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tdeedu/kstars/kstars/skypoint.cpp

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/***************************************************************************
skypoint.cpp - 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. *
* *
***************************************************************************/
#include <kdebug.h>
#include <klocale.h>
#include "skypoint.h"
#include "skyobject.h"
#include "dms.h"
#include "ksnumbers.h"
#include "csegment.h"
void SkyPoint::set( const dms& r, const dms& d ) {
RA0.set( r );
Dec0.set( d );
RA.set( r );
Dec.set( d );
}
void SkyPoint::set( double r, double d ) {
RA0.setH( r );
Dec0.setD( d );
RA.setH( r );
Dec.setD( d );
}
SkyPoint::~SkyPoint(){
}
void SkyPoint::EquatorialToHorizontal( const dms *LST, const dms *lat ) {
double AltRad, AzRad;
double sindec, cosdec, sinlat, coslat, sinHA, cosHA;
double sinAlt, cosAlt;
dms HourAngle = LST->Degrees() - ra()->Degrees();
lat->SinCos( sinlat, coslat );
dec()->SinCos( sindec, cosdec );
HourAngle.SinCos( sinHA, cosHA );
sinAlt = sindec*sinlat + cosdec*coslat*cosHA;
AltRad = asin( sinAlt );
cosAlt = cos( AltRad );
double arg = ( sindec - sinlat*sinAlt )/( coslat*cosAlt );
if ( arg <= -1.0 ) AzRad = dms::PI;
else if ( arg >= 1.0 ) AzRad = 0.0;
else AzRad = acos( arg );
if ( sinHA > 0.0 ) AzRad = 2.0*dms::PI - AzRad; // resolve acos() ambiguity
Alt.setRadians( AltRad );
Az.setRadians( AzRad );
}
void SkyPoint::HorizontalToEquatorial( const dms *LST, const dms *lat ) {
double HARad, DecRad;
double sinlat, coslat, sinAlt, cosAlt, sinAz, cosAz;
double sinDec, cosDec;
lat->SinCos( sinlat, coslat );
alt()->SinCos( sinAlt, cosAlt );
Az.SinCos( sinAz, cosAz );
sinDec = sinAlt*sinlat + cosAlt*coslat*cosAz;
DecRad = asin( sinDec );
cosDec = cos( DecRad );
Dec.setRadians( DecRad );
double x = ( sinAlt - sinlat*sinDec )/( coslat*cosDec );
//Under certain circumstances, x can be very slightly less than -1.0000, or slightly
//greater than 1.0000, leading to a crash on acos(x). However, the value isn't
//*really* out of range; it's a kind of roundoff error.
if ( x < -1.0 && x > -1.000001 ) HARad = dms::PI;
else if ( x > 1.0 && x < 1.000001 ) HARad = 0.0;
else if ( x < -1.0 ) {
kdWarning() << i18n( "Coordinate out of range." );
HARad = dms::PI;
} else if ( x > 1.0 ) {
kdWarning() << i18n( "Coordinate out of range." );
HARad = 0.0;
} else HARad = acos( x );
if ( sinAz > 0.0 ) HARad = 2.0*dms::PI - HARad; // resolve acos() ambiguity
RA.setRadians( LST->radians() - HARad );
RA.setD( RA.reduce().Degrees() ); // 0 <= RA < 24
}
void SkyPoint::findEcliptic( const dms *Obliquity, dms &EcLong, dms &EcLat ) {
double sinRA, cosRA, sinOb, cosOb, sinDec, cosDec, tanDec;
