The ADS-B version this message was encoded to (0, 1, or 2 in practice). Gates whether nicBaro/silSupplementPerHour are populated, and how capabilityClassCode/operationalModeCode should be interpreted.
Raw 16-bit Capability Class Code field. Its sub-field breakdown depends on both surface and adsbVersion; not decoded further by this package - see RTCA DO-260B section 2.2.3.2.7.2.1 (or DO-260/DO-260A for earlier versions).
Heading/track reference direction.
Navigation Accuracy Category for Position, 0-15 (higher is more accurate).
Whether the reported altitude source meets the Navigation Integrity Category barometric requirement. Only populated for an airborne report on ADS-B version 1 or 2 - undefined otherwise (version 0 has no defined meaning for this bit, and surface reports do not carry it).
Navigation Integrity Category Supplement-A.
Raw 16-bit Operational Mode Code field. Its sub-field breakdown depends on both surface and adsbVersion; not decoded further by this package - see RTCA DO-260B section 2.2.3.2.7.2.2 (or DO-260/DO-260A for earlier versions).
Whether the Source Integrity Level is based on a per-hour probability (true) rather than a per-sample probability (false). Only populated on ADS-B version 2 - undefined otherwise.
Source Integrity Level, 0-3 (higher is more reliable).
Whether this report describes a surface (on-ground) aircraft, from the 3-bit subtype field (1 = surface; only 0 and 1 are defined, so anything else reports as false).
Decoded ADS-B Aircraft Operational Status (BDS 6,5, type code 31) - capability/operational mode codes, ADS-B version, and navigation integrity/accuracy fields, per RTCA DO-260B section 2.2.3.2.7.2.