kstars

ksplanetbase.cpp

00001 /***************************************************************************
00002                           ksplanetbase.cpp  -  K Desktop Planetarium
00003                              -------------------
00004     begin                : Sun Jul 22 2001
00005     copyright            : (C) 2001 by Jason Harris
00006     email                : jharris@30doradus.org
00007  ***************************************************************************/
00008 
00009 /***************************************************************************
00010  *                                                                         *
00011  *   This program is free software; you can redistribute it and/or modify  *
00012  *   it under the terms of the GNU General Public License as published by  *
00013  *   the Free Software Foundation; either version 2 of the License, or     *
00014  *   (at your option) any later version.                                   *
00015  *                                                                         *
00016  ***************************************************************************/
00017 
00018 #include <math.h>
00019 
00020 #include <qfile.h>
00021 #include <qpoint.h>
00022 #include <qwmatrix.h>
00023 
00024 #include "ksplanetbase.h"
00025 #include "ksplanet.h"
00026 #include "kstarsdata.h"
00027 #include "ksutils.h"
00028 #include "ksnumbers.h"
00029 #include "kspopupmenu.h"
00030 
00031 
00032 KSPlanetBase::KSPlanetBase( KStarsData *kd, QString s, QString image_file, double pSize )
00033  : SkyObject( 2, 0.0, 0.0, 0.0, s, "" ), Rearth(0.0), Image(0), data(kd) {
00034 
00035      if (! image_file.isEmpty()) {
00036         QFile imFile;
00037 
00038         if ( KSUtils::openDataFile( imFile, image_file ) ) {
00039             imFile.close();
00040             Image0.load( imFile.name() );
00041             Image = Image0.convertDepth( 32 );
00042             Image0 = Image;
00043         }
00044     }
00045     PositionAngle = 0.0;
00046     ImageAngle = 0.0;
00047     PhysicalSize = pSize;
00048     Trail.setAutoDelete( TRUE );
00049 }
00050 
00051 void KSPlanetBase::EquatorialToEcliptic( const dms *Obliquity ) {
00052     findEcliptic( Obliquity, ep.longitude, ep.latitude );
00053 }
00054 
00055 void KSPlanetBase::EclipticToEquatorial( const dms *Obliquity ) {
00056     setFromEcliptic( Obliquity, &ep.longitude, &ep.latitude );
00057 }
00058 
00059 void KSPlanetBase::updateCoords( KSNumbers *num, bool includePlanets, const dms *lat, const dms *LST ){
00060     if ( includePlanets ) {
00061         data->earth()->findPosition( num ); //since we don't pass lat & LST, localizeCoords will be skipped
00062 
00063         if ( lat && LST ) {
00064             findPosition( num, lat, LST, data->earth() );
00065             if ( hasTrail() ) Trail.removeLast();
00066         } else {
00067             findGeocentricPosition( num, data->earth() );
00068         }
00069     }
00070 }
00071 
00072 void KSPlanetBase::findPosition( const KSNumbers *num, const dms *lat, const dms *LST, const KSPlanetBase *Earth ) {
00073     findGeocentricPosition( num, Earth );  //private function, reimplemented in each subclass
00074 
00075     if ( Earth ) setRearth( Earth );
00076 
00077     if ( lat && LST )
00078         localizeCoords( num, lat, LST ); //correct for figure-of-the-Earth
00079 
00080     if ( hasTrail() ) {
00081         Trail.append( new SkyPoint( ra(), dec() ) );
00082         if ( Trail.count() > MAXTRAIL ) Trail.removeFirst();
00083     }
00084 
00085     if ( isMajorPlanet() )
00086         findMagnitude(num);
00087 }
00088 
00089 bool KSPlanetBase::isMajorPlanet() const {
00090     if ( name() == "Mercury" || name() == "Venus" || name() == "Mars" ||
00091                 name() == "Jupiter" || name() == "Saturn" || name() == "Uranus" ||
00092                 name() == "Neptune" || name() == "Pluto" )
00093         return true;
00094     return false;
00095 }
00096 
00097 void KSPlanetBase::localizeCoords( const KSNumbers *num, const dms *lat, const dms *LST ) {
00098     //convert geocentric coordinates to local apparent coordinates (topocentric coordinates)
00099     dms HA, HA2; //Hour Angle, before and after correction
00100     double rsinp, rcosp, u, sinHA, cosHA, sinDec, cosDec, D;
00101     double cosHA2;
00102     double r = Rearth * AU_KM; //distance from Earth, in km
00103     u = atan( 0.996647*tan( lat->radians() ) );
00104     rsinp = 0.996647*sin( u );
00105     rcosp = cos( u );
00106     HA.setD( LST->Degrees() - ra()->Degrees() );
00107     HA.SinCos( sinHA, cosHA );
00108     dec()->SinCos( sinDec, cosDec );
00109 
00110     D = atan( ( rcosp*sinHA )/( r*cosDec/6378.14 - rcosp*cosHA ) );
00111     dms temp;
00112     temp.setRadians( ra()->radians() - D );
00113     setRA( temp );
00114 
00115     HA2.setD( LST->Degrees() - ra()->Degrees() );
00116     cosHA2 = cos( HA2.radians() );
00117     temp.setRadians( atan( cosHA2*( r*sinDec/6378.14 - rsinp )/( r*cosDec*cosHA/6378.14 - rcosp ) ) );