ra()->SinCos( sinRA, cosRA );
dec()->SinCos( sinDec, cosDec );
Obliquity->SinCos( sinOb, cosOb );
tanDec = sinDec/cosDec;
double y = sinRA*cosOb + tanDec*sinOb;
double ELongRad = atan( y/cosRA );
//resolve atan ambiguity
if ( cosRA < 0 ) ELongRad += dms::PI;
if ( cosRA > 0 && y < 0 ) ELongRad += 2.0*dms::PI;
EcLong.setRadians( ELongRad );
EcLat.setRadians( asin( sinDec*cosOb - cosDec*sinOb*sinRA ) );
}
void SkyPoint::setFromEcliptic( const dms *Obliquity, const dms *EcLong, const dms *EcLat ) {
double sinLong, cosLong, sinLat, cosLat, sinObliq, cosObliq;
EcLong->SinCos( sinLong, cosLong );
EcLat->SinCos( sinLat, cosLat );
Obliquity->SinCos( sinObliq, cosObliq );
double sinDec = sinLat*cosObliq + cosLat*sinObliq*sinLong;
double y = sinLong*cosObliq - (sinLat/cosLat)*sinObliq;
double RARad = atan( y / cosLong );
//resolve ambiguity of atan:
if ( cosLong < 0 ) RARad += dms::PI;
if ( cosLong > 0 && y < 0 ) RARad += 2.0*dms::PI;
//DMS_SPEED
//dms newRA, newDec;
//newRA.setRadians( RARad );
//newDec.setRadians( asin( sinDec ) );
RA.setRadians( RARad );
Dec.setRadians( asin(sinDec) );
}
void SkyPoint::precess( const KSNumbers *num) {
double cosRA0, sinRA0, cosDec0, sinDec0;
double v[3], s[3];
RA0.SinCos( sinRA0, cosRA0 );
Dec0.SinCos( sinDec0, cosDec0 );
s[0] = cosRA0*cosDec0;
s[1] = sinRA0*cosDec0;
s[2] = sinDec0;
//Multiply P2 and s to get v, the vector representing the new coords.
for ( unsigned int i=0; i<3; ++i ) {
v[i] = 0.0;
for (uint j=0; j< 3; ++j) {
v[i] += num->p2( j, i )*s[j];
}
}
//Extract RA, Dec from the vector:
RA.setRadians( atan( v[1]/v[0] ) );
Dec.setRadians( asin( v[2] ) );
//resolve ambiguity of atan()
if ( v[0] < 0.0 ) {
RA.setD( RA.Degrees() + 180.0 );
} else if( v[1] < 0.0 ) {
RA.setD( RA.Degrees() + 360.0 );
}
}
void SkyPoint::nutate(const KSNumbers *num) {
double cosRA, sinRA, cosDec, sinDec, tanDec;
dms dRA1, dRA2, dDec1, dDec2;
double cosOb, sinOb;
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
num->obliquity()->SinCos( sinOb, cosOb );
//Step 2: Nutation
if ( fabs( Dec.Degrees() ) < 80.0 ) { //approximate method
tanDec = sinDec/cosDec;
dRA1.setD( num->dEcLong()*( cosOb + sinOb*sinRA*tanDec ) - num->dObliq()*cosRA*tanDec );
dDec1.setD( num->dEcLong()*( sinOb*cosRA ) + num->dObliq()*sinRA );
RA.setD( RA.Degrees() + dRA1.Degrees() );
Dec.setD( Dec.Degrees() + dDec1.Degrees() );
} else { //exact method
dms EcLong, EcLat;
findEcliptic( num->obliquity(), EcLong, EcLat );
//Add dEcLong to the Ecliptic Longitude
dms newLong( EcLong.Degrees() + num->dEcLong() );
setFromEcliptic( num->obliquity(), &newLong, &EcLat );
}
}
void SkyPoint::aberrate(const KSNumbers *num) {
double cosRA, sinRA, cosDec, sinDec;
dms dRA2, dDec2;
