What do the various levels of AMSR-E data represent?

There are five different levels of AMSR-E data, Level-0 through Level-4.

Level-0

Reconstructed, unprocessed instrument/payload data at full resolution; any and all communications artifacts, for example, synchronization frames, communications headers, and duplicate data removed.

Level-1A

Reconstructed, unprocessed instrument data at full resolution, time-referenced, and annotated with ancillary information, including radiometric and geometric calibration coefficients and georeferencing parameters. For example, platform ephemeris computed and appended but not applied to the Level-0 data.

Level-1B

Level-1A data that have been processed to sensor units. Not all instruments will have a Level-1B equivalent.

Level-2

Derived geophysical variables at the same resolution and location as the Level-1 source data.

Level-3

Derived geophysical variables mapped on uniform space-time grid scales, usually with some completeness and consistency.

Level-4

Model output or results from analyses of lower level data. For example, variables derived from multiple measurements.