== + +//// To Be Moved from SkyObject.... + +//// +//// 6. Constellation Identification +//// ===================================== + + QString constellation( QPtrList<CSegment> &seglist, QPtrList<SkyObject> &cnames ) const; + + +protected: +/**Precess this SkyPoint's catalog coordinates to the epoch described by the + *given KSNumbers object. + *@param num pointer to a KSNumbers object describing the target epoch. + */ + void precess(const KSNumbers *num); + + +private: + dms RA0, Dec0; //catalog coordinates + dms RA, Dec; //current true sky coordinates + dms Alt, Az; +}; + +#endif |