Patent ID: 8888052

Claim:
A railroad train detection system comprising: a train detection zone comprising a railroad track and further comprising a plurality of detection zone limits; a plurality of sensor devices positioned so that a railroad train on the railroad track passing through one of the plurality of detection zone limits is within sensing range of at least one of the plurality of sensor devices, wherein each sensor device comprises: a first anisotropic magnetoresistive (AMR) sensor configured to generate detection zone limit AMR waveform data representative of changes in a generally constant magnetic field environment due to the presence of a railroad train within a sensing range of the first AMR sensor; and signal processing apparatus comprising a first microprocessor coupled to a data transmitter, wherein the first microprocessor is configured to process detection zone limit AMR waveform data generated by the first AMR sensor to generate detection zone limit vehicle detection data and further wherein the data transmitter is configured to transmit detection zone limit vehicle detection data generated by the first microprocessor; and a control processor, wherein the control processor is configured to: receive detection zone limit vehicle detection data transmitted by the plurality of sensor devices; and determine whether a train is present in the train detection zone based on received detection zone limit vehicle detection data.