00118     setDec( temp );
00119 
00120     EquatorialToEcliptic( num->obliquity() );
00121 }
00122 
00123 void KSPlanetBase::setRearth( const KSPlanetBase *Earth ) {
00124     double sinL, sinB, sinL0, sinB0;
00125     double cosL, cosB, cosL0, cosB0;
00126     double x,y,z;
00127 
00128     //The Moon's Rearth is set in its findGeocentricPosition()...
00129     if ( name() == "Moon" ) {
00130         return;
00131     }
00132 
00133     if ( name() == "Earth" ) {
00134         Rearth = 0.0;
00135         return;
00136     }
00137 
00138     if ( ! Earth && name() != "Moon" ) {
00139         kdDebug() << i18n( "KSPlanetBase::setRearth():  Error: Need an Earth pointer.  (" ) << name() << ")" << endl;
00140         Rearth = 1.0;
00141         return;
00142     }
00143 
00144     Earth->ecLong()->SinCos( sinL0, cosL0 );
00145     Earth->ecLat()->SinCos( sinB0, cosB0 );
00146     double eX = Earth->rsun()*cosB0*cosL0;
00147     double eY = Earth->rsun()*cosB0*sinL0;
00148     double eZ = Earth->rsun()*sinB0;
00149 
00150     helEcLong()->SinCos( sinL, cosL );
00151     helEcLat()->SinCos( sinB, cosB );
00152     x = rsun()*cosB*cosL - eX;
00153     y = rsun()*cosB*sinL - eY;
00154     z = rsun()*sinB - eZ;
00155 
00156     Rearth = sqrt(x*x + y*y + z*z);
00157 
00158     //Set angular size, in arcmin
00159     AngularSize = asin(PhysicalSize/Rearth/AU_KM)*60.*180./dms::PI;
00160 }
00161 
00162 void KSPlanetBase::updateTrail( dms *LST, const dms *lat ) {
00163     for ( SkyPoint *sp = Trail.first(); sp; sp = Trail.next() )
00164         sp->EquatorialToHorizontal( LST, lat );
00165 }
00166 
00167 void KSPlanetBase::findPA( const KSNumbers *num ) {
00168     //Determine position angle of planet (assuming that it is aligned with
00169     //the Ecliptic, which is only roughly correct).
00170     //Displace a point along +Ecliptic Latitude by 1 degree
00171     SkyPoint test;
00172     dms newELat( ecLat()->Degrees() + 1.0 );
00173     test.setFromEcliptic( num->obliquity(), ecLong(), &newELat );
00174     double dx = test.ra()->Degrees() - ra()->Degrees();
00175     double dy = dec()->Degrees() - test.dec()->Degrees();
00176     double pa;
00177     if ( dy ) {
00178         pa = atan( dx/dy )*180.0/dms::PI;
00179     } else {
00180         pa = 90.0;
00181         if ( dx > 0 ) pa = -90.0;
00182     }
00183     setPA( pa );
00184 }
00185 
00186 void KSPlanetBase::rotateImage( double imAngle ) {
00187     ImageAngle = imAngle;
00188     QWMatrix m;
00189     m.rotate( ImageAngle );
00190     Image = Image0.xForm( m );
00191 }
00192 
00193 void KSPlanetBase::scaleRotateImage( int scale, double imAngle ) {
00194     ImageAngle = imAngle;
00195     QWMatrix m;
00196     m.rotate( ImageAngle );
00197     Image = Image0.xForm( m ).smoothScale( scale, scale );
00198 }
00199 
00200 void KSPlanetBase::findMagnitude(const KSNumbers *num) {
00201     
00202     double cosDec, sinDec;
00203     dec()->SinCos(cosDec, sinDec);
00204     
00205     /* Phase of the planet in degrees */
00206     double earthSun = 1.;
00207     double cosPhase = (rsun()*rsun() + rearth()*rearth() - earthSun*earthSun) 
00208       / (2 * rsun() * rearth() );   
00209     double phase = acos ( cosPhase ) * 180.0 / dms::PI;
00210 
00211     /* Computation of the visual magnitude (V band) of the planet.
00212     * Algorithm provided by Pere Planesas (Observatorio Astronomico Nacional)
00213     * It has some simmilarity to J. Meeus algorithm in Astronomical Algorithms, Chapter 40.
00214     * */
00215 
00216     // Initialized to the faintest magnitude observable with the HST
00217     float magnitude = 30;
00218 
00219     double param = 5 * log10(rsun() * rearth() );
00220     double f1 = phase/100.;
00221 
00222     if ( name() == "Mercury" ) {
00223         if ( phase > 150. ) f1 = 1.5; 
00224         magnitude = -0.36 + param + 3.8*f1 - 2.73*f1*f1 + 2*f1*f1*f1;
00225     }
00226     if ( name() =="Venus")
00227         magnitude = -4.29 + param + 0.09*f1 + 2.39*f1*f1 - 0.65*f1*f1*f1;
00228     if( name() == "Mars")
00229         magnitude = -1.52 + param + 0.016*phase; 
00230     if( name() == "Jupiter") 
00231         magnitude = -9.25 + param + 0.005*phase;  
00232 
00233     if( name() == "Saturn") {
00234         double T = num->julianCenturies();
00235         double a0 = (40.66-4.695*T)* dms::PI / 180.;
00236         double d0 = (83.52+0.403*T)* dms::PI / 180.;
00237         double sinx = -cos(d0)*cosDec*cos(a0 - ra()->radians());
00238         sinx = fabs(sinx-sin(d0)*sinDec);
00239         double rings = -2.6*sinx + 1.25*sinx*sinx;
00240         magnitude = -8.88 + param + 0.044*phase + rings;  
00241     }
00242 
00243     if( name() == "Uranus")
00244         magnitude = -7.19 + param + 0.0028*phase;  
00245     if( name() == "Neptune")
00246         magnitude = -6.87 + param;
00247     if( name() == "Pluto" )
00248         magnitude = -1.01 + param + 0.041*phase;
00249 
00250     setMag(magnitude);
00251 }
kstars

ksplanetbase.cpp

kstars

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