About AMSR

AMSR-E
The Advanced Microwave Scanning Radiometer 2 (AMSR2) onboard the GCOM-W satellite is a remote sensing instrument for measuring weak microwave emission from the surface and the atmosphere of the Earth. From about 700 km above the Earth, AMSR2 will provide us highly accurate measurements of the intensity of microwave emission and scattering.
The antenna of AMSR2 rotates once per 1.5 seconds and obtains data over a 1450 km swath. This conical scan mechanism enables AMSR2 to acquire a set of daytime and nighttime data with more than 99% coverage of the Earth every 2 days.
Satellites in operation or under development
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The Global Observing SATellite for Greenhouse gases and Water cycle
GOSAT-GW / AMSR3
The Advanced Microwave Scanning Radiometer 3 (AMSR3) is the JAXA satellite/sensor currently under development.
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About Global Change Observation Mission - Water
"SHIZUKU" (GCOM-W)
Observing All Environmental Changes on Earth for Present and Future Generations
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"Aqua" Earth Observation Satellite
AMSR-E
An Earth-observation satellite to contribute to the understanding of the Earth's water cycle
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Advanced Earth Observation Satellite-II "Midori II"
ADEOS-II
The successor of the Advanced Earth Observing Satellite "Midori"(ADEOS) launched in 1996, is also known as Midori II.
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Marine Observation Satellite-1 "Momo-1" (MOS-1)
MOS-1/MSR, MOS-1b/MSR
It was developed as the first Earth observation satellite using Japan's own technology, in response to the need for effective use of Earth resources and environmental conservation.
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Quick Guide to AMSR
Enjoy AMSR!
Let's Make Paper Craft
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EOS Aqua 1/50 Scale Model
Satellite EOS Aqua
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About Microwave Remote Sensing
Water exists in the natural world in various forms and states, such as clouds, water vapor, and rain in the atmosphere, seawater and sea ice, rivers, soil, vegetation, and snow cover, and circulates with energy exchange. The water molecule H2O, which plays a key role in such water cycle, has a unique property in the microwave band and emits weak microwaves depending on its state, shape, and temperature. AMSR measures such weak microwave signals emitted from the natural world.

Microwave Radiation Transfer
Microwaves emitted from the earth's surface are absorbed and scattered by rain, clouds, and water vapor as they pass through the atmosphere, and are attenuated. At the same time, microwaves are also emitted from rain, clouds, and water vapor. There are also a few microwaves that are scattered by raindrops and cloud particles to the direction of the AMSR from other directions. This process of microwave propagation is called radiative transfer.

Frequency Characteristics
In the microwave radiative transfer, whether the signal from the atmosphere or from the earth's surface is dominant depends on the frequency band. In general, the surface signal is dominant in the lower frequency bands, while the atmospheric signal is dominant in the higher frequency bands. AMSR has two channels, horizontally polarization and vertically polarization, in each band from 6 GHz low frequency to 89 GHz high frequency. AMSR's multi-frequency and multi-polarization observation data can be used to estimate various water-related meteorological and hydrological quantities, such as rain and water vapor, seawater and sea ice, soil moisture and snow cover.

Microwave Radiometers in the Wold
Microwave radiometers have been launched by meteorological and satellite agencies around the world.
The size of the footprint and the observation width of a microwave radiometer are determined by the size of the antenna and other specifications, as well as the altitude of the satellite. The following graph plots the microwave radiometers of each country in the space of the observation width (horizontal axis) and the footprint of the 36 GHz band (vertical axis). The upper right corner of the graph indicates that the sensor has the highest performance with both resolution and high frequency/wide area observation performance.
Retrieval Algorithm
Development and selection of retrieval algorithms for generating geophysical products are being conducted through the algorithm comparison study in cooperation with science team. The same procedure will be continued after launch as needed to improve the algorithm performance.