double cosOb, sinOb, cosL, sinL, cosP, sinP;
double K = num->constAberr().Degrees(); //constant of aberration
double e = num->earthEccentricity();
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
num->obliquity()->SinCos( sinOb, cosOb );
double tanOb = sinOb/cosOb;
num->sunTrueLongitude().SinCos( sinL, cosL );
num->earthPerihelionLongitude().SinCos( sinP, cosP );
//Step 3: Aberration
dRA2.setD( -1.0 * K * ( cosRA * cosL * cosOb + sinRA * sinL )/cosDec
+ e * K * ( cosRA * cosP * cosOb + sinRA * sinP )/cosDec );
dDec2.setD( -1.0 * K * ( cosL * cosOb * ( tanOb * cosDec - sinRA * sinDec ) + cosRA * sinDec * sinL )
+ e * K * ( cosP * cosOb * ( tanOb * cosDec - sinRA * sinDec ) + cosRA * sinDec * sinP ) );
RA.setD( RA.Degrees() + dRA2.Degrees() );
Dec.setD( Dec.Degrees() + dDec2.Degrees() );
}
void SkyPoint::updateCoords( KSNumbers *num, bool /*includePlanets*/, const dms *lat, const dms *LST ) {
dms pRA, pDec;
//Correct the catalog coordinates for the time-dependent effects
//of precession, nutation and aberration
precess(num);
nutate(num);
aberrate(num);
if ( lat || LST )
kdWarning() << i18n( "lat and LST parameters should only be used in KSPlanetBase objects." ) << endl;
}
void SkyPoint::precessFromAnyEpoch(long double jd0, long double jdf){
double cosRA, sinRA, cosDec, sinDec;
double v[3], s[3];
RA.setD( RA0.Degrees() );
Dec.setD( Dec0.Degrees() );
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
if (jd0 == jdf)
return;
if ( jd0 == B1950) {
B1950ToJ2000();
jd0 = J2000;
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
}
if (jd0 !=jdf) {
// The original coordinate is referred to the FK5 system and
// is NOT J2000.
if ( jd0 != J2000 ) {
//v is a column vector representing input coordinates.
KSNumbers *num = new KSNumbers (jd0);
v[0] = cosRA*cosDec;
v[1] = sinRA*cosDec;
v[2] = sinDec;
//Need to first precess to J2000.0 coords
//s is the product of P1 and v; s represents the
//coordinates precessed to J2000
for ( unsigned int i=0; i<3; ++i ) {
s[i] = num->p1( 0, i )*v[0] +
num->p1( 1, i )*v[1] +
num->p1( 2, i )*v[2];
}
delete num;
//Input coords already in J2000, set s accordingly.
} else {
s[0] = cosRA*cosDec;
s[1] = sinRA*cosDec;
s[2] = sinDec;
}
if ( jdf == B1950) {
RA.setRadians( atan2( s[1],s[0] ) );
Dec.setRadians( asin( s[2] ) );
J2000ToB1950();
return;
}
KSNumbers *num = new KSNumbers (jdf);
for ( unsigned int i=0; i<3; ++i ) {
v[i] = num->p2( 0, i )*s[0] +
num->p2( 1, i )*s[1] +
num->p2( 2, i )*s[2];
}
delete num;
RA.setRadians( atan2( v[1],v[0] ) );
Dec.setRadians( asin( v[2] ) );
if (RA.Degrees() < 0.0 )
RA.setD( RA.Degrees() + 360.0 );
return;
}
}
/** No descriptions */
void SkyPoint::apparentCoord(long double jd0, long double jdf){
precessFromAnyEpoch(jd0,jdf);
