Created
May 31, 2023 14:35
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//VERSION=3 | |
//Basic initialization setup function | |
function setup() { | |
return { | |
//List of all bands, that will be used in the script, either for visualization or for choosing best pixel | |
input: [{ | |
bands: [ | |
"B04", | |
"B08" | |
] | |
}], | |
//This can always be the same if one is doing RGB images | |
output: { bands: 3 }, | |
mosaicking: "ORBIT" | |
} | |
} | |
/* | |
In this function we limit the scenes, which are used for processing. | |
These are based also on input variables, coming from Playground. | |
E.g. if one sets date "2017-03-01" ("TO date") and cloud coverage filter 30%, | |
all scenes older than 2017-03-01 with cloud coverage 30% will be checked against | |
further conditions in this function. | |
The more scenes there are, longer it will take to process the data. | |
After 60 seconds of processing, there will be a timeout. | |
*/ | |
function preProcessScenes (collections) { | |
collections.scenes.orbits = collections.scenes.orbits.filter(function (orbit) { | |
var orbitDateFrom = new Date(orbit.dateFrom) | |
return orbitDateFrom.getTime() >= (collections.to.getTime()-3*31*24*3600*1000); | |
}) | |
return collections | |
} | |
function calcNDVI(sample) { | |
var denom = sample.B04+sample.B08; | |
return ((denom!=0) ? (sample.B08-sample.B04) / denom : 0.0); | |
} | |
function evaluatePixel(samples) { | |
var max = 0; | |
for (var i=0;i<samples.length;i++) { | |
var ndvi = calcNDVI(samples[i]); | |
max = ndvi > max ? ndvi:max; | |
} | |
if (max<-1.1) return [0,0,0]; | |
else if (max<-0.2) return [0.75,0.75,0.75]; | |
else if (max<-0.1) return [0.86,0.86,0.86]; | |
else if (max<0) return [1,1,0.88]; | |
else if (max<0.025) return [1,0.98,0.8]; | |
else if (max<0.05) return [0.93,0.91,0.71]; | |
else if (max<0.075) return [0.87,0.85,0.61]; | |
else if (max<0.1) return [0.8,0.78,0.51]; | |
else if (max<0.125) return [0.74,0.72,0.42]; | |
else if (max<0.15) return [0.69,0.76,0.38]; | |
else if (max<0.175) return [0.64,0.8,0.35]; | |
else if (max<0.2) return [0.57,0.75,0.32]; | |
else if (max<0.25) return [0.5,0.7,0.28]; | |
else if (max<0.3) return [0.44,0.64,0.25]; | |
else if (max<0.35) return [0.38,0.59,0.21]; | |
else if (max<0.4) return [0.31,0.54,0.18]; | |
else if (max<0.45) return [0.25,0.49,0.14]; | |
else if (max<0.5) return [0.19,0.43,0.11]; | |
else if (max<0.55) return [0.13,0.38,0.07]; | |
else if (max<0.6) return [0.06,0.33,0.04]; | |
else return [0,0.27,0]; | |
} |
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