[SIS-302] Implement the spherical case of EllipsoidToCentric

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.7
• Component/s: Referencing
• Assignee: Martin Desruisseaux
• Reporter: Martin Desruisseaux
• Created: 12/Nov/15 14:14
• Updated: 15/Mar/16 13:07

Description

The "Ellipsoid to (geo)centric" transform currently target only Cartesian coordinate system. It should be easy to make it target spherical coordinate system too, since it is basically a matter of not performing the last calls to sin(λ) and sin(λ), and compute an arc-tangent for φ. More specifically we need to:

• Add a SPHERICAL enum value to EllipsoidToCentric.TargetType.
• Add a boolean field in EllipsoidToCentric for storing the target CS type in an efficient way.
• Take the above-cited field in account in the following formulas:
  • transform (forward conversion).
  • inverseTransform (inverse conversion).
  • transform : Matrix (derivative computation).

We could also opportunistically implement the cylindrical case, but its interest is not obvious.

Issue Links

• is part of: SIS-212 Coordinate operation methods to implement