Bare Soil Marker
//VERSION=3
//Author: Domagoj Korais
function setup() {
return {
input: [{
bands: ["B02", "B03", "B04", "B05", "B07", "B08", "B11"],
units: "reflectance"
}],
output: {
id:"default",
bands: 3,
sampleType: "AUTO"
}
}
}
function evaluatePixel(sample) {
var NBSI = ((sample.B11 + sample.B04)-(sample.B08 + sample.B02))/((sample.B11 + sample.B04)+(sample.B08 + sample.B02))
var NDVI = index(sample.B08, sample.B04);
var NDVI_RE3 = index(sample.B08, sample.B07);
var CL_RE = sample.B07 / sample.B05 - 1;
var is_bare_soil = NDVI <= -0.1 ? false : predict(NBSI, NDVI, NDVI_RE3, CL_RE) > 0.5;
if (is_bare_soil) {
return [2.5 * sample.B04,
2.5 * sample.B03,
0.3 + 2.5 * sample.B02]
}
return [2.5 * sample.B04,
2.5 * sample.B03,
2.5 * sample.B02]
}
var DecisionTreeClassifier = function() {
var findMax = function(nums) {
var index = 0;
for (var i = 0; i < nums.length; i++) {
index = nums[i] > nums[index] ? i : index;
}
return index;
};
this.predict = function(features) {
var classes = new Array(2);
if (features[1] <= 0.2880808413028717) {
if (features[2] <= -0.001884871511720121) {
if (features[2] <= -0.01514277933165431) {
if (features[0] <= -0.05856157839298248) {
if (features[3] <= 0.4919503927230835) {
if (features[1] <= 0.22891760617494583) {
classes[0] = 109;
classes[1] = 75;
} else {
classes[0] = 77;
classes[1] = 5;
}
} else {
if (features[3] <= 0.6081486344337463) {
classes[0] = 47;
classes[1] = 128;
} else {
classes[0] = 22;
classes[1] = 311;
}
}
} else {
if (features[1] <= 0.23794686794281006) {
if (features[3] <= 0.24695706367492676) {
classes[0] = 51;
classes[1] = 132;
} else {
classes[0] = 352;
classes[1] = 3683;
}
} else {
if (features[3] <= 0.4766134023666382) {
classes[0] = 91;
classes[1] = 57;
} else {
classes[0] = 209;
classes[1] = 1278;
}
}
}
} else {
if (features[0] <= -0.01485772943124175) {
if (features[3] <= 0.46598660945892334) {
if (features[1] <= 0.23513969033956528) {
classes[0] = 80;
classes[1] = 30;
} else {
classes[0] = 83;
classes[1] = 4;
}
} else {
classes[0] = 38;
classes[1] = 42;
}
} else {
if (features[1] <= 0.24381835758686066) {
if (features[0] <= 0.017081347294151783) {
classes[0] = 37;
classes[1] = 60;
} else {
classes[0] = 72;
classes[1] = 437;
}
} else {
if (features[3] <= 0.4962599277496338) {
classes[0] = 84;
classes[1] = 43;
} else {
classes[0] = 23;
classes[1] = 66;
}
}
}
}
} else {
if (features[2] <= 0.012518306728452444) {
if (features[0] <= 0.011857263278216124) {
if (features[3] <= 0.44026511907577515) {
if (features[0] <= -0.025940910913050175) {
classes[0] = 155;
classes[1] = 2;
} else {
classes[0] = 122;
classes[1] = 13;
}
} else {
classes[0] = 58;
classes[1] = 38;
}
} else {
if (features[1] <= 0.21599827706813812) {
classes[0] = 44;
classes[1] = 86;
} else {
if (features[3] <= 0.4378824234008789) {
classes[0] = 145;
classes[1] = 37;
} else {
classes[0] = 57;
classes[1] = 55;
}
}
}
} else {
if (features[3] <= 0.4603644013404846) {
if (features[1] <= 0.21943768113851547) {
if (features[0] <= 0.021366839297115803) {
classes[0] = 131;
classes[1] = 4;
} else {
classes[0] = 58;
classes[1] = 25;
}
} else {
if (features[3] <= 0.42150408029556274) {
classes[0] = 982;
classes[1] = 19;
} else {
classes[0] = 237;
classes[1] = 14;
}
}
} else {
classes[0] = 84;
