ADEOS-II/AMSR L1A 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.The Level 1A product is extracted data in range of a half orbit between the South Pole and North Pole from level 0 data and stores the value of observed microwave radiation from the earth surface.This dataset includes digital count value (raw data) with the missing values filled with dummy data. Quality information and Land/Ocean flag are appended. For AMSR/AMSR-E, they correspond to digital numbers (DN) converted from instrument output voltages. Other necessary information for higher-level processing, including satellite attitudes and the instrument condition, is also included. Data are not map-projected, but stored in the swath format. (Not open to public)The provided format is HDF4. The current version of the product is "Version 3". The generation unit is scene (defined as a half orbit).