AMSUs are 20 channel instruments that consist of two sub-instruments, AMSU-A and AMSU-B. AMSU-A is a 15 channel instrument that takes measurements between 23.8 and 89 GHz. AMSU-B is an is a 5 channel instrument that takes measurements between 89 and 183.3 GHz.
An AMSU instrument has a swath of 1650 km. Its spatial resolution, broken down by sub-instrument is 45 km horizontal at nadir for AMSU-A and 15 km at nadir for AMSU-B.
Many different types of data is produced by AMSU instruments. They can produce their own data products, but often offers data as part of a blended product with other instruments:
- Level 1: brightness temperature
- Level 2: temperature, water vapor, cloud and ice measurements
- Level 2 blended: temperature, water vapor, ozone and cloud property measurements
Each AMSU instrument that flies on the Aqua, NOAA, or MetOp instruments is calibrated differently. More information about scan biases is available in the Microwave Sounder Scan Bias Analysis from AIRS/AMSU Observations (Power Point, 7.25 MB) document.