KSNumbers *num = new KSNumbers (jdf);
nutate(num);
aberrate(num);
delete num;
}
void SkyPoint::Equatorial1950ToGalactic(dms &galLong, dms &galLat) {
double a = 192.25;
dms b, c;
double sinb, cosb, sina_RA, cosa_RA, sinDEC, cosDEC, tanDEC;
c.setD(303);
b.setD(27.4);
tanDEC = tan( Dec.radians() );
b.SinCos(sinb,cosb);
dms( a - RA.Degrees() ).SinCos(sina_RA,cosa_RA);
Dec.SinCos(sinDEC,cosDEC);
galLong.setRadians( c.radians() - atan2( sina_RA, cosa_RA*sinb-tanDEC*cosb) );
galLong = galLong.reduce();
galLat.setRadians( asin(sinDEC*sinb+cosDEC*cosb*cosa_RA) );
}
void SkyPoint::GalacticToEquatorial1950(const dms* galLong, const dms* galLat) {
double a = 123.0;
dms b, c, galLong_a;
double sinb, cosb, singLat, cosgLat, tangLat, singLong_a, cosgLong_a;
c.setD(12.25);
b.setD(27.4);
tangLat = tan( galLat->radians() );
galLat->SinCos(singLat,cosgLat);
dms( galLong->Degrees()-a ).SinCos(singLong_a,cosgLong_a);
b.SinCos(sinb,cosb);
RA.setRadians(c.radians() + atan2(singLong_a,cosgLong_a*sinb-tangLat*cosb) );
RA = RA.reduce();
// raHourCoord = dms( raCoord.Hours() );
Dec.setRadians( asin(singLat*sinb+cosgLat*cosb*cosgLong_a) );
}
void SkyPoint::B1950ToJ2000(void) {
double cosRA, sinRA, cosDec, sinDec;
// double cosRA0, sinRA0, cosDec0, sinDec0;
double v[3], s[3];
// 1984 January 1 0h
KSNumbers *num = new KSNumbers (2445700.5);
// Eterms due to aberration
addEterms();
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
// Precession from B1950 to J1984
s[0] = cosRA*cosDec;
s[1] = sinRA*cosDec;
s[2] = sinDec;
for ( unsigned int i=0; i<3; ++i ) {
v[i] = num->p2b( 0, i )*s[0] + num->p2b( 1, i )*s[1] +
num->p2b( 2, i )*s[2];
}
// RA zero-point correction at 1984 day 1, 0h.
RA.setRadians( atan2( v[1],v[0] ) );
Dec.setRadians( asin( v[2] ) );
RA.setH( RA.Hours() + 0.06390/3600. );
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
s[0] = cosRA*cosDec;
s[1] = sinRA*cosDec;
s[2] = sinDec;
// Precession from 1984 to J2000.
for ( unsigned int i=0; i<3; ++i ) {
v[i] = num->p1( 0, i )*s[0] +
num->p1( 1, i )*s[1] +
num->p1( 2, i )*s[2];
}
RA.setRadians( atan2( v[1],v[0] ) );
Dec.setRadians( asin( v[2] ) );
delete num;
}
void SkyPoint::J2000ToB1950(void) {
double cosRA, sinRA, cosDec, sinDec;
// double cosRA0, sinRA0, cosDec0, sinDec0;
double v[3], s[3];
// 1984 January 1 0h
KSNumbers *num = new KSNumbers (2445700.5);
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
s[0] = cosRA*cosDec;
s[1] = sinRA*cosDec;
s[2] = sinDec;
// Precession from J2000 to 1984 day, 0h.
for ( unsigned int i=0; i<3; ++i ) {
v[i] = num->p2( 0, i )*s[0] +
num->p2( 1, i )*s[1] +
num->p2( 2, i )*s[2];
}
RA.setRadians( atan2( v[1],v[0] ) );
Dec.setRadians( asin( v[2] ) );
// RA zero-point correction at 1984 day 1, 0h.
