Restructure coordinate operations docs

4 files changed, 3 insertions, 178 deletions

diff --git a/docs/source/usage/operations/transformations/axisswap.rst b/docs/source/usage/operations/transformations/axisswap.rst
deleted file mode 100644
index ddaad075..00000000
--- a/docs/source/usage/operations/transformations/axisswap.rst
+++ /dev/null
@@ -1,39 +0,0 @@
-.. _axisswap:
-
-================================================================================
-Axis swap
-================================================================================
-
-Change the order and sign of 2,3 or 4 axes.
-
-+--------------+---------------------------------------------------------------+
-| **Options**                                                                  |
-+--------------+---------------------------------------------------------------+
-| `+order`     | Ordered comma-separated list of axis, e.g. `+order=2,1,3,4`   |
-+--------------+---------------------------------------------------------------+
-
-
-Each of the possible four axes are numbered with 1-4, such that the first input axis
-is 1, the second is 2 and so on. The output ordering is controlled by a list of the
-input axes re-ordered to the new mapping.
-
-Examples
-################################################################################
-
-Reversing the order of the axes::
-
-    +proj=axisswap +order=4,3,2,1
-
-Swapping the first two axes (x and y)::
-
-    +proj=axisswap +order=2,1,3,4
-
-The direction, or sign, of an axis can be changed by adding a minus in
-front of the axis-number::
-
-    +proj=axisswap +order=1,-2,3,4
-
-It is only necessary to specify the axes that are affected by the swap
-operation::
-
-    +proj=axisswap +order=2,1
diff --git a/docs/source/usage/operations/transformations/cart.rst b/docs/source/usage/operations/transformations/cart.rst
deleted file mode 100644
index 0c3c7c23..00000000
--- a/docs/source/usage/operations/transformations/cart.rst
+++ /dev/null
@@ -1,24 +0,0 @@
-.. _cart:
-
-================================================================================
-Cartesian to geodetic conversion
-================================================================================
-
-Convert geodetic coordinates to cartesian coordinates.
-
-+--------------+--------------------------------------------------------------------+
-| **Options**                                                                       |
-+--------------+--------------------------------------------------------------------+
-| `+ellps`     |  Ellipsoid of the input coordinates. If used together with the     |
-|              |  ellipsoid parameters below, ``+ellps`` is overwritten.            |
-+--------------+--------------------------------------------------------------------+
-| `+a`         | Semi-major radius of ellipsoid axis.                               |
-+--------------+--------------------------------------------------------------------+
-| `+b`         | Semi-minor radius of ellipsoid axis.                               |
-+--------------+--------------------------------------------------------------------+
-| `+es`        | Eccentricity of ellipsoid.                                         |
-+--------------+--------------------------------------------------------------------+
-| `+f`         | Flattening of ellipsoid.                                           |
-+--------------+--------------------------------------------------------------------+
-
-
diff --git a/docs/source/usage/operations/transformations/index.rst b/docs/source/usage/operations/transformations/index.rst
index 2966ed0d..112d9220 100644
--- a/docs/source/usage/operations/transformations/index.rst
+++ b/docs/source/usage/operations/transformations/index.rst
@@ -4,13 +4,13 @@
 Transformations
 ================================================================================
 
+Transformations coordinate operation in which the two coordinate reference
+systems are based on different datums.
+
 .. toctree::
    :maxdepth: 1
 
