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https://github.com/bellingcat/cloud-free-subregion.git
synced 2026-06-08 03:18:30 +03:00
Updated sentinel-2 (added 370 lines, deleted 1 line).
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logan
370
sentinel-2
370
sentinel-2
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var rgb = {
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bands: ["B4", "B3", "B2"],
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min: [0.025, 0.048, 0.065],
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max: [0.24, 0.249, 0.254],
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gamma: [2.2, 2.2, 2.2],
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};
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var rgb_sr = {
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bands: ["B4", "B3", "B2"],
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min: [0.03, 0.04, 0.03],
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max: [0.15, 0.15, 0.15],
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gamma: [1.0, 1.0, 1.0],
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};
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var veg_ir = {
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bands: ["B8", "B4", "B3"],
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min: [0.12, 0.03, 0.053],
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max: [0.5, 0.09, 0.12],
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gamma: [1.2, 1.2, 1.2],
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};
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var veg_ir_sr = {
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bands: ["B8", "B4", "B3"],
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min: [0.12, 0.03, 0.053],
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max: [0.5, 0.09, 0.12],
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gamma: [1.2, 1.2, 1.2],
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};
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function mergeObjects() {
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var res = {};
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for (var i = 0; i < arguments.length; i++) {
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for (var x in arguments[i]) {
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res[x] = arguments[i][x];
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}
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}
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return res;
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}
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function scale(image) {
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return image.divide(10000).copyProperties(image, ["system:time_start"]);
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}
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// Create a panel to hold the chart.
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var panel = ui.Panel();
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panel.style().set({
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width: "400px",
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height: "500px",
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position: "bottom-right",
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});
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var controlPanel = ui.Panel();
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controlPanel.style().set({
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width: "400px",
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// height: "100px",
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position: "top-right",
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});
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Map.add(panel);
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Map.add(controlPanel);
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var enhancedContrast = false;
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var falseColor = false;
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var sr = false;
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var limitToOnePerMonth = true;
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controlPanel.add(
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ui.Label(
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"Click on the map to get all cloud-free Sentinel-2 imagery for a 16 km^2 region around the selected point. Click on an individual image to add it to the map."
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)
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);
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controlPanel.add(
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ui.Checkbox({
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label: "IR False Color",
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value: false,
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onChange: function (ir) {
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falseColor = ir;
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},
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})
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);
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controlPanel.add(
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ui.Checkbox({
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label: "Atmospheric corrected (2018-)",
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value: false,
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onChange: function (c) {
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sr = c;
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},
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})
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);
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controlPanel.add(
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ui.Checkbox({
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label: "Enhance contrast",
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value: false,
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onChange: function (contrast) {
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enhancedContrast = contrast;
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},
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})
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);
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controlPanel.add(
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ui.Checkbox({
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label: "Limit to one image per month (recommended for large timeranges)",
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value: true,
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onChange: function (limit) {
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limitToOnePerMonth = limit;
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},
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})
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);
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function addClickedImage(image, date, color) {
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var collection = ee.ImageCollection(
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sr ? "COPERNICUS/S2_SR" : "COPERNICUS/S2"
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);
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image.get("system:index").evaluate(function (id) {
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var fullImage = collection
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.filterMetadata("system:index", "equals", id)
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.map(scale)
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.first();
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image = fullImage.resample("bicubic");
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// Define a Laplacian, or edge-detection kernel.
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var laplacian = ee.Kernel.laplacian8({ normalize: false, magnitude: 0.12 });
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// Apply the edge-detection kernel.
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var edgy = image.convolve(laplacian);
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var sharpened = image.subtract(edgy);
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Map.addLayer(sharpened, color, date.toISOString());
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});
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}
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function makeAddClickedImage(image, date, color) {
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return function () {
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addClickedImage(image, date, color);
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};
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}
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function makeDisplayThumbWithDate(image, panel, buffer, color) {
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return function (d) {
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var date = new Date(parseInt(d));
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panel.add(ui.Label(date.toISOString()));
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color.evaluate(function (color) {
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var thumb = ui.Thumbnail({
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image: image,
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params: mergeObjects(
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{
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dimensions: 256,
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region: buffer,
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format: "jpg",
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},
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color
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),
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onClick: makeAddClickedImage(image, date, color),
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});
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panel.add(thumb);
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});
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};
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}
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function filterOnePerMonth(collection) {
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var year = 2015;
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var month = 1;
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var images = [];
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while (year <= 2020) {
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while (month <= 12) {
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var start = year + "-" + ("0" + month).slice(-2) + "-01";
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var end = year + "-" + ("0" + (month + 1)).slice(-2) + "-01";
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if (month == 12) {
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end = year + 1 + "-01-01";
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}
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var image = collection.filterDate(start, end).sort("cover").first();
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images.push(image);
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month += 1;
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}
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year += 1;
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month = 1;
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}
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return ee.ImageCollection(images);
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}
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function getImagesAtPoint(coords) {
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panel.clear();
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Map.clear();
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Map.add(panel);
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Map.add(controlPanel);
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Map.onClick(getImagesAtPoint);
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var point = ee.Geometry.Point(coords.lon, coords.lat);
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var buffer = point.buffer(2000).bounds();
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function getCloudPixels(image) {
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var not_clouds = image.select("B2").lt(0.35).rename("not_clouds");
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image = image.addBands(not_clouds);
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var sum = image
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.select("not_clouds")
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.reduceRegion({
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reducer: ee.Reducer.sum(),
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geometry: image.geometry(),
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scale: 10,
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maxPixels: 1e9,
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})
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.get("not_clouds");
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var count = buffer.area(0.05).multiply(0.01);
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var cloud_cover_roi = ee
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.Number(1)
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.subtract(ee.Number(sum).divide(count))
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.multiply(100);
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var percentiles = image.mask(not_clouds).reduceRegion({
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reducer: ee.Reducer.percentile([1, 50, 99], ["p1", "p50", "p99"]),
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geometry: image.geometry(),
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scale: 10,
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maxPixels: 1e9,
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});
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image = image.set("count", count);
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image = image.set("sum", sum);
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image = image.set("cover", cloud_cover_roi);
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image = image.set("ir_p1", percentiles.get("B8_p1"));
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image = image.set("ir_p50", percentiles.get("B8_p50"));
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image = image.set("ir_p99", percentiles.get("B8_p99"));
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image = image.set("r_p1", percentiles.get("B4_p1"));
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image = image.set("r_p50", percentiles.get("B4_p50"));
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image = image.set("r_p99", percentiles.get("B4_p99"));
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image = image.set("g_p1", percentiles.get("B3_p1"));
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image = image.set("g_p50", percentiles.get("B3_p50"));
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image = image.set("g_p99", percentiles.get("B3_p99"));
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image = image.set("b_p1", percentiles.get("B2_p1"));
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image = image.set("b_p50", percentiles.get("B2_p50"));
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image = image.set("b_p99", percentiles.get("B2_p99"));
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return image;
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}
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Map.addLayer(buffer, { color: "FF0000" });
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// Load Sentinel-2 TOA reflectance data.
