| Term: | HCC |
| Definition: |
Heliocentric Cartesian - A 3-D orthonormalcoordinate system that is primarily intended to specify with two dimensionsa point on the solar disk. The Z axis points toward the observer. The Y axislies in the plane defined by the solar spin vector and the Z axis, positivenorthward. The X axis is perpendicular to the Y and Z axes, positive towardsolar west. Standard representation for this system is via the point's x andy values, expressed either as physical distances or as fractions of thesolar disk radius. |