Esri satellite basemap

gistfile1.txt

        new ol.layer.Tile({
          type: 'base',
          title: 'ESRI world imagery',
          visible: false,
          source: new ol.source.XYZ({
            attributions: [
              new ol.Attribution({
                html: 'Tiles © Esri — Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGP, UPR-EGP, and the GIS User Community'
              })
            ],
            url: 'http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}'
          })
        })