RA.setH( RA.Hours() - 0.06390/3600. );
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
// Precession from B1950 to J1984
s[0] = cosRA*cosDec;
s[1] = sinRA*cosDec;
s[2] = sinDec;
for ( unsigned int i=0; i<3; ++i ) {
v[i] = num->p1b( 0, i )*s[0] + num->p1b( 1, i )*s[1] +
num->p1b( 2, i )*s[2];
}
RA.setRadians( atan2( v[1],v[0] ) );
Dec.setRadians( asin( v[2] ) );
// Eterms due to aberration
subtractEterms();
delete num;
}
SkyPoint SkyPoint::Eterms(void) {
double sd, cd, sinEterm, cosEterm;
dms raTemp, raDelta, decDelta;
Dec.SinCos(sd,cd);
raTemp.setH( RA.Hours() + 11.25);
raTemp.SinCos(sinEterm,cosEterm);
raDelta.setH( 0.0227*sinEterm/(3600.*cd) );
decDelta.setD( 0.341*cosEterm*sd/3600. + 0.029*cd/3600. );
SkyPoint spDelta = SkyPoint (raDelta, decDelta);
return spDelta;
}
void SkyPoint::addEterms(void) {
SkyPoint spd = Eterms();
RA.setD( RA.Degrees() + spd.ra()->Degrees() );
Dec.setD( Dec.Degrees() + spd.dec()->Degrees() );
}
void SkyPoint::subtractEterms(void) {
SkyPoint spd = Eterms();
RA.setD( RA.Degrees() - spd.ra()->Degrees() );
Dec.setD( Dec.Degrees() - spd.dec()->Degrees() );
}
dms SkyPoint::angularDistanceTo(SkyPoint *sp) {
double dalpha = ra()->radians() - sp->ra()->radians() ;
double ddelta = dec()->radians() - sp->dec()->radians() ;
double sa = sin(dalpha/2.);
double sd = sin(ddelta/2.);
double hava = sa*sa;
double havd = sd*sd;
double aux = havd + cos (dec()->radians()) * cos(sp->dec()->radians())
* hava;
dms angDist;
angDist.setRadians( 2 * fabs(asin( sqrt(aux) )) );
return angDist;
}
TQString SkyPoint::constellation( TQPtrList<CSegment> &csegmentList, TQPtrList<SkyObject> &cnameList ) const {
//Identify the constellation that contains point p.
//First, find all CSegments that bracket the RA of p.
//Then, identify the pair of these bracketing segments which bracket p in the Dec direction.
//Each segment has two cnames, identifying the 2 constellations which the segment delineates.
//There will be a name in common between the pair, this is the constellation that p is in.
//
//Corner case 1: points near the celestial poles are not bracketed by csegments.
//Corner case 2: it is possible that *both* cnames are shared between the two segments.
//In this case, we have to do more work to decide which is truly correct.
TQPtrList<SkyPoint> p1List, p2List;
TQStringList name1List, name2List;
TQString abbrev("");
double pdc = dec()->Degrees();
double pra(0.0); //defined in the loop, because we may modify it there
for ( CSegment *seg = csegmentList.first(); seg; seg = csegmentList.next() ) {
SkyPoint *p1 = seg->firstNode();
for ( SkyPoint *p2 = seg->nextNode(); p2; p2 = seg->nextNode() ) {
pra = ra()->Degrees();
double p1ra = p1->ra()->Degrees();
double p2ra = p2->ra()->Degrees();
if ( p1ra > 330. && p2ra < 30. ) { //wrap RA coordinate, if necessary
p1ra -= 360.0;
if ( pra > 330. ) pra -= 360.;
}
if ( p2ra > 330. && p1ra < 30. ) { //wrap RA coordinate, if necessary
p2ra -= 360.0;
if ( pra > 330. ) pra -= 360.;
}
if ( p1ra <= pra && p2ra >= pra ) { //bracketing segment?
p1List.append( p1 );
p2List.append( p2 );
name1List.append( seg->name1() );
name2List.append( seg->name2() );
break;
} else if ( p2ra <= pra && p1ra >= pra ) { //bracketing segment? (RA order reversed)
p1List.append( p2 ); //make sure p1List gets the smaller bracketing RA
p2List.append( p1 );
name1List.append( seg->name1() );
name2List.append( seg->name2() );
break;
}
p1 = p2;
}
}
//Should not happen:
if ( p1List.count() == 0 ) {
kdWarning() << "A: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
//Normal case: more than one segment brackets in RA. Find segments which also bracket in Dec.
double dupper(90.), dlower(-90.);
int iupper(-1), ilower(-1);
for ( uint i=0; i < p1List.count(); ++i ) {
SkyPoint *p1 = p1List.at(i);
SkyPoint *p2 = p2List.at(i);
//Find Dec value along segment at RA of p:
double f = ( pra - p1->ra()->Degrees() ) / ( p2->ra()->Degrees() - p1->ra()->Degrees()); //fractional distance along segment
double segDec = f*p2->dec()->Degrees() + (1.0-f)*p1->dec()->Degrees();
if ( segDec >= pdc && segDec < dupper ) { dupper = segDec; iupper = i; }
if ( segDec <= pdc && segDec > dlower ) { dlower = segDec; ilower = i; }
}
//Corner case 1: Points near one of the poles are not bracketed by segments in the Dec direction.
