Infers which "Enhanced Surveillance" Comm-B register(s) a DF20/21 MB
field plausibly holds, and decodes each. Unlike DF17/18's type-code-coded
ME field, a Comm-B MB field carries no self-declared register identifier
for BDS 4,0/5,0/6,0 - this package would rather report every plausible
candidate (via structural and range validation, matching pyModeS's own
approach to this exact ambiguity) than silently guess a single wrong
answer. In practice this is usually unambiguous; BDS 5,0 and 6,0 are the
pair most likely to both pass validation for the same bytes.
Infers which "Enhanced Surveillance" Comm-B register(s) a DF20/21 MB field plausibly holds, and decodes each. Unlike DF17/18's type-code-coded ME field, a Comm-B MB field carries no self-declared register identifier for BDS 4,0/5,0/6,0 - this package would rather report every plausible candidate (via structural and range validation, matching pyModeS's own approach to this exact ambiguity) than silently guess a single wrong answer. In practice this is usually unambiguous; BDS 5,0 and 6,0 are the pair most likely to both pass validation for the same bytes.