XY-plane: | Solar equator of date |
+X-axis: | ascending node on 1854 Jan 1, noon (JD 239 8220.0) |
Angles: | Heliographic latitude and longitude right handed. |
Transform: | |
with the values from eqn.13 and [S. Table 15.7]. |
Alternatively (but less exact) one may use the transformation from ecliptic coordinates:
Transform:
where
and are defined in eqn.14
and the prime meridian angle is given by
(16) |
XY-plane: | Earth mean ecliptic of date. |
+X-axis: | vector (Sun-Earth). |
Transform: |
where is the geometric ecliptic longitude of the Earth which can be determined by one of the methods described in section 4.2.1 or directly from eqn.36 to a precision of .
XY-plane: | Solar equator of date. |
+X-axis: | Intersection between solar equator and solar central meridian of date. |
Angles: | Heliocentric latitude and central longitude (increasing eastward) right handed. |
Transform: | , where is defined in eqn.17. |
XY-plane: | Solar equator of J2000.0. |
+X-axis: | Solar ascending node on ecliptic of J2000.0. |
Transform: |
XY-plane: | Solar equator of date. |
+X-axis: | Solar ascending node on ecliptic of date. |
Transform: |