Definition(en): Septentrio Binary Format (SBF) is the binary output format of Septentrio receivers, with data are arranged in binary blocks referred to as SBF blocks. Each block consists of a sequence of numeric or alphanumeric fields of different types and sizes. The total block size is always a multiple of 4 bytes. This format is used in conjunction with the Septentrio PolaRxS PRO GNSS receiver, that performs over multiple frequencies and constellations. It is used for ionospheric monitoring and space weather observations.