UNAVCO publicly broadcasts streaming GPS data from a subset of Plate Boundary Observatory (PBO) stations. Realtime 1Hz streams from selected PBO stations are available in BINEX, RTCM 2.3 and RTCM 3.1 formats via the Networked Transport of RTCM via Internet Protocol (NTRIP). See the "Instructions" link at right for information about accessing these streams.
BINEX is an open-source binary format that contains both standard GPS observable data and other metadata and data timeseries from the receiver. Streaming BINEX data can be translated to RINEX in real time using UNAVCO's teqc utility. The various RTCM formats are typically less comprehensive than BINEX, but RTCM is more common and is translated by most NTrip Client software.