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Merged in Durk's changes ...

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This commit is contained in:
curt
1997-12-30 16:36:40 +00:00
parent de235cc8be
commit 5c5e4fff7b
5 changed files with 189 additions and 88 deletions
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Scenery/moon.c
+94 -63
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@@ -28,6 +28,7 @@
#include "orbits.h"
#include "moon.h"
#include "../Aircraft/aircraft.h"
#include "../Include/general.h"
#include "../Main/views.h"
#include "../Time/fg_time.h"
@@ -148,80 +149,110 @@ struct CelestialCoord fgCalculateMoon(struct OrbElements params,
struct OrbElements sunParams,
struct fgTIME t)
{
struct CelestialCoord
result;
double
eccAnom, ecl, lonecl, latecl, actTime,
xv, yv, v, r, xh, yh, zh, xg, yg, zg, xe, ye, ze,
Ls, Lm, D, F;
struct CelestialCoord
geocCoord, topocCoord;
double
eccAnom, ecl, lonecl, latecl, actTime,
xv, yv, v, r, xh, yh, zh, xg, yg, zg, xe, ye, ze,
Ls, Lm, D, F, mpar, gclat, rho, HA, g;
struct fgAIRCRAFT *a;
struct fgFLIGHT *f;
/* calculate the angle between ecliptic and equatorial coordinate system */
actTime = fgCalcActTime(t);
ecl = fgDegToRad(23.4393 - 3.563E-7 * actTime); // in radians of course
a = &current_aircraft;
f = &a->flight;
/* calculate the angle between ecliptic and equatorial coordinate system */
actTime = fgCalcActTime(t);
ecl = fgDegToRad(23.4393 - 3.563E-7 * actTime); // in radians of course
/* calculate the eccentric anomaly */
eccAnom = fgCalcEccAnom(params.M, params.e);
/* calculate the eccentric anomaly */
eccAnom = fgCalcEccAnom(params.M, params.e);
/* calculate the moon's distance (d) and true anomaly (v) */
xv = params.a * ( cos(eccAnom) - params.e);
yv = params.a * ( sqrt(1.0 - params.e*params.e) * sin(eccAnom));
v =atan2(yv, xv);
r = sqrt(xv*xv + yv*yv);
/* estimate the geocentric rectangular coordinates here */
xh = r * (cos(params.N) * cos(v + params.w) - sin(params.N) * sin(v + params.w) * cos(params.i));
yh = r * (sin(params.N) * cos(v + params.w) + cos(params.N) * sin(v + params.w) * cos(params.i));
zh = r * (sin(v + params.w) * sin(params.i));
/* calculate the ecliptic latitude and longitude here */
lonecl = atan2( yh, xh);
latecl = atan2( zh, sqrt( xh*xh + yh*yh));
/* calculate the moon's distance (d) and true anomaly (v) */
xv = params.a * ( cos(eccAnom) - params.e);
yv = params.a * ( sqrt(1.0 - params.e*params.e) * sin(eccAnom));
v =atan2(yv, xv);
r = sqrt(xv*xv + yv*yv);
/* calculate a number of perturbations */
Ls = sunParams.M + sunParams.w;
Lm = params.M + params.w + params.N;
D = Lm - Ls;
F = Lm - params.N;
lonecl += fgDegToRad(
- 1.274 * sin (params.M - 2*D) // the Evection
+ 0.658 * sin (2 * D) // the Variation
- 0.186 * sin (sunParams.M) // the yearly variation
- 0.059 * sin (2*params.M - 2*D)
- 0.057 * sin (params.M - 2*D + sunParams.M)
+ 0.053 * sin (params.M + 2*D)
+ 0.046 * sin (2*D - sunParams.M)
+ 0.041 * sin (params.M - sunParams.M)
- 0.035 * sin (D) // the Parallactic Equation
- 0.031 * sin (params.M + sunParams.M)
