[SIS-260] Geographic 3D to 2D conversions (EPSG:9659)

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.7
• Component/s: Referencing
• Assignee: Martin Desruisseaux
• Reporter: Martin Desruisseaux
• Created: 22/Jul/15 09:25
• Updated: 17/Nov/17 14:21
• Resolved: 10/Nov/15 21:36

Description

The forward case (3D to 2D) is trivial: just drop the height. The reverse conversion however is in principle undefined, but in practice often needed. The "less bad" approach would be to take a mean-sea level of 0, which is uneasy to convert to ellipsoidal height. See §2.2.4 in IOGP Publication 373-7-2 – Geomatics Guidance Note number 7, part 2 – April 2015.