From fa2fcad163b8068d418fba1924a19f35b071d7d3 Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Tue, 3 Apr 2018 11:54:36 +0200 Subject: Add yyyymmdd temporal unit to unitconvert docs --- docs/source/operations/conversions/unitconvert.rst | 2 ++ 1 file changed, 2 insertions(+) (limited to 'docs/source/operations') diff --git a/docs/source/operations/conversions/unitconvert.rst b/docs/source/operations/conversions/unitconvert.rst index 50ac832c..bc422afb 100644 --- a/docs/source/operations/conversions/unitconvert.rst +++ b/docs/source/operations/conversions/unitconvert.rst @@ -109,4 +109,6 @@ In the table below all time units supported by PROJ is listed. +--------------+-----------------------------+ | gps_week | GPS Week | +--------------+-----------------------------+ +| yyyymmdd | Date in yyyymmdd format | ++--------------+-----------------------------+ -- cgit v1.2.3 From 89af2753651f8c21eae9df631a71c0a3b03bcc3b Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Mon, 9 Apr 2018 02:02:26 +0200 Subject: Fix bad example in eqc docs --- docs/source/operations/projections/eqc.rst | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'docs/source/operations') diff --git a/docs/source/operations/projections/eqc.rst b/docs/source/operations/projections/eqc.rst index be431977..5833bd61 100644 --- a/docs/source/operations/projections/eqc.rst +++ b/docs/source/operations/projections/eqc.rst @@ -64,9 +64,8 @@ Example using EPSG 32662 (WGS84 Plate Carrée):: Example using Plate Carrée projection with true scale at latitude 30° and central meridian 90°W:: - $ echo -88 30 | proj +proj=eqc +lat_ts=30 +lat_0=90w - -8483684.61 13358338.90 - + $ echo -88 30 | proj +proj=eqc +lat_ts=30 +lon_0=90w + 192811.01 3339584.72 Mathematical definition ####################### -- cgit v1.2.3 From 3a2ddb6c6efbccf388ea89e177ca51fd25946ecf Mon Sep 17 00:00:00 2001 From: Even Rouault Date: Sat, 7 Apr 2018 13:41:12 +0200 Subject: Add webmerc projection --- docs/source/operations/projections/index.rst | 1 + docs/source/operations/projections/webmerc.rst | 78 ++++++++++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 docs/source/operations/projections/webmerc.rst (limited to 'docs/source/operations') diff --git a/docs/source/operations/projections/index.rst b/docs/source/operations/projections/index.rst index 9255d9fd..77decd6c 100644 --- a/docs/source/operations/projections/index.rst +++ b/docs/source/operations/projections/index.rst @@ -141,6 +141,7 @@ Projections map the spherical 3D space to a flat 2D space. wag5 wag6 wag7 + webmerc weren wink1 wink2 diff --git a/docs/source/operations/projections/webmerc.rst b/docs/source/operations/projections/webmerc.rst new file mode 100644 index 00000000..0c465afc --- /dev/null +++ b/docs/source/operations/projections/webmerc.rst @@ -0,0 +1,78 @@ +.. _webmerc: + +******************************************************************************** +Web Mercator / Pseudo Mercator +******************************************************************************** + +The Web Mercator / Pseudo Mercator projection is a cylindrical map projection. +This is a variant of the regular :ref:`merc` projection, except that the computation +is done on a sphere, using the semi-major axis of the ellipsoid. + +From `Wikipedia `_: + + This projection is widely used by the Web Mercator, Google Web Mercator, + Spherical Mercator, WGS 84 Web Mercator[1] or WGS 84/Pseudo-Mercator is a + variant of the Mercator projection and is the de facto standard for Web + mapping applications. [...] + It is used by virtually all major online map providers [...] + Its official EPSG identifier is EPSG:3857, although others have been used + historically. + + ++---------------------+----------------------------------------------------------+ +| **Classification** | Cylindrical (non conformant if used with ellipsoid) | ++---------------------+----------------------------------------------------------+ +| **Version** | Added in proj 5.1.0 | ++---------------------+----------------------------------------------------------+ +| **Available forms** | Forward and inverse, spherical projection | ++---------------------+----------------------------------------------------------+ +| **Defined area** | Global, but best used near the equator | ++---------------------+----------------------------------------------------------+ +| **Options** | Neither lat_0, lon_0, lat_ts or k_0 should be used. | ++---------------------+----------------------------------------------------------+ + +Usage +######## + +Example:: + + $ echo 2 49 | proj +proj=webmerc +datum=WGS84 + 222638.98 6274861.39 + +Mathematical definition +####################### + +The formulas describing the Mercator projection are all taken from G. Evenden's libproj manuals [Evenden2005]_. + +Forward projection +================== + +.. math:: + + x = \lambda + +.. math:: + + y = \ln \left[ \tan \left(\frac{\pi}{4} + \frac{\phi}{2} \right) \right] + + +Inverse projection +================== + +.. math:: + + \lambda = {x} + +.. math:: + + \phi = \frac{\pi}{2} - 2 \arctan \left[ e^{-y} \right] + + + +Further reading +############### + +#. `Wikipedia `_ + + + -- cgit v1.2.3 From bc8026a46606abf48679d81d80991623d5b91ca7 Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Mon, 9 Apr 2018 22:27:59 +0200 Subject: Add description of projection and +lat_b parameter --- docs/source/operations/projections/airy.rst | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'docs/source/operations') diff --git a/docs/source/operations/projections/airy.rst b/docs/source/operations/projections/airy.rst index d2730592..eefda4e9 100644 --- a/docs/source/operations/projections/airy.rst +++ b/docs/source/operations/projections/airy.rst @@ -3,6 +3,11 @@ ******************************************************************************** Airy ******************************************************************************** + +The Airy projection is an azimuthal minimum error projection for the region +within the small or great circle defined by an angular distance, +:math:`\phi_b`, from the tangency point of the plane :math:`( \lambda_0, \phi_0 )`. + +---------------------+----------------------------------------------------------+ | **Classification** | | +---------------------+----------------------------------------------------------+ @@ -14,7 +19,10 @@ Airy +---------------------+----------------------------------------------------------+ | **Options** | +---------------------+----------------------------------------------------------+ -| `+lat_b` | | +| `+lat_b` | Angular distance from tangency point of the plane | +| | :math:`( \lambda_0, \phi_0 )` where the error is kept at | +| | minimum. Defaults to :math:`90^{\circ}` which is | +| | suitable for hemispherical maps. | +---------------------+----------------------------------------------------------+ | `+no_cut` | Do not cut at hemisphere limit | +---------------------+----------------------------------------------------------+ -- cgit v1.2.3 From 60d86d4914b816143b4145ccae0def0420f2a70d Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Wed, 11 Apr 2018 23:11:23 +0200 Subject: Update docs for nsper --- docs/source/operations/projections/nsper.rst | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'docs/source/operations') diff --git a/docs/source/operations/projections/nsper.rst b/docs/source/operations/projections/nsper.rst index 4a8651fc..3f46f2b4 100644 --- a/docs/source/operations/projections/nsper.rst +++ b/docs/source/operations/projections/nsper.rst @@ -4,7 +4,28 @@ Near-sided perspective ******************************************************************************** +The near-sided perspective projection simulates a view from a height +:math:`h` similar to how a satellite in orbit would see it. + ++---------------------+-------------------------------------------------------------+ +| **Classification** | Azimuthal. Neither conformal nor equal area. | ++---------------------+-------------------------------------------------------------+ +| **Available forms** | Forward and inverse spherical projection | ++---------------------+-------------------------------------------------------------+ +| **Defined area** | Global, although for one hemisphere at a time. | ++---------------------+-------------------------------------------------------------+ +| **Options** | ++---------------------+-------------------------------------------------------------+ +| `+h` | Height of the view point above the Earth and must be in | +| | the same units as the radius of the sphere. Required. | ++---------------------+-------------------------------------------------------------| +| `+lat_0` | Latitude (in degrees) of the view position. Defaults to 0. | ++---------------------+-------------------------------------------------------------+ +| `+lon_0` | Longitude (in degrees) of the view position. Defaults to 0. | ++---------------------+-------------------------------------------------------------+ + + .. image:: ./images/nsper.png :scale: 50% - :alt: Near-sided perspective + :alt: Near-sided perspective -- cgit v1.2.3 From b0fa1a508d4827032f81ae03d29a54e3091ae47b Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Sun, 15 Apr 2018 18:41:48 +0200 Subject: Update aeqd docs with note of area of use for +guam option --- docs/source/operations/projections/aeqd.rst | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'docs/source/operations') diff --git a/docs/source/operations/projections/aeqd.rst b/docs/source/operations/projections/aeqd.rst index 32165e49..d4baa8b6 100644 --- a/docs/source/operations/projections/aeqd.rst +++ b/docs/source/operations/projections/aeqd.rst @@ -12,7 +12,10 @@ Azimuthal Equidistant +---------------------+----------------------------------------------------------+ | **Options** | +---------------------+----------------------------------------------------------+ -| `+guam` | Use Guam elliptical formulas. Defaults to false. | +| `+guam` | Use Guam elliptical formulas. Only accurate near the | +| | Island of Guam (:math:`\lambda\approx 144.5^{\circ}`, | +| | :math:`\phi\approx 13.5^{\circ}`) | +| | Defaults to false. | +---------------------+----------------------------------------------------------+ -- cgit v1.2.3 From 410a515228166399f8c145568f20a7799a450757 Mon Sep 17 00:00:00 2001 From: mwtoews Date: Sun, 22 Apr 2018 21:55:44 +1200 Subject: Fix subtle typo in table syntax --- docs/source/operations/projections/nsper.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'docs/source/operations') diff --git a/docs/source/operations/projections/nsper.rst b/docs/source/operations/projections/nsper.rst index 3f46f2b4..d204305b 100644 --- a/docs/source/operations/projections/nsper.rst +++ b/docs/source/operations/projections/nsper.rst @@ -18,7 +18,7 @@ The near-sided perspective projection simulates a view from a height +---------------------+-------------------------------------------------------------+ | `+h` | Height of the view point above the Earth and must be in | | | the same units as the radius of the sphere. Required. | -+---------------------+-------------------------------------------------------------| ++---------------------+-------------------------------------------------------------+ | `+lat_0` | Latitude (in degrees) of the view position. Defaults to 0. | +---------------------+-------------------------------------------------------------+ | `+lon_0` | Longitude (in degrees) of the view position. Defaults to 0. | -- cgit v1.2.3