//In this case, either iupper or ilower will remain at its preassigned invalid value (-1)
//Identify the constellation by extrapolating away from the pole to the next segment.
//This will identify which of the two names is the neighboring constellation
//so our target constell. is the other one.
//(note that we can't just assume Ursa Minor or Octans, because of precession: these constellations
//are not near the pole at all epochs
if ( iupper == -1 ) { //point near north pole
int ilow2(-1);
double dlow2(-90.);
for ( uint i=0; i < p1List.count(); ++i ) {
if ( i != ilower ) {
SkyPoint *p1 = p1List.at(i);
SkyPoint *p2 = p2List.at(i);
//Find Dec value along segment at RA of p:
double f = ( pra - p1->ra()->Degrees() ) / ( p2->ra()->Degrees() - p1->ra()->Degrees()); //fractional distance along segment
double segDec = f*p2->dec()->Degrees() + (1.0-f)*p1->dec()->Degrees();
if ( segDec > dlow2 && segDec < dlower ) { dlow2 = segDec; ilow2 = i; }
}
}
if ( ilow2 == -1 ) { //whoops, what happened?
kdWarning() << "B: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
//If name1(ilower) is the adjacent constellation, then name2(ilower) must be the answer
if ( name1List[ ilower ] == name1List[ ilow2 ] || name1List[ ilower ] == name2List[ ilow2 ] )
abbrev = name2List[ ilower ];
//If name2(ilower) is the adjacent constellation, then name1(ilower) must be the answer
else if ( name2List[ ilower ] == name1List[ ilow2 ] || name2List[ ilower ] == name2List[ ilow2 ] )
abbrev = name1List[ ilower ];
else { //doh!
kdWarning() << "C: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
} else if ( ilower == -1 ) { //point near south pole
int iup2(-1);
double dup2(90.);
for ( uint i=0; i < p1List.count(); ++i ) {
if ( i != iupper ) {
SkyPoint *p1 = p1List.at(i);
SkyPoint *p2 = p2List.at(i);
//Find Dec value along segment at RA of p:
double f = ( pra - p1->ra()->Degrees() ) / ( p2->ra()->Degrees() - p1->ra()->Degrees()); //fractional distance along segment
double segDec = f*p2->dec()->Degrees() + (1.0-f)*p1->dec()->Degrees();
if ( segDec < dup2 && segDec > dupper ) { dup2 = segDec; iup2 = i; }
}
}
if ( iup2 == -1 ) { //whoops, what happened?
kdWarning() << "D: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
//If name1(iupper) is the adjacent constellation, then name2(iupper) must be the answer
if ( name1List[ iupper ] == name1List[ iup2 ] || name1List[ iupper ] == name2List[ iup2 ] )
abbrev = name2List[ iupper ] ;
//If name2(iupper) is the adjacent constellation, then name1(iupper) must be the answer
else if ( name2List[ iupper ] == name1List[ iup2 ] || name2List[ iupper ] == name2List[ iup2 ] )
abbrev = name1List[ iupper ];
else { //doh!
kdWarning() << "E: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
}
//Corner case 2: Both name1 and name2 are in common in the bracketing segments
//This can happen if a constellation is both above and below the true bracketing constellation
//Resolve it by again extending up or down to the next segment, which will share one of the ambiguous
//names. The answer is the one not shared in this next segment.
