I am writing a script to extract the time series soil moisture values from SMAP soil moisture data using point shapefile and plot it on a line graph in the Google Earth Engine. As SMAP having the daily data coverage but I am getting the pixel values three days interval. Can anyone tell me where is the wrong with my code and addition to that I want to extract the time information also along with date and export it as CSV to Drive.

Below code, I am working

#Point shape file I uploaded, if I can add manually coordinate, please tell me (Not from geomarty addition)
var shp=ee.FeatureCollection('users/SWAT/C01');

// which dataset + where + when
var imageCollection = ee.ImageCollection('NASA_USDA/HSL/SMAP_soil_moisture')

// select bands -> ssm = surface soil moisture (%)
var soilmoisture = imageCollection.select('smp');

// gget scale
var scale = imageCollection.first().projection().nominalScale();

// Take average
var imageCollection = imageCollection.map(function(image){
  return ee.Image(image.setMulti(image.reduceRegion(ee.Reducer.mean(), shp, scale)));

// Get the mean from the dictionary and print it.
var means = imageCollection.aggregate_array('smp');
print('Soil Moisture (%)', means);
// put in a chart
print(ui.Chart.image.seriesByRegion(imageCollection, shp, ee.Reducer.mean(), 'smp', scale));

// Get the mean from the dictionary and print it.
var meanDict = soilmoisture.mean().reduceRegion(ee.Reducer.mean(), shp, scale);
print('Soil Moisture (%)', meanDict);

Map.centerObject(shp, 10);
Map.addLayer(soilmoisture, {min: 0, max: 1}, 'soilmoister imageCollection');  


1 Answer 1


I would refer to this link and see if it helps get you started:


Code from link:

// Load Landsat 8 top-of-atmosphere (TOA) input imagery.
var collection = ee.ImageCollection('LANDSAT/LC08/C01/T1_TOA').select('B[1-7]');

// Define a region of interest as a buffer around a point.
var geom = ee.Geometry.Point(-122.08384, 37.42503).buffer(500);

// Create and print the chart.
print(ui.Chart.image.series(collection, geom, ee.Reducer.mean(), 30));

You can export the time series from there.

Also some more in depth coverage here:


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