ee.ImageCollection.merge

  • merge() combines two ImageCollections, resulting in a new collection containing all images from both inputs.

  • The output of merge() is a new ImageCollection with no duplicates.

  • This function is useful for consolidating image collections filtered by different criteria, such as date ranges or regions, as shown in the example with Sentinel-2 imagery filtered for different years.

 Merges two image collections into one. The result has all the images that were in either collection.

UsageReturns
ImageCollection.merge(collection2)ImageCollection
ArgumentTypeDetails
this: collection1ImageCollectionThe first collection to merge.
collection2ImageCollectionThe second collection to merge.

Examples

Code Editor (JavaScript)

// Sentinel-2 surface reflectance image collection.
var ic = ee.ImageCollection('COPERNICUS/S2_SR');

// Filter the images to those that intersect Mount Shasta for 3 months
// in 2019 and 2021 (two image collections).
var geom = ee.Geometry.Point(-122.196, 41.411);
var ic2018 = ic.filterBounds(geom).filterDate('2019-07-01', '2019-10-01');
print('2018 image collection', ic2018);
var ic2021 = ic.filterBounds(geom).filterDate('2021-07-01', '2021-10-01');
print('2021 image collection', ic2021);

// Merge the two image collections.
var icMerged = ic2018.merge(ic2021);
print('Merged image collection', icMerged);

Python setup

See the Python Environment page for information on the Python API and using geemap for interactive development.

import ee
import geemap.core as geemap

Colab (Python)

# Sentinel-2 surface reflectance image collection.
ic = ee.ImageCollection('COPERNICUS/S2_SR')

# Filter the images to those that intersect Mount Shasta for 3 months
# in 2019 and 2021 (two image collections).
geom = ee.Geometry.Point(-122.196, 41.411)
ic2018 = ic.filterBounds(geom).filterDate('2019-07-01', '2019-10-01')
print('2018 image collection:', ic2018.getInfo())
ic2021 = ic.filterBounds(geom).filterDate('2021-07-01', '2021-10-01')
print('2021 image collection:', ic2021.getInfo())

# Merge the two image collections.
ic_merged = ic2018.merge(ic2021)
print('Merged image collection:', ic_merged.getInfo())