Field Definitions are Available Here
Collection
string (80)
A brief description of the differences between this collection version and another collection version.
Improved radiometric calibration. Changes to ProductMetadata. Position_in_Orbit changed from float to double.
/VersionDescription
/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:abstract/gco:CharacterString
Descriptive Information (ECHO)