ADEOS-II/AMSR L3 Snow Water Equivalent (1day,0.25deg) dataset is obtained from the AMSR sensor onboard ADEOS-II and produced by the Japan Aerospace Exploration Agency (JAXA).The Advanced Earth Observing Satellite-II (ADEOS-II) was launched on December 14, 2002 (Japanese Standard Time). The objective of ADEOS-II was to acquire data to contribute to international global climate change research, as well as for applications such as meteorology and fishery. ADEOS-II operation on orbit was given up on October 31 2003, because sufficient electric power was not available to maintain operation of the satellite.AMSR observes various physical contents concerning to water (H2O) by receiving weak microwaves naturally radiated from the Earth's surface and atmosphere and also regardless of day or night, the presence of clouds. Those sensors aim at collecting global data for mainly understanding the circulation of water and energy.Level 3 data inputs level 1B and level 2 data and projected to the map in accordance with the specified projection technique (Equi-Rectangular (EQR) or Polar Stereographic (PS)), and then averaged temporally and spatially. These statistical values are computed for observation data on ascending orbit and descending orbit respectively.This product includes daily mean Snow Water Equivalent (SWE). The 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.The provided format is HDF4. The current version of the product is "Version 7". The statistical period is 1 day.The projection method is EQR and PS. The generation unit is global.