From 5bb20f7ab438bcd3bafe187932629529f82f92fd Mon Sep 17 00:00:00 2001
From: Brendan Jurd <direvus@gmail.com>
Date: Sat, 20 Nov 2021 18:58:13 +1100
Subject: Docs: Add new Ellipsoids page to explain ellipsoidal parameters
 (#2922)

Co-authored-by: Rohit <rohitpingale103@gmail.com>
Co-authored-by: Brendan Jurd <brendan.jurd@geoplex.com.au>
Co-authored-by: Mike Taves <mwtoews@gmail.com>
---
 docs/images/general_ellipsoid.png | Bin 0 -> 79502 bytes
 docs/images/general_ellipsoid.svg | 227 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 227 insertions(+)
 create mode 100644 docs/images/general_ellipsoid.png
 create mode 100644 docs/images/general_ellipsoid.svg

(limited to 'docs/images')

diff --git a/docs/images/general_ellipsoid.png b/docs/images/general_ellipsoid.png
new file mode 100644
index 00000000..f6191d46
Binary files /dev/null and b/docs/images/general_ellipsoid.png differ
diff --git a/docs/images/general_ellipsoid.svg b/docs/images/general_ellipsoid.svg
new file mode 100644
index 00000000..d9e69b71
--- /dev/null
+++ b/docs/images/general_ellipsoid.svg
@@ -0,0 +1,227 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="297mm"
+   height="210mm"
+   viewBox="0 0 297 210"
+   version="1.1"
+   id="svg8"
+   inkscape:version="1.0.2 (e86c8708, 2021-01-15)"
+   sodipodi:docname="general_ellipsoid.svg"
+   inkscape:export-filename="general_ellipsoid.png"
+   inkscape:export-xdpi="96"
+   inkscape:export-ydpi="96">
+  <title
+     id="title957">Global and local fitting of an ellipsoid</title>
+  <defs
+     id="defs2" />
+  <sodipodi:namedview
+     id="base"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:pageopacity="0.0"
+     inkscape:pageshadow="2"
+     inkscape:zoom="1.031875"
+     inkscape:cx="374.70624"
+     inkscape:cy="396.85039"
+     inkscape:document-units="mm"
+     inkscape:current-layer="layer1"
+     inkscape:document-rotation="0"
+     showgrid="false"
+     inkscape:window-width="1598"
+     inkscape:window-height="1027"
+     inkscape:window-x="1856"
+     inkscape:window-y="35"
+     inkscape:window-maximized="0" />
+  <metadata
+     id="metadata5">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title>Global and local fitting of an ellipsoid</dc:title>
+        <cc:license
+           rdf:resource="http://creativecommons.org/publicdomain/zero/1.0/" />
+        <dc:date>2021-11-05</dc:date>
+        <dc:creator>
+          <cc:Agent>
+            <dc:title>Brendan Jurd</dc:title>
+          </cc:Agent>
+        </dc:creator>
+        <dc:contributor>
+          <cc:Agent>
+            <dc:title>Github user RohitPingale</dc:title>
+          </cc:Agent>
+        </dc:contributor>
+      </cc:Work>
+      <cc:License
+         rdf:about="http://creativecommons.org/publicdomain/zero/1.0/">
+        <cc:permits
+           rdf:resource="http://creativecommons.org/ns#Reproduction" />
+        <cc:permits
+           rdf:resource="http://creativecommons.org/ns#Distribution" />
+        <cc:permits
+           rdf:resource="http://creativecommons.org/ns#DerivativeWorks" />
+      </cc:License>
+    </rdf:RDF>
+  </metadata>
+  <g
+     inkscape:label="Layer 1"
+     inkscape:groupmode="layer"
+     id="layer1">
+    <path
+       style="fill:none;stroke:#999999;stroke-width:0.750858;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:1.50172, 0.75085800000000003;stroke-dashoffset:0;stroke-opacity:0.40080971"
+       d="M 156.44319,186.24994 V 117.82622"
+       id="path1482" />
+    <path
+       style="fill:none;stroke:#999999;stroke-width:0.896;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:1.792, 0.89600000000000002;stroke-dashoffset:0;stroke-opacity:0.40080971"
+       d="m 58.96348,118.22975 h 97.33606"
+       id="path935" />
+    <ellipse
+       style="fill:none;fill-rule:evenodd;stroke:#1a1a1a;stroke-width:2.065;stroke-miterlimit:4;stroke-dasharray:none"
+       id="path28"
+       cx="156.44319"
+       cy="118.22974"
+       rx="97.51786"
+       ry="69.16964" />
+    <path
+       style="fill:none;stroke:#999999;stroke-width:0.750858;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:1.50172, 0.750858;stroke-dashoffset:0;stroke-opacity:1"
+       d="M 156.44319,117.82622 V 49.402501"
+       id="path853" />
+    <path
+       style="fill:none;stroke:#999999;stroke-width:0.895554;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:1.79111, 0.895554;stroke-dashoffset:0;stroke-opacity:1"
+       d="M 156.29954,118.22975 H 253.6356"
+       id="path855" />
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:4.93889px;line-height:1.25;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.112651"
+       x="159.34363"
+       y="83.696701"
+       id="text859"><tspan
+         sodipodi:role="line"
+         id="tspan857"
+         x="159.34363"
+         y="83.696701"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:4.93889px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.112651">Semi-minor axis (<tspan
+   style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:4.93889px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.112651"
+   id="tspan879">b</tspan>)</tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:4.93889px;line-height:1.25;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.112651"
+       x="181.45177"
+       y="124.99306"
+       id="text885"><tspan
+         sodipodi:role="line"
+         x="181.45177"
