ee.Terrain.aspect

Calcule l'aspect en degrés à partir d'un MNT.

Le gradient local est calculé à l'aide des voisins 4-connexes de chaque pixel. Des valeurs manquantes se produiront donc autour des bords d'une image.

Utilisation	Renvoie
ee.Terrain.aspect(input)	Image

Argument	Type	Détails
input	Image	Image d'altitude, en mètres.

Exemples

Éditeur de code (JavaScript)

// A digital elevation model.
var dem = ee.Image('NASA/NASADEM_HGT/001').select('elevation');

// Calculate slope. Units are degrees, range is [0,90).
var slope = ee.Terrain.slope(dem);

// Calculate aspect. Units are degrees where 0=N, 90=E, 180=S, 270=W.
var aspect = ee.Terrain.aspect(dem);

// Display slope and aspect layers on the map.
Map.setCenter(-123.457, 47.815, 11);
Map.addLayer(slope, {min: 0, max: 89.99}, 'Slope');
Map.addLayer(aspect, {min: 0, max: 359.99}, 'Aspect');

// Use the ee.Terrain.products function to calculate slope, aspect, and
// hillshade simultaneously. The output bands are appended to the input image.
// Hillshade is calculated based on illumination azimuth=270, elevation=45.
var terrain = ee.Terrain.products(dem);
print('ee.Terrain.products bands', terrain.bandNames());
Map.addLayer(terrain.select('hillshade'), {min: 0, max: 255}, 'Hillshade');;

Configuration de Python

Consultez la page Environnement Python pour en savoir plus sur l'API Python et sur l'utilisation de geemap pour le développement interactif.

import ee
import geemap.core as geemap

Colab (Python)

# A digital elevation model.
dem = ee.Image('NASA/NASADEM_HGT/001').select('elevation')

# Calculate slope. Units are degrees, range is [0,90).
slope = ee.Terrain.slope(dem)

# Calculate aspect. Units are degrees where 0=N, 90=E, 180=S, 270=W.
aspect = ee.Terrain.aspect(dem)

# Display slope and aspect layers on the map.
m = geemap.Map()
m.set_center(-123.457, 47.815, 11)
m.add_layer(slope, {'min': 0, 'max': 89.99}, 'Slope')
m.add_layer(aspect, {'min': 0, 'max': 359.99}, 'Aspect')

# Use the ee.Terrain.products function to calculate slope, aspect, and
# hillshade simultaneously. The output bands are appended to the input image.
# Hillshade is calculated based on illumination azimuth=270, elevation=45.
terrain = ee.Terrain.products(dem)
display('ee.Terrain.products bands', terrain.bandNames())
m.add_layer(terrain.select('hillshade'), {'min': 0, 'max': 255}, 'Hillshade')
m