Contactless recognition system for railway line distance markers - has reflectors along track which modulate reflected microwave beam with characteristic pulse sequences

摘要

The noncontacting recognition system is esp. for recognition of distance markers along a track from a railway engine. The markers are in the form of electromagnetic radiation reflectors, esp. microwave reflectors, connected to control circuits which continuously alter the terminating impedance of the reflectors with a characteristic pulse sequence for each of the latter. The engine carries a transceiver with an antenna which strokes the reflectors as the engine passes. The receiver has an analyser circuit with several search filters set to the various characteristic pulse sequences.