<gml:Envelope srsName="http://www.opengis.net/def/crs/OGC/1.3/CRS84"><gml:lowerCorner>-180.0 -90.0</gml:lowerCorner><gml:upperCorner>180.0 90.0</gml:upperCorner></gml:Envelope>
No constraints but users need to be registered with [the G-portal User Registration system](https://gportal.jaxa.jp/gpr/user/regist1?lang=en) to download files.
The user is entitled to use G-Portal data free of charge without any restrictions (including commercial use) except for the condition about acknowledgement of data credit as stipulated in G-portal terms of use 7.(2).Click [here](https://gportal.jaxa.jp/gpr/index/eula?lang=en) for detailed G-Portal data usage constrains.
Aqua/AMSR-E L2 Snow Water Equivalent dataset is obtained from the AMSR-E sensor onboard Aqua and produced by the Japan Aerospace Exploration Agency (JAXA). Aqua of NASA was launched on May 4th, 2002 in Sun-synchronous sub-recurrent Orbit. Aqua observes various kinds of physical phenomena related to water and energy circulation from space. Aqua data promoted the research activities for interactions between the atmosphere, oceans and lands, and their effects on climate changes. AMSR-E scans the Earth's surface by mechanically rotating the antenna and acquires radiance data of the Earth's surface. Each frequency band is monitored by vertical and horizontal polarized wave. It conically scans and keeps an angle of incidence on the earth surface (a nominal of 55 degrees) and accomplishes a swath width of about 1450 km. The AMSR-E reached its limit to maintain the antenna rotation speed necessary for regular observations, and the AMSR-E restarted its observation in slow rotation mode (2 rotations per minute) on December 4, 2012. However, the AMSR-E reached its limit to maintain the antenna rotation speed necessary for slow rotation mode and it automatically halted its observation and rotation on December 4, 2015. Level 2 product stores the Geophysical quantity from the brightness temperature of level 1 product. This product includes Snow Water Equivalent (SND). Compared with non-snow surfaces, therefore, a snowpack has a distinctive electromagnetic signature at frequencies above 25 GHz. When viewed using passive microwave radiometers from above the snowpack, the scattering of upwelling radiation depresses the brightness temperature of the snow at increasingly high frequencies. This scattering behavior of snow can be exploited to detect the presence of snow on the ground. Having detected the snow, it is then possible to estimate the snow depth of the pack using the degree of scattering. The physical quantity unit is cm. Also, the quality flag for each observation point (Pixel Data Quality) is stored. The provided format is HDF4. Spatial resolution is 10 km. The current version of the product is "Version 7". The generation unit is scene (defined as a half orbit).
EARTH SCIENCE>TERRESTRIAL HYDROSPHERE>SNOW/ICE