Why are coordinate transformations so confusing?
summary
Explains why coordinate shifts matter: New Zealand uses an ITRF-based datum plus a deformation model that tracks plate velocities and earthquake displacements, producing 124 grids (CSV ZIP + Python tool) to convert between NZGD2000 and global frames; earthquakes like Christchurch force rapid patch releases and ongoing updates; near-real-time change detection comes from differential interferometric SAR showing ~5 cm per cycle, and modern standards/OGC support plus PROJ now automate time-aware, multi-step transformations.
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chapters (12)
- 0:00Introduction and purpose
- 1:32Why coordinate transformations are confusing
- 3:21Basics of coordinates and their issues
- 5:48Global vs local reference systems
- 7:34Movement of the Earth's crust
- 9:42Deformation models explained
- 12:13Earthquakes and coordinate shifts
- 14:41Measuring deformation with radar
- 16:27Creating a dynamic datum
- 18:38Using deformation models in practice
- 20:42Standards and open source solutions
- 23:34Summary and takeaways
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