Abstract: An apparatus and method for decoding complementary coded irregular data streams including a missing pulse detector circuit. The missing pulse detector circuit includes electrical circuit components configured to receive first and second irregular data streams, and output a data stream corresponding to a valid input data stream only when the two received data streams are bit-for-bit complements of each other.

Abstract: Apparatus and methods for a grade crossing protection system include at least one camera providing surveillance of a grade crossing, the at least one camera coupled to a transmitter configured to transmit a signal that includes imagery of the grade crossing to a transceiver onboard a train. A display unit onboard the train is provided to allow the train operator to view the grade crossing. A control unit in communication with the transceiver is configured to monitor the received signal and, based upon a determined location of the train relative to the train crossing, issue a command to the train's brake system to reduce the speed of the train, or stop the train, before the train reaches the grade crossing.