+         y="124.99306"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:4.93889px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.112651"
+         id="tspan887">Semi-major axis (a)</tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;line-height:1.25;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.147382"
+       x="158.15302"
+       y="21.362297"
+       id="text895"><tspan
+         sodipodi:role="line"
+         id="tspan901"
+         x="158.15302"
+         y="21.362297"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.147382">Ellipsoid with global</tspan><tspan
+         sodipodi:role="line"
+         id="tspan903"
+         x="158.15302"
+         y="28.417847"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.147382">best fit to the geoid</tspan></text>
+    <path
+       id="ellipse899"
+       style="fill:none;fill-rule:evenodd;stroke:#0000ff;stroke-width:2.065;stroke-miterlimit:4;stroke-dasharray:none"
+       d="m 250.57205,126.24012 c 0,10.3563 0.79642,22.95383 -4.95439,31.77405 -6.79906,10.42796 -24.54555,8.97677 -37.34928,15.81511 -9.05328,4.83528 -21.79692,12.89112 -32.91197,15.26472 -27.66481,4.68453 -59.11518,-19.7509 -86.905434,-16.78315 -8.578355,1.27119 -8.339518,-7.31997 -9.983362,-11.76181 -3.87888,-10.48113 -13.772177,-10.54553 -20.07239,-18.16709 -8.475237,-10.25276 -2.858896,-6.47896 -2.858896,-19.22274 0,-2.23965 -2.00657,-5.68681 -1.713176,-7.87195 0.870667,-6.48458 3.619707,-12.4 6.838529,-18.237452 3.249123,-5.892404 4.215749,-16.320907 9.496636,-21.298025 5.233032,-4.932017 25.546827,-5.654431 32.420623,-9.436334 8.50097,-4.677165 7.64672,-15.157132 18.05385,-17.647255 9.7928,-2.343133 31.06499,3.472825 41.97223,3.472825 10.55663,0 18.25676,-4.355842 27.77783,-2.154984 18.79452,4.344476 20.90825,11.704407 32.74723,22.55346 5.8064,5.320891 20.10592,8.263235 25.90809,15.42057 6.94991,8.573135 1.53388,29.596795 1.53388,38.280055 z"
+       sodipodi:nodetypes="sssccsssssssssssss" />
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;line-height:1.25;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.147382"
+       x="251.19659"
+       y="68.192177"
+       id="text912"><tspan
+         sodipodi:role="line"
+         id="tspan910"
+         x="251.19659"
+         y="68.192177"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.147382">The geoid</tspan></text>
+    <ellipse
+       style="fill:#d40000;fill-opacity:0.360704;stroke:#d40000;stroke-width:1.5;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0"
+       id="path918"
+       cx="-40.997208"
+       cy="134.36771"
+       rx="41.438278"
+       ry="27.882259"
+       transform="rotate(-54.737323)" />
+    <path
+       style="fill:none;stroke:#0000ff;stroke-width:0.6;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+       d="M 53.766668,94.819757 36.67779,94.620025"
+       id="path920" />
+    <path
+       style="fill:none;stroke:#0000ff;stroke-width:0.6;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+       d="M 53.573102,147.37655 36.484224,147.17682"
+       id="path922" />
+    <path
+       id="path924"
+       style="fill:none;stroke:#0000ff;stroke-width:0.600001;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+       d="m 36.601427,114.28374 0.0702,-19.701134" />
+    <path
+       id="path936"
+       style="fill:none;stroke:#0000ff;stroke-width:0.600001;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+       d="m 36.484224,147.17682 0.07988,-22.41775" />
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;line-height:1.25;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.147382"
+       x="16.566299"
+       y="120.85104"
+       id="text930"><tspan
+         sodipodi:role="line"
+         id="tspan928"
+         x="16.566299"
+         y="120.85104"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.147382">Local region</tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;line-height:1.25;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.147382"
+       x="81.438286"
+       y="23.518936"
+       id="text945"><tspan
+         sodipodi:role="line"
+         id="tspan943"
+         x="81.438286"
+         y="23.518936"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.147382">Ellipsoid with best fit</tspan><tspan
+         sodipodi:role="line"
+         x="81.438286"
+         y="30.574486"
+         style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:5.64444px;font-family:'Linux Libertine Display O';-inkscape-font-specification:'Linux Libertine Display O, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-east-asian:normal;stroke-width:0.147382"
+         id="tspan949">to the local region</tspan></text>
+    <path
+       style="fill:none;stroke:#d40000;stroke-width:0.6;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+       d="M 102.52722,34.488045 92.360198,72.383272"
+       id="path951"
+       sodipodi:nodetypes="cc" />
+    <path
+       style="fill:none;stroke:#1a1a1a;stroke-width:0.6;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+       d="m 168.15066,31.407132 -3.6971,14.480289"
+       id="path953"
+       sodipodi:nodetypes="cc" />
+    <path
+       style="fill:none;stroke:#0000ff;stroke-width:0.6;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+       d="m 255.34049,72.691364 -3.6971,14.480289"
+       id="path955"
+       sodipodi:nodetypes="cc" />
+  </g>
+</svg>
-- 
cgit v1.2.3