- 0.015 * sin (2*F - 2*D)
+ 0.011 * sin (params.M - 4*D)
); /* Pheeuuwwww */
latecl += fgDegToRad(
- 0.173 * sin (F - 2*D)
- 0.055 * sin (params.M - F - 2*D)
- 0.046 * sin (params.M + F - 2*D)
+ 0.033 * sin (F + 2*D)
+ 0.017 * sin (2 * params.M + F)
); /* Yep */
/* estimate the geocentric rectangular coordinates here */
xh = r * (cos(params.N) * cos(v + params.w) - sin(params.N) * sin(v + params.w) * cos(params.i));
yh = r * (sin(params.N) * cos(v + params.w) + cos(params.N) * sin(v + params.w) * cos(params.i));
zh = r * (sin(v + params.w) * sin(params.i));
r += (
- 0.58 * cos(params.M - 2*D)
- 0.46 * cos(2*D)
); /* Ok! */
/* calculate the ecliptic latitude and longitude here */
lonecl = atan2( yh, xh);
latecl = atan2( zh, sqrt( xh*xh + yh*yh));
xg = r * cos(lonecl) * cos(latecl);
yg = r * sin(lonecl) * cos(latecl);
zg = r * sin(latecl);
/* calculate a number of perturbations */
Ls = sunParams.M + sunParams.w;
Lm = params.M + params.w + params.N;
D = Lm - Ls;
F = Lm - params.N;
xe = xg;
ye = yg * cos(ecl) - zg * sin(ecl);
ze = yg * sin(ecl) + zg * cos(ecl);
lonecl += fgDegToRad(
- 1.274 * sin (params.M - 2*D) // the Evection
+ 0.658 * sin (2 * D) // the Variation
- 0.186 * sin (sunParams.M) // the yearly variation
- 0.059 * sin (2*params.M - 2*D)
- 0.057 * sin (params.M - 2*D + sunParams.M)
+ 0.053 * sin (params.M + 2*D)
+ 0.046 * sin (2*D - sunParams.M)
+ 0.041 * sin (params.M - sunParams.M)
- 0.035 * sin (D) // the Parallactic Equation
- 0.031 * sin (params.M + sunParams.M)
- 0.015 * sin (2*F - 2*D)
+ 0.011 * sin (params.M - 4*D)
); /* Pheeuuwwww */
latecl += fgDegToRad(
- 0.173 * sin (F - 2*D)
- 0.055 * sin (params.M - F - 2*D)
- 0.046 * sin (params.M + F - 2*D)
+ 0.033 * sin (F + 2*D)
+ 0.017 * sin (2 * params.M + F)
); /* Yep */
r += (
- 0.58 * cos(params.M - 2*D)
- 0.46 * cos(2*D)
); /* Ok! */
geocCoord.RightAscension = atan2(ye, xe);
geocCoord.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
/* New since 25 december 1997 */
/* Calculate the moon's topocentric position instead of it's geocentric! */
xg = r * cos(lonecl) * cos(latecl);
yg = r * sin(lonecl) * cos(latecl);
zg = r * sin(latecl);
mpar = asin( 1 / r); /* calculate the moon's parrallax, i.e. the apparent size of the
(equatorial) radius of the Earth, as seen from the moon */
gclat = FG_Latitude - 0.083358 * sin (2 * fgDegToRad( FG_Latitude));
rho = 0.99883 + 0.00167 * cos(2 * fgDegToRad(FG_Latitude));
xe = xg;
ye = yg * cos(ecl) - zg * sin(ecl);
ze = yg * sin(ecl) + zg * cos(ecl);
if (geocCoord.RightAscension < 0)
geocCoord.RightAscension += (2*M_PI);
result.RightAscension = atan2(ye, xe);
result.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
return result;
HA = t.lst - (3.8197186 * geocCoord.RightAscension);
g = atan (tan(gclat) / cos( (HA / 3.8197186)));
topocCoord.RightAscension = geocCoord.RightAscension - mpar * rho * cos(gclat) * sin(HA) / cos(geocCoord.Declination);
topocCoord.Declination = geocCoord.Declination - mpar * rho * sin(gclat) * sin(g - geocCoord.Declination) / sin(g);
return topocCoord;
}