PROJ/docs/source/operations/projections, branch 7.2

Fix configuration for sphinxcontrib-bibtex version 2 or later (#2572)

2021-03-11T10:29:35+00:00

Update isea.rst

2020-12-02T17:23:28+00:00

Clarifying defaults for ISEA.

Update utm.rst

2020-11-20T15:43:40+00:00

Typo

Add +proj=col_urban projection, implementing a EPSG projection method used by a number of projected CRS in Colombia (fixes #589)

2020-10-25T20:17:29+00:00

Fix typos spotted by scripts/fix_typos.sh

2020-10-25T15:18:58+00:00

Minor fixes to tmerc documentation

2020-10-23T19:32:35+00:00

merc.rst: change "origins from 15th cent" to 16th cent.

2020-10-23T12:20:17+00:00

merc.rst: revert to ln instead of log.

2020-10-22T17:53:45+00:00

Also define merc (resp. tmerc) as the conformal projection in which the
equator (resp. a chosen meridan} projects to a straight line at constant
scale.

Flesh out the documentation for Mercator

2020-10-22T15:01:29+00:00

This addresses item 1 in issue #2387

Things to note:

* I made "editorial" changes to the text.  The virtues and vices of
  Mercator are a hot topic.  So check these out.  (I judged that the
  text I replaced to be pretty misleading.)

* I include the radius of the sphere/ellipsoid in the formulas (and I
  did this also for my mods for tmerc documentation).  Surely this is
  better than leaving the reader to figure out how this is introduced.

* I include the "old-style" (ca 18th century) formulas and the newer
  ones in terms of hyperbolic functions.  The former may be the familiar
  ones, but the latter are better for computation (more succinct, more
  accurate, faster, preserve parity).

* For the inverse ellipsoidal transformation, I just say that the
  formula for psi is inverted iteratively.  This is probably sufficient,
  but it could be expanded later.

Document the default poder_engsager algorithm for tmerc. (#2379)

2020-10-18T21:36:24+00:00

* Document the default poder_engsager algorithm for tmerc.

* Give exact expression for phi' in terms of phi

* Aadd another datapoint on range of applicability + explanation for
complex numbers.

* Update tmerc figure with one reflecting poder/engsager algo.

Courtesy of @hobu.

Co-authored-by: Charles Karney