Changeset 3111 in Sophya for trunk/SophyaExt/XephemAstroLib/aberration.c

Timestamp:

Nov 22, 2006, 2:53:31 PM (19 years ago)

Author:

cmv

Message:

mise en conformite xephem 3.7.2 cmv 22/11/2006

File:

• trunk/SophyaExt/XephemAstroLib/aberration.c (modified) (3 diffs)

trunk/SophyaExt/XephemAstroLib/aberration.c

@@ -35 +35 @@
 ab_eq (double mj, double lsn, double *ra, double *dec)
 {
+#if defined(USE_MEEUS_AB_EQ)
+
+        /* this claims to account for earth orbit excentricity and is also
+         * smooth clear to dec=90 but it does not work well backwards with
+         * ap_as()
+         */
         ab_aux(mj, ra, dec, lsn, AB_EQ_EOD);
+
+#else /* use Montenbruck */
+
+        /* this agrees with Meeus to within 0.2 arcsec until dec gets larger
+         * than about 89.9, then grows to 1as at 89.97. but it works very
+         * smoothly with ap_as
+         */
+        double x, y, z;         /* equatorial rectangular coords */
+        double vx, vy, vz;      /* aberration velocity in rectangular coords */
+        double L;               /* helio long of earth */
+        double cL;
+        double r;
+
+
+        sphcart (*ra, *dec, 1.0, &x, &y, &z);
+
+        L = 2*PI*(0.27908 + 100.00214*(mj-J2000)/36525.0);
+        cL = cos(L);
+        vx = -0.994e-4*sin(L);
+        vy = 0.912e-4*cL;
+        vz = 0.395e-4*cL;
+        x += vx;
+        y += vy;
+        z += vz;
+
+        cartsph (x, y, z, ra, dec, &r);
+
+#endif
 }
 
@@ -111 +145 @@
                 
                 *ra += dra;
-                range (ra, 2*PI);
                 *dec += ddec;
+                radecrange (ra, dec);
             }
             break;
@@ -125 +159 @@
 
 /* For RCS Only -- Do Not Edit */
-static char *rcsid[2] = {(char *)rcsid, "@(#) $RCSfile: aberration.c,v $ $Date: 2005-08-21 10:02:36 $ $Revision: 1.5 $ $Name: not supported by cvs2svn $"};
+static char *rcsid[2] = {(char *)rcsid, "@(#) $RCSfile: aberration.c,v $ $Date: 2006-11-22 13:53:27 $ $Revision: 1.6 $ $Name: not supported by cvs2svn $"};