ALOS DSM: Global 30m v4.1

JAXA/ALOS/AW3D30/V4_1
Dataset Availability
2006-01-24T00:00:00Z–2011-05-12T00:00:00Z
Dataset Provider
Earth Engine Snippet
ee.ImageCollection("JAXA/ALOS/AW3D30/V4_1")
Tags
alos dem elevation elevation-topography geophysical jaxa topography

Description

ALOS World 3D - 30m (AW3D30) is a global digital surface model (DSM) dataset with a horizontal resolution of approximately 30 meters (1 arcsec mesh). The dataset is based on the DSM dataset (5-meter mesh version) of the World 3D Topographic Data. More details are available in the dataset documentation.

This ingested dataset combines data from versions 3.1, 4.0, and 4.1.

Version 4.1 (April 2024): This major update released 19,051 tiles covering global regions (excluding Antarctica and Japan). It incorporates new supplementary data for void filling and corrects partial anomalies found in versions 3.1 and 3.2, along with re-filling voids. For specific tile updates in v4.1, please use the v4.1 filter on map tiles or consult the latest format description.

Version 4.0 (April 2023): This update released 1,886 tiles, improving low and mid-latitude regions and areas south of 60 degrees latitude.

Key changes include: 1. New supplementary data for void filling. 2. Correction of partial anomalies and re-filling of voids (2 tiles). 3. Updated coastlines for regions south of 60 degrees latitude (44 tiles). 4. Disabled Caspian Sea water mask and supplemented with elevation data (54 tiles). 5. Extracted and corrected new partial anomaly areas in South America (1,786 tiles). 6. For detailed tile information for v4.0, please use the v4.0 filter on map tiles or refer to the format description.

Version 3.2, released in January 2021, is an improved version created by reconsidering the format in the high latitude area, auxiliary data, and processing method. Different pixel spacing for each latitude zone was adopted at high latitude area. Coastline data, which is one of the auxiliary datasets, was changed, and new supplementary data was used. In addition, as a source data for Japan, AW3D version 3 was also used. Furthermore, the method of detecting anomalous values in the process was improved.

The AW3D DSM elevation is calculated by an image matching process that uses a stereo pair of optical images. Clouds, snow, and ice are automatically identified during processing and applied the mask information. However, mismatched points sometimes remain especially surrounding (or at the edges of) clouds, snow, and ice areas, which cause some height errors in the final DSM.

Bands

Pixel Size
30 meters

Bands

Name Min Max Pixel Size Description
DSM -433* 8768* meters

Height above sea level. Signed 16 bits. Elevation (in meter) converted from the ellipsoidal height based on ITRF97 and GRS80, using EGM96†1 geoid model.
STK 1* 54* meters

Stacking number of the scene unit DSM used in producing DSM. The band is derived by resampling the stacking number for 5m resolution DSM to 30m resolution.
MSK meters

8-bit mask for the band.
* estimated min or max value

Terms of Use

Terms of Use

This dataset is available to use with no charge under the conditions specified in the Terms of use for ALOS Global Digital Surface Model.

Citations

Citations:
  • T. Tadono, H. Ishida, F. Oda, S. Naito, K. Minakawa, H. Iwamoto
    Precise Global DEM Generation By ALOS PRISM, ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol.II-4, pp.71-76, 2014. PDF file

  • J. Takaku, T. Tadono, K. Tsutsui : Generation of High Resolution Global DSM from ALOS PRISM, The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol. XL-4, pp.243-248, ISPRS, 2014. PDF file

  • J. Takaku, T. Tadono, K. Tsutsui, M. Ichikawa : Validation of 'AW3D' Global DSM Generated from ALOS PRISM, ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol.III-4, pp.25-31, 2016. PDF file

  • T. Tadono, H. Nagai, H. Ishida, F. Oda, S. Naito, K. Minakawa, H. Iwamoto : Initial Validation of the 30 m-mesh Global Digital Surface Model Generated by ALOS PRISM, The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, ISPRS, Vol. XLI-B4, pp.157-162, 2016. PDF file

  • J. Takaku, T. Tadono, M. Doutsu, F. Ohgushi, and H. Kai, : "Updates of 'AW3D30' ALOS Global Digital Surface Model in Antarctica with Other Open Access Datasets", Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIII-B4-2021, 401-408, 2021. PDF file

Explore with Earth Engine

Code Editor (JavaScript)

var dataset = ee.ImageCollection('JAXA/ALOS/AW3D30/V4_1');
var elevation = dataset.select('DSM');
var elevationVis = {
  min: 0,
  max: 5000,
  palette: ['0000ff', '00ffff', 'ffff00', 'ff0000', 'ffffff']
};
Map.setCenter(138.73, 35.36, 11);
Map.addLayer(elevation, elevationVis, 'Elevation');

// Reproject an image mosaic using a projection from one of the image tiles,
// rather than using the default projection returned by .mosaic().
var proj = elevation.first().select(0).projection();
var slopeReprojected = ee.Terrain.slope(elevation.mosaic()
                             .setDefaultProjection(proj));
Map.addLayer(slopeReprojected, {min: 0, max: 45}, 'Slope');
Open in Code Editor
ALOS World 3D - 30m (AW3D30) is a global digital surface model (DSM) dataset with a horizontal resolution of approximately 30 meters (1 arcsec mesh). The dataset is based on the DSM dataset (5-meter mesh version) of the World 3D Topographic Data. More details are available in the dataset documentation. …
JAXA/ALOS/AW3D30/V4_1, alos,dem,elevation,elevation-topography,geophysical,jaxa,topography
2006-01-24T00:00:00Z/2011-05-12T00:00:00Z
-90 -180 90 180
Google Earth Engine