Committee on Data Management, Archiving, and Computing (CODMAC) Data Level Definitions

Level-0	Reconstructured unprocessed instrument/payload data at full resolution; raw engineering measurements
Level-1	Reconstructured unprocessed instrument data at full resolution, time-referenced, and annotated with ancillary information, computed and appended, but not applied, to the Level 0: processed tracking data
Level-2	Derived geophysical variables at the same resolution and location as the Level 1 source data.
Level-3	Variables mapped on uniform space-time grid scales, usually with some completeness and consistency. It is at this data level we will concentrate: examples include position time series, observation equations and normal equations from a single technology.
Level-4	Model output or results from analyses of lower level data (i.e., variables derived from multiple measurements)