Add light pollution layers

layers/index.js

@@ -11,6 +11,7 @@ import census_bureau from './census-bureau/index.js';
 import states from './states/index.js';
 import national_land from './national-land/index.js';
 import cellular from './cellular.js';
+import light_pollution from './light_pollution.js';
 
 const layerCategories = [
     { // Base maps
@@ -79,6 +80,7 @@ const layerCategories = [
     states,
     national_land,
     cellular,
+    light_pollution,
 ];
 
 export default layerCategories;

layers/light_pollution.js

@@ -0,0 +1,28 @@
+import { XYZ } from 'ol/source.js';
+import TileLayer from 'ol/layer/Tile';
+
+let layers = [];
+
+["2006", "2016", "2020"].forEach(year => {
+    layers.push({
+        name: `<a href='https://djlorenz.github.io/astronomy/lp${year}/'>djlorenz ${year}</a>`,
+        layer:
+        new TileLayer({
+            source: new XYZ({
+                attributions: `David Lorenz's <a href=http://djlorenz.github.io/astronomy/lp${year}/>Light Pollution Atlas ${year}</a>`,
+                maxZoom: 6,
+                tilePixelRatio:4,
+                tileSize: (1024, 1024),
+                transition: 0,
+                url: `https://djlorenz.github.io/astronomy/lp${year}/overlay/tiles/tile_{z}_{x}_{y}.png`,
+            }),
+            visible:true,
+            opacity: 0.5,
+        }),
+    });
+});
+
+export default {
+    name: "Light Pollution",
+    layers: layers,
+};