//To ensure that there will be a next segment, go up if dec is negative, otherwise go down.
else if ( (name1List[ iupper ] == name1List[ ilower ] || name1List[ iupper ] == name2List[ ilower ])
&& (name2List[ iupper ] == name1List[ ilower ] || name2List[ iupper ] == name2List[ ilower ]) ) {
if ( pdc < 0.0 ) { //find next segment up
int iup2(0);
double dup2(90.0);
for ( uint i=0; i < p1List.count(); ++i ) {
if ( i != iupper ) {
SkyPoint *p1 = p1List.at(i);
SkyPoint *p2 = p2List.at(i);
//Find Dec value along segment at RA of p:
double f = ( pra - p1->ra()->Degrees() ) / ( p2->ra()->Degrees() - p1->ra()->Degrees()); //fractional distance along segment
double segDec = f*p2->dec()->Degrees() + (1.0-f)*p1->dec()->Degrees();
if ( segDec < dup2 && segDec > dupper ) { dup2 = segDec; iup2 = i; }
}
}
//If name1(iupper) is the adjacent constellation, then name2(iupper) must be the answer
if ( name1List[ iupper ] == name1List[ iup2 ] || name1List[ iupper ] == name2List[ iup2 ] )
abbrev = name2List[ iupper ];
//If name2(iupper) is the adjacent constellation, then name1(iupper) must be the answer
else if ( name2List[ iupper ] == name1List[ iup2 ] || name2List[ iupper ] == name2List[ iup2 ] )
abbrev = name1List[ iupper ];
else { //doh!
kdWarning() << "F: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
} else { //pdc > 0.0, so search down
int ilow2(-1);
double dlow2(-90.);
for ( uint i=0; i < p1List.count(); ++i ) {
if ( i != ilower ) {
SkyPoint *p1 = p1List.at(i);
SkyPoint *p2 = p2List.at(i);
//Find Dec value along segment at RA of p:
double f = ( pra - p1->ra()->Degrees() ) / ( p2->ra()->Degrees() - p1->ra()->Degrees()); //fractional distance along segment
double segDec = f*p2->dec()->Degrees() + (1.0-f)*p1->dec()->Degrees();
if ( segDec > dlow2 && segDec < dlower ) { dlow2 = segDec; ilow2 = i; }
}
}
if ( ilow2 == -1 ) { //whoops, what happened?
kdWarning() << "G: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
//If name1(ilower) is the adjacent constellation, then name2(ilower) must be the answer
if ( name1List[ ilower ] == name1List[ ilow2 ] || name1List[ ilower ] == name2List[ ilow2 ] )
abbrev = name2List[ ilower ];
//If name2(ilower) is the adjacent constellation, then name1(ilower) must be the answer
else if ( name2List[ ilower ] == name1List[ ilow2 ] || name2List[ ilower ] == name2List[ ilow2 ] )
abbrev = name1List[ ilower ];
else { //doh!
kdWarning() << "H: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
}
}
//Normal case: one of the pair of names (name1/name2) should be shared between
//the two bracketing segments
else if ( name1List[ iupper ] == name1List[ ilower ] || name1List[ iupper ] == name2List[ ilower ] )
abbrev = name1List[ iupper ];
else if ( name2List[ iupper ] == name1List[ ilower ] || name2List[ iupper ] == name2List[ ilower ] )
abbrev = name2List[ iupper ];
//If we reach here, then neither name1 nor name2 were shared between the bracketing segments!
