One or more unique variables within a data file that show what data quality assessments have been performed as well as diagnostics on various aspects of quality. A quality flag can be a byte value with each bit representing a pre-defined quality verification criterion provided as a Boolean expression.

1. A quality indicator shall provide sufficient information to allow all users to readily evaluate the “fitness for purpose” of the data or derived product. A Quality Indicator may be a number, set of numbers, graph, uncertainty budget, or a simple “flag”.
2. One or more unique variables within a data file whose numerical value shows the overall quality of a geophysical measurement. The numerical value should be on a predefined numerical scale. For example, uncertainty per pixel (or measurement), percent cloud cover (in a scene).

Secondary data required to assess the primary data set’s fitness for purpose, e.g. calibration and validation data and quality control results.

A data product, usually related to a Level 1 or higher Standard Data Product, which is generated and distributed in near-real time.