[PROJ] Geodesic buffers/offsets?

[Nyall Dawson]

On Wed, 5 May 2021 at 10:43, Greg Troxel <gdt at lexort.com> wrote:
>

> > - for point datasets, create a custom projection centered over each
> > individual point and densify/transform the planimetric buffer in that
> > projection back to the geographic CRS
>
> This evokes some notion of close enough granularity, perhaps 100 points
> around a circle but with each of them being right.  But once you do
> that, I don't see how this differs from computing
>   DIRECT(PT1, distance, az_i) for az_i in (0..99)/100 * \pi.
> (I probably  got that wrong, but the  astute reader can consider what I
> should have said.)

Very good point -- the point case is quite trivial and would be well
addressed with your suggestion!

> Is the use case for this a situation where a local projection doesn't
> work because the area is so big?

Exactly -- the classic example is the "missile range" problem well
described in this article:
https://www.esri.com/news/arcuser/0111/geodesic.html

Nyall