classes[1] = 26;
}
}
}
} else {
if (features[2] <= -0.047297170385718346) {
if (features[1] <= 0.40251147747039795) {
if (features[3] <= 0.6912856698036194) {
classes[0] = 114;
classes[1] = 25;
} else {
if (features[1] <= 0.3502514660358429) {
if (features[3] <= 0.7766227126121521) {
classes[0] = 29;
classes[1] = 74;
} else {
classes[0] = 64;
classes[1] = 516;
}
} else {
if (features[0] <= -0.027021611109375954) {
classes[0] = 84;
classes[1] = 236;
} else {
classes[0] = 72;
classes[1] = 30;
}
}
}
} else {
if (features[1] <= 0.4671569764614105) {
if (features[0] <= -0.05327927693724632) {
if (features[2] <= -0.0706191249191761) {
classes[0] = 43;
classes[1] = 41;
} else {
classes[0] = 99;
classes[1] = 40;
}
} else {
if (features[1] <= 0.4272315502166748) {
classes[0] = 67;
classes[1] = 18;
} else {
classes[0] = 121;
classes[1] = 9;
}
}
} else {
if (features[3] <= 1.3283718824386597) {
classes[0] = 137;
classes[1] = 16;
} else {
if (features[2] <= -0.08075670152902603) {
classes[0] = 75;
classes[1] = 5;
} else {
classes[0] = 453;
classes[1] = 4;
}
}
}
}
} else {
if (features[1] <= 0.3474765121936798) {
if (features[3] <= 0.5934110283851624) {
if (features[2] <= 0.003244615043513477) {
if (features[0] <= -0.03575599752366543) {
classes[0] = 330;
classes[1] = 39;
} else {
classes[0] = 360;
classes[1] = 138;
}
} else {
if (features[2] <= 0.01407763920724392) {
classes[0] = 607;
classes[1] = 57;
} else {
classes[0] = 2837;
classes[1] = 48;
}
}
} else {
if (features[2] <= -0.021189325489103794) {
if (features[0] <= 0.008428129367530346) {
classes[0] = 113;
classes[1] = 342;
} else {
classes[0] = 82;
classes[1] = 90;
}
} else {
if (features[2] <= 0.010304238181561232) {
classes[0] = 290;
classes[1] = 266;
} else {
classes[0] = 142;
classes[1] = 28;
}
}
}
} else {
if (features[2] <= 0.00489223818294704) {
if (features[1] <= 0.4410252124071121) {
if (features[0] <= -0.034201690927147865) {
classes[0] = 1971;
classes[1] = 653;
} else {
classes[0] = 2273;
classes[1] = 234;
}
} else {
if (features[3] <= 1.035286784172058) {
classes[0] = 1973;
classes[1] = 195;
} else {
classes[0] = 9665;
classes[1] = 144;
}
}
} else {
if (features[2] <= 0.016115683130919933) {
if (features[1] <= 0.4877214878797531) {
classes[0] = 2990;
classes[1] = 137;
} else {
classes[0] = 1448;
classes[1] = 18;
}
} else {
if (features[0] <= -0.04386013746261597) {
classes[0] = 7991;
classes[1] = 130;
} else {
classes[0] = 7008;
classes[1] = 44;
}
}
}
}
}
}
return findMax(classes);
};
};
function predict(NBSI, NDVI, NDVI_RE3, CL_RE){
var clf = new DecisionTreeClassifier();
return [1/(1+Math.exp(-1*clf.predict([NBSI, NDVI, NDVI_RE3, CL_RE])))];
}Evaluate and Visualize
General description of the script
The bare soil marker identifies all observations in which the feature of interest (FOI) is bare — with exposed bare soil as a result of ploughing or covered with non-photosynthetic vegetation as a consequence of harvest or vegetation drying up on the field.
For detailed information about the marker read the relative blog post.
Pixels identifies as bare soil are colored in blue.
Author of the script
Domagoj Korais.
Description of representative images
Bare soil script applied around lake Balaton, Hungary.
Image taken on 14/09/2020.
