I tried to generate a time series chart of NDVI using Sentinel-2 data for multiple points. But the chart has vertical plots with two values for same point and same date.

Here is the code:

var points = ee.FeatureCollection([
ee.Feature(geometry2, {label: 'm1'}),
ee.Feature(geometry3, {label: 'm2'}),
ee.Feature(geometry4, {label: 'm3'}),
ee.Feature(geometry5, {label: 'm4'}),
ee.Feature(geometry6, {label: 'm5'}),
ee.Feature(geometry7, {label: 'm6'}),
ee.Feature(geometry8, {label: 'm7'}),
ee.Feature(geometry9, {label: 'm8'}),
ee.Feature(geometry10, {label: 'm9'}),
ee.Feature(geometry11, {label: 'm10'})


// NDVI calculation

var addNDVI = function(image) {
  return image.addBands(image.normalizedDifference(['B8', 'B4']));


  var with_ndvi = puli.map(addNDVI);

  var rgb_vis = {min: 0, max: 5000, bands: ['B4', 'B3', 'B2']};
  Map.addLayer(puli, rgb_vis, 'RGB');
  Map.addLayer(with_ndvi, {bands: 'nd', min: 0, max: 1}, 'NDVI');

   // Time Series Analysis for NDVI

var TimeSeriesndvi = ui.Chart.image.seriesByRegion(with_ndvi,points,ee.Reducer.mean(),'nd',200, 'system:time_start', 'label')
          title: 'NDVI variations',
          vAxis: {title: 'NDVI'},
          lineWidth: 1,
          pointSize: 4,
          series: {
          // 0: {color: 'FF0000'}, 
          // 1: {color: '00FF00'},  
          //   2: {color: '0000FF'}, 
  • Your code seems to be right. However as we don´t know what the variable puli is (I assume is a filtered collection of Sentinel-2) and where your geometries are, it is not possible to help you. If you have duplicated values, it is probably that your points are in an overlapping area between two tiles, but we need to know where those points are to be sure. – HMSP Sep 30 '19 at 13:59

Alternatively, there's a way to do that in LV.

  • Open LV and locate an area of your interest and then highlight it with AOI tool.
  • Click on “Time series analysis” icon on the left of the screen
  • Set the values needed and hit "apply"

enter image description here

You can then export the data wherever you need it.


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