Differences

This shows you the differences between two versions of the page.

--- projects:voyc:map_projections [2024/08/17 23:16] – [Lambert azimuthal equal-area projection] jhagstrand
+++ projects:voyc:map_projections [2024/08/19 08:46] (current) – jhagstrand
@@ Line 3: / Line 3: @@
 ======Map Projections======
-see [[Gallery of Map Projections]]
+see [[Gallery of Map Projections]]\\
+see [[Thematic Maps]]\\
 Projecting a 3D sphere onto a 2D map results in distortions.
@@ Line 35: / Line 36: @@
-===== Web Mercator Projection =====
+===== Web Mercator =====
-https://en.wikipedia.org/wiki/Web_Mercator_projection\\
+In **2005**, Google Maps introduced a modification to the Mercator to allow faster calculations.\\
-https://gist.github.com/shiffman/a0d2fde31f571163c730ba0da4a01c82\\
-https://developer.tomtom.com/blog/decoded/understanding-map-tile-grids-and-zoom-levels\\
-mercator uses ellipsoid model, has time-consuming calculation\\
+Web Mercator uses a spheroid model instead of Mercator's ellipsoid model.\\
-webmercator uses spheroid model, introduces "zoom level", and simplifies the calculation\\
+This allows a faster calculation but sacrifices some accuracy at low scales.\\
-a sphere is a subset of an ellipsoid object\\
-Similar to mercator, but with much faster calculation.
-Introduces "zoom level"
-[[https://developer.tomtom.com/map-display-api/documentation/tomtom-orbis-maps/zoom-levels-and-tile-grid|TomTom]]
-Introduced by Google Maps in 2005.\\
-Now used in most online street mapping systems.\\
+Web Mercator also introduces "zoom level".  Explained here at
+[[https://developer.tomtom.com/map-display-api/documentation/tomtom-orbis-maps/zoom-levels-and-tile-grid|TomTom]].
+Web Mercator is now used in most online street mapping systems.\\
 ===== Comparisions =====
@@ Line 94: / Line 85: @@
 This is the Web Mercator variation used by Google Maps and most other online street mapping programs because of the speed of calculation.
+=====Voyc Petri Projection=====
+==Purpose==
+Demonstrate the expansion of life forms from Africa outwards to the rest of the world.\\
+see [[Thematic Maps#Out of Africa|Out of Africa]]\\
+==Requirements==
+  * circular shape, 86 mm diameter, to fit in a petri dish
+  * origin in Lake Victoria
+  * maintain relationship between eastern Russia and Alaska
+  * equal-area
 =====References=====