else {
kdWarning() << "I: " << i18n("No constellation found for point: (%1, %2)").tqarg(ra()->toHMSString()).tqarg(dec()->toDMSString()) << endl;
return i18n("Unknown");
}
//Finally, match the abbreviated name to the full constellation name, and return that name
for ( SkyObject *o = cnameList.first(); o; o = cnameList.next() ) {
if ( abbrev.lower() == o->name2().lower() ) {
TQString r = i18n( "Constellation name (optional)", o->name().local8Bit().data() );
r = r.left(1) + r.mid(1).lower(); //lowercase letters (except first letter)
int i = r.tqfind(" ");
i++;
if ( i>0 ) r = r.left(i) + r.mid(i,1).upper() + r.mid(i+1); //capitalize 2nd word
return r;
}
}
return i18n("Unknown");
}
double SkyPoint::vRSun(long double jd0) {
dms asun,dsun;
double ca, sa, cd, sd, vsun;
double cosRA, sinRA, cosDec, sinDec;
/* Sun apex (where the sun goes) coordinates */
asun.setD(270.9592); // Right ascention: 18h 3m 50.2s [J2000]
dsun.setD(30.00467); // Declination: 30^o 0' 16.8'' [J2000]
vsun=20.; // [km/s]
asun.SinCos(sa,ca);
dsun.SinCos(sd,cd);
/* We need an auxiliary SkyPoint since we need the
* source referred to the J2000 equinox and we do not want to ovewrite
* the current values
*/
SkyPoint aux;
aux.set(RA0,Dec0);
aux.precessFromAnyEpoch(jd0, J2000);
aux.ra()->SinCos( sinRA, cosRA );
aux.dec()->SinCos( sinDec, cosDec );
/* Computation is done performing the scalar product of a unitary vector
in the direction of the source with the vector velocity of Sun, both being in the
LSR reference system:
Vlsr = Vhel + Vsun.u_radial =>
Vlsr = Vhel + vsun(cos D cos A,cos D sen A,sen D).(cos d cos a,cos d sen a,sen d)
Vhel = Vlsr - Vsun.u_radial
*/
return vsun *(cd*cosDec*(cosRA*ca + sa*sinRA) + sd*sinDec);
}
double SkyPoint::vHeliocentric(double vlsr, long double jd0) {
return vlsr - vRSun(jd0);
}
double SkyPoint::vHelioToVlsr(double vhelio, long double jd0) {
return vhelio + vRSun(jd0);
}
double SkyPoint::vREarth(long double jd0)
{
double sinRA, sinDec, cosRA, cosDec, vREarth;
/* u_radial = unitary vector in the direction of the source
Vlsr = Vhel + Vsun.u_radial
= Vgeo + VEarth.u_radial + Vsun.u_radial =>
Vgeo = (Vlsr -Vsun.u_radial) - VEarth.u_radial
= Vhel - VEarth.u_radial
= Vhel - (vx, vy, vz).(cos d cos a,cos d sen a,sen d)
*/
/* We need an auxiliary SkyPoint since we need the
* source referred to the J2000 equinox and we do not want to ovewrite
* the current values
*/
SkyPoint aux;
aux.set(RA0,Dec0);
aux.precessFromAnyEpoch(jd0, J2000);
aux.ra()->SinCos( sinRA, cosRA );
aux.dec()->SinCos( sinDec, cosDec );
/* vEarth is referred to the J2000 equinox, hence we need that
the source coordinates are also in the same reference system.
*/
KSNumbers *num = new KSNumbers(jd0);
vREarth = num->vEarth(0) * cosDec * cosRA +
num->vEarth(1) * cosDec * sinRA +
num->vEarth(2) * sinDec;
return vREarth;
}
double SkyPoint::vGeocentric(double vhelio, long double jd0)
{
return vhelio - vREarth(jd0);
}
double SkyPoint::vGeoToVHelio(double vgeo, long double jd0)
{
return vgeo + vREarth(jd0);
}
double SkyPoint::vRSite(double vsite[3])
{
double sinRA, sinDec, cosRA, cosDec, vREarth;
RA.SinCos( sinRA, cosRA );
Dec.SinCos( sinDec, cosDec );
return vsite[0]*cosDec*cosRA + vsite[1]*cosDec*sinRA + vsite[2]*sinDec;
}
double SkyPoint::vTopoToVGeo(double vtopo, double vsite[3])
{
return vtopo + vRSite(vsite);
}
double SkyPoint::vTopocentric(double vgeo, double vsite[3])
{
return vgeo - vRSite(vsite);
}
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