Raw CPR fields from the even-format frame.
Raw CPR fields from the odd-format frame.
Which frame is more recent.
A position known to be within about 45 NM of the true position (typically the receiver's location).
The resolved position, or undefined if the two frames fall in different latitude zones.
Resolves an absolute position from a paired even and odd surface CPR frame (ADS-B BDS 0,6 - type codes 5-8), per DO-260B SS A.1.7.4. Surface CPR spans a 90 degree latitude zone (versus 360 degree for airborne) and is ambiguous across four longitude quadrants, so unlike the airborne pair decode, a reference position is required to resolve the correct hemisphere and quadrant - the receiver's own location is normally used.