Junções invertidas

Suponha que o objetivo da mesclagem seja reter todas as imagens na coleção primary que não estão na coleção secondary. É possível realizar esse tipo de mesclagem invertida usando ee.Join.inverted().

Editor de código (JavaScript)

// Load a Landsat 8 image collection at a point of interest.
var collection = ee.ImageCollection('LANDSAT/LC08/C02/T1_TOA')
    .filterBounds(ee.Geometry.Point(-122.09, 37.42));

// Define start and end dates with which to filter the collections.
var april = '2014-04-01';
var may = '2014-05-01';
var june = '2014-06-01';
var july = '2014-07-01';

// The primary collection is Landsat images from April to June.
var primary = collection.filterDate(april, june);

// The secondary collection is Landsat images from May to July.
var secondary = collection.filterDate(may, july);

// Use an equals filter to define how the collections match.
var filter = ee.Filter.equals({
  leftField: 'system:index',
  rightField: 'system:index'
});

// Define the join.
var invertedJoin = ee.Join.inverted();

// Apply the join.
var invertedJoined = invertedJoin.apply(primary, secondary, filter);

// Print the result.
print('Inverted join:', invertedJoined);

Configuração do Python

Consulte a página Ambiente Python para informações sobre a API Python e o uso de geemap para desenvolvimento interativo.

import ee
import geemap.core as geemap

Colab (Python)

# Load a Landsat 8 image collection at a point of interest.
collection = ee.ImageCollection('LANDSAT/LC08/C02/T1_TOA').filterBounds(
    ee.Geometry.Point(-122.09, 37.42)
)

# Define start and end dates with which to filter the collections.
april = '2014-04-01'
may = '2014-05-01'
june = '2014-06-01'
july = '2014-07-01'

# The primary collection is Landsat images from April to June.
primary = collection.filterDate(april, june)

# The secondary collection is Landsat images from May to July.
secondary = collection.filterDate(may, july)

# Use an equals filter to define how the collections match.
filter = ee.Filter.equals(leftField='system:index', rightField='system:index')

# Define the join.
inverted_join = ee.Join.inverted()

# Apply the join.
inverted_joined = inverted_join.apply(primary, secondary, filter)

# Print the result.
display('Inverted join:', inverted_joined)

A saída será semelhante a esta:

Image LANDSAT/LC08/C02/T1_TOA/LC08_044034_20140403 (17 bands)
Image LANDSAT/LC08/C02/T1_TOA/LC08_044034_20140419 (17 bands)

A mesclagem invertida contém as imagens de 3 e 19 de abril, indicando as imagens presentes na coleção primary, mas não na coleção secondary.