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var collection = ee
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.ImageCollection(sr ? "COPERNICUS/S2_SR" : "COPERNICUS/S2")
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.filterBounds(point)
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.filterDate("2015-01-01", "2020-12-30")
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// Pre-filter to get less cloudy granules.
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.filter(ee.Filter.lt("CLOUDY_PIXEL_PERCENTAGE", 15))
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.map(scale)
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.map(function (image) {
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return image.clip(buffer);
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})
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.map(getCloudPixels)
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.filter(ee.Filter.lt("cover", 5));
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if (limitToOnePerMonth) {
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collection = filterOnePerMonth(collection);
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}
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var color = sr
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? falseColor
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? veg_ir_sr
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: rgb_sr
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: falseColor
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? veg_ir
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: rgb;
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if (enhancedContrast) {
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var ir_p1 = collection.aggregate_mean("ir_p1");
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var ir_p99 = collection.aggregate_mean("ir_p99");
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var ir_p50 = collection.aggregate_mean("ir_p50");
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var r_p1 = collection.aggregate_mean("r_p1");
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var r_p99 = collection.aggregate_mean("r_p99");
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var r_p50 = collection.aggregate_mean("r_p50");
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var g_p1 = collection.aggregate_mean("g_p1");
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var g_p99 = collection.aggregate_mean("g_p99");
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var g_p50 = collection.aggregate_mean("g_p50");
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var b_p1 = collection.aggregate_mean("b_p1");
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var b_p99 = collection.aggregate_mean("b_p99");
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var b_p50 = collection.aggregate_mean("b_p50");
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var b_gamma = b_p50
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.subtract(b_p1)
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.divide(b_p99.subtract(b_p1))
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.log()
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.divide(ee.Number(0.5).log())
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.subtract(ee.Number(1))
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.divide(ee.Number(3))
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.add(ee.Number(1));
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var r_gamma = r_p50
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.subtract(r_p1)
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.divide(r_p99.subtract(r_p1))
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.log()
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.divide(ee.Number(0.5).log())
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.subtract(ee.Number(1))
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.divide(ee.Number(3))
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.add(ee.Number(1));
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var g_gamma = g_p50
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.subtract(g_p1)
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.divide(g_p99.subtract(g_p1))
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.log()
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.divide(ee.Number(0.5).log())
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.subtract(ee.Number(1))
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.divide(ee.Number(3))
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.add(ee.Number(1));
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var ir_gamma = ir_p50
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.subtract(ir_p1)
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.divide(ir_p99.subtract(ir_p1))
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.log()
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.divide(ee.Number(0.5).log())
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.subtract(ee.Number(1))
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.divide(ee.Number(3))
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.add(ee.Number(1));
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if (falseColor) {
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color = ee.Dictionary({
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bands: ["B8", "B4", "B3"],
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min: [ir_p1, r_p1, g_p1],
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max: [ir_p99, r_p99, g_p99],
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gamma: [ir_gamma, r_gamma, g_gamma],
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});
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} else {
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color = ee.Dictionary({
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bands: ["B4", "B3", "B2"],
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min: [r_p1, g_p1, b_p1],
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max: [r_p99, g_p99, b_p99],
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gamma: [r_gamma, g_gamma, b_gamma],
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});
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}
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} else {
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color = ee.Dictionary(color);
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}
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var size = collection.size();
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panel.add(
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ui.Label("Searching for cloud free images. This may take a few moments.")
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);
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size.evaluate(function (size) {
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if (size === 0) {
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panel.add(ui.Label("No cloud free images found"));
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}
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var listOfImages = collection.toList(size);
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for (var i = 0; i < size; i++) {
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var subpanel = ui.Panel();
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panel.add(subpanel);
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var image = ee.Image(listOfImages.get(i));
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var d = image
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.get("system:time_start")
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.evaluate(makeDisplayThumbWithDate(image, subpanel, buffer, color));
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}
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});
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}
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Map.onClick(getImagesAtPoint);
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