-   axisswap
-   cart
    helmert
    molodensky
    hgridshift
    vgridshift
-   unitconvert
diff --git a/docs/source/usage/operations/transformations/unitconvert.rst b/docs/source/usage/operations/transformations/unitconvert.rst
deleted file mode 100644
index ad848207..00000000
--- a/docs/source/usage/operations/transformations/unitconvert.rst
+++ /dev/null
@@ -1,112 +0,0 @@
-.. _unitconvert:
-
-================================================================================
-Unit conversion
-================================================================================
-
-Convert between various distance and time units.
-
-+--------------+--------------------------------------------------------------------+
-| **Options**                                                                       |
-+--------------+--------------------------------------------------------------------+
-| `+xy_in`     | Input unit of the horizontal components.                           |
-+--------------+--------------------------------------------------------------------+
-| `+xy_out`    | Output unit of the horizontal components.                          |
-+--------------+--------------------------------------------------------------------+
-| `+z_in`      | Input unit of the vertical component.                              |
-+--------------+--------------------------------------------------------------------+
-| `+z_out`     | Output unit of the vertical component.                             |
-+--------------+--------------------------------------------------------------------+
-| `+t_in`      | Input unit of the time component.                                  |
-+--------------+--------------------------------------------------------------------+
-| `+t_out`     | Output unit of the time component.                                 |
-+--------------+--------------------------------------------------------------------+
-
-There are many examples of coordinate reference systems that are expressed in
-other units than the meter. There are also many cases where temporal data
-has to be translated to different units. The `unitconvert` operation takes care
-of that.
-
-Many North American systems are defined with coordinates in feet. For example
-in Vermont::
-
-    +proj=pipeline
-    +step +proj=tmerc +lat_0=42.5 +lon_0=-72.5 +k=0.999964286 +x_0=500000.00001016 +y_0=0
-    +step +proj=unitconvert +xy_in=m +xy_out=us-ft
-
-Often when working with GNNS data the timestamps are presented in GPS-weeks,
-but when the data transformed with the `helmert` operation timestamps are
-expected to be in units of decimalyears. This can be fixed with `unitconvert`::
-
-    +proj=pipeline
-    +step +proj=unitconvert +t_in=gpsweek +t_out=decimalyear
-    +step +proj=helmert +epoch=2000.0 +t_obs=2017.5 ...
-
-
-Distance units
-###############################################################################
-
-In the table below all distance units supported by PROJ.4 is listed.
-The same list can also be produced on the command line with `proj` or `cs2cs`,
-by adding the `-lu` flag when calling the utility.
-
-+----------+---------------------------------+
-| Label    | Name                            |
-+----------+---------------------------------+
-|     km   | Kilometer                       |
-+----------+---------------------------------+
-|      m   | Meter                           |
-+----------+---------------------------------+
-|     dm   | Decimeter                       |
-+----------+---------------------------------+
-|     cm   | Centimeter                      |
-+----------+---------------------------------+
-|     mm   | Millimeter                      |
-+----------+---------------------------------+
-|    kmi   | International Nautical Mile     |
-+----------+---------------------------------+
-|     in   | International Inch              |
-+----------+---------------------------------+
-|     ft   | International Foot              |
-+----------+---------------------------------+
-|     yd   | International Yard              |
-+----------+---------------------------------+
-|     mi   | International Statute Mile      |
-+----------+---------------------------------+
-|   fath   | International Fathom            |
-+----------+---------------------------------+
-|     ch   | International Chain             |
-+----------+---------------------------------+
-|   link   | International Link              |
-+----------+---------------------------------+
-|  us-in   | U.S. Surveyor's Inch            |
-+----------+---------------------------------+
-|  us-ft   | U.S. Surveyor's Foot            |
-+----------+---------------------------------+
-|  us-yd   | U.S. Surveyor's Yard            |
-+----------+---------------------------------+
-|  us-ch   | U.S. Surveyor's Chain           |
-+----------+---------------------------------+
-|  us-mi   | U.S. Surveyor's Statute Mile    |
-+----------+---------------------------------+
-| ind-yd   | Indian Yard                     |
-+----------+---------------------------------+
-| ind-ft   | Indian Foot                     |
-+----------+---------------------------------+
-| ind-ch   | Indian Chain                    |
-+----------+---------------------------------+
-
-
-Time units
-###############################################################################
-
-In the table below all time units supported by PROJ.4 is listed.
-
-+--------------+-----------------------------+
-| mjd          | Modfied Julian date         |
-+--------------+-----------------------------+
-| decimalyear  | Decimal year                |
-+--------------+-----------------------------+
-| gps_week     | GPS Week                    |
-+--------------+-----------------------------+
-