NDVI from Google Earth Engine

Question

I want to get the NDVI of MODIS from Google Earth Engine in a country (Ireland), here is my code. It works, but it doesn't show on the map.

var dataset = ee.FeatureCollection('USDOS/LSIB/2013')
            .filterBounds(ee.Geometry.Point(-7.681, 53.43));

 var image = ee.Image().float().paint(dataset, 'iso_num'); ///import the vector data of the country globally

 var visParams = {
 palette: ['f5ff64', 'b5ffb4', 'beeaff', 'ffc0e8', '8e8dff', 'adadad'],
 min: 0.0,
 max: 894.0,
 opacity: 0.8,
 };

 Map.addLayer(image, visParams, 'USDOS/LSIB/2013'); ///show the data on the map


 var image1 = ee.ImageCollection('MODIS/MOD13A1')

          .filter(ee.Filter.date('2018-01-01', '2019-12-31'))

          .filterBounds(dataset);     ////import the MODIS ndvi data, filter the bounds with the dataset above

  var ndvi = image1.select('NDVI');


  var ndviVis = {
  palette: [
  'FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901',
  '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',
  '012E01', '011D01', '011301'
   ],
   };
  Map.addLayer(ndvi, ndviVis, 'NDVI');    

it runs, but only shows the boundary of Ireland. How to get the MODIS NDVI separately?

Answer 1

The problem is that MODIS/MOD13A1 doesn't contain any imagery in your date range. A minor issue is that image1 actually isn't an ee.Image, but an ee.ImageCollection. You can turn it into an image by calling mosaic(), median() etc. on it.

var image1 = ee.ImageCollection('MODIS/MOD13A1')
  // .filter(ee.Filter.date('2018-01-01', '2019-12-31'))
  .filter(ee.Filter.date('2016-01-01', '2017-01-01'))
  .filterBounds(dataset) ////import the MODIS ndvi data, filter the bounds with the dataset above
  .mosaic()

https://code.earthengine.google.com/a723f750f20883cb4e94b4c70cd303f2