ALOS (Advanced Land Observing Satellite) is a Japanese earth observation satellite launched in 2006. The ALOS satellite carries three sensors: Panchromatic Remote Sensing Stereo Mapping (PRISM), which is mainly used for digital elevation mapping; Advanced Visible and Near-Infrared Radiometer-2 (AVNIR-2), which is used for precise land observation; phased array L-band Synthetic Aperture Radar (PALSAR) for all-weather, all-weather land observations. Preface – Artificial Intelligence Tutorial
ALOS-12.5m dem data comes from ALOS satellite phased array L-band synthetic aperture radar (PALSAR) collection, the sensor has three observation modes of high resolution, scanning synthetic aperture radar, and polarization. The horizontal and vertical accuracy of the data can reach 12.5 meters.
ALOS-12.5m DEM data is digital elevation model data acquired by the ALOS satellite of the Japan Aerospace Exploration Agency (JAXA), with a spatial resolution of 12.5m. The data covers a global scale, including land and sea. Among them, the land area data is divided into two versions: AW3D30 and AW3D30+.
The AW3D30 data was released in 2016 with a horizontal resolution of 30 meters and a vertical accuracy of 5 meters. The AW3D30+ data was released in 2019, with a horizontal resolution of 12.5 meters and a vertical accuracy of 2 meters. AW3D30+ data is processed and corrected with higher precision based on AW3D30 data.
The acquisition of ALOS-12.5m DEM data is carried out by the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) sensor of ALOS satellite. The sensor uses a three-line array camera to obtain high-resolution stereoscopic image data. Using these stereoscopic image data, digital elevation models can be generated.
ALOS-12.5m DEM data can be applied in many fields. For example, in terms of terrain analysis, the data can be used for terrain profile analysis, slope and aspect calculation, watershed analysis, etc.; Use this data to extract and simulate hydrological model parameters; in terms of natural resource management, you can use this data to classify land use, estimate vegetation coverage, etc.
The ALOS-12.5m DEM data can be downloaded free of charge from the JAXA website.
The scope of application of ALOS-12.5m DEM data includes:
- Terrain change monitoring: It can be used to monitor terrain changes caused by natural disasters such as landslides, mudslides, and earthquakes.
- Land use change monitoring: It can be used to monitor land use changes such as urban sprawl, deforestation, and farmland changes.
- Disaster risk assessment: It can be used to assess the impact of natural disasters such as earthquakes, floods, and typhoons on terrain and land use.
- Other applications: can be used for map making, 3D modeling, urban planning, etc.
ALOS-12.5m DEM data are valuable remote sensing data resources that can be used in a variety of applications.
Dataset ID: 
THEM/ALSO_THE_1
Time frame: 2011-2011
Scope: nationwide
Source: NASA
Copy code snippet:
var images = pie.ImageCollection("DEM/ALOS_DEM_12")
Band information:
| name | type | Resolution (m) | invalid value | coverage |
|---|---|---|---|---|
| elevation | int16 | 12.5 | -32767 | across China |
Attributes:
| date |
string |
image date |
code:
/**
* @File : ALOS_DEM
* @Time : 2020/7/21
* @Author : piesat
* @Version : 1.0
* @Contact : 400-890-0662
* @License : (C)Copyright 航天宏图信息技术股份有限公司
* @Desc : 加载ALOS DEM数据
*/
//加载ALOS DEM数据
var alos = pie.ImageCollection('DEM/ALOS_DEM_12')
.select("elevation")
.mean();
print(alos);
//定位地图中心
Map.centerObject(alos, 2)
//加载显示数据
Map.addLayer(alos, {min:0, max:3000, palette: ['000000', '023858', '006837', '1a9850',
'66bd63', 'a6d96a', 'd9ef8b', 'ffffbf',
'fee08b', 'fdae61', 'f46d43', 'd73027']}, "alos");