About AMSR

The Advanced Microwave Scanning Radiometer (AMSR) measures weak microwaves emitted from natural sources such as the earth's surface and atmosphere.

The development of microwave radiometers in Japan began in the 1970s. The first microwave radiometer was the Microwave Scanning Radiometer (MSR). It was launched in February 1987 aboard the ocean observing satellite MOS-1. Momo-1 ceased operations in November 1995 after observing data near Japan to confirm the sensor's functionality. In February 1990, its successor, MOS-1b, which had the same performance as MOS-1, was also launched.

Later, in 2002, two high-performance microwave radiometers were developed. One is AMSR-E on NASA's Aqua satellite (launched in May 2002), and the other is AMSR on JAXA's ADEOS-II satellite (launched in December 2002). The photo shows the exterior of AMSR-E at the test site.

The Advanced Microwave Scanning Radiometer 2 (AMSR2) onboard GCOM-W is currently in operation. AMSR3 is scheduled to be launched in FY2025.

AMSR Utilization

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.

Retrieval Algorithm

A method for retrieving physical quantities from observed brightness temperatures is called an algorithm. The algorithm for retrieving physical quantities for product generation was selected through an algorithm comparison and evaluation process in cooperation with the science team. After launch, we are continuously evaluating and improving the algorithm.

For algorithm details, please refer to the "Product Overview" for each product described in the AMSR Data Catalog