Abstract: A radio frequency (RF) or other form of detector detects discharges of an insulated system which can occur when electrical insulation becomes wet, for subsequent analysis and decision processes. Additionally, for RF detection, a frequency selector can be used to select a “quiet” region of the discharge spectrum before demodulation and further analysis and decision. Finally, redundant sets of such filters avoid the need to continuously reconfigure the detection system.

Abstract: High frequency (HF) antennas for wideband signals are used in the tracking of railcars. These are rugged antennas especially adapted to the hostile environment of a railcar. One antenna is in the form of a magnetic loop. Another generates an electric field produced by a plate mounted just below the railcar undercarriage with an optional dielectric slab situated between the plate and the undercarriage. The antennas need not be specified in terms of optimal parameters since the approach taken is to provide a generic antenna structure adapted to being fitted underneath the carriage of a railcar. This generic structure exhibits a mitigated Q and is capable of broadband tuning. This feature makes the antenna easier and less costly to produce in large quantities and facilitates use of a standard fitting mechanism and installation procedure.

Abstract: An asymmetrical (inbound only) high frequency communication system for asset tracking is made up of a message preparation and transmitter subsystem, a receiving subsystem, and a system monitoring subsystem. A transmission channel is selected randomly or pseudorandomly. Prior to each transmission, the transmitter performs a radiometric measurement of a selected channel. If the measurement exceeds a predetermined threshold, transmission in the selected channel is canceled and another channel is selected. The transmission protocol achieves frequency diversity by sequentially transmitting a message on a plurality of different channels. The receiving subsystem has a plurality of spatially separated receiver sites at various geographical points, thereby providing spatial diversity. The receiver sites are linked to a common processing center. Onboard the asset and collocated with the transmitter, a system monitoring subsystem records and stores parameters related to the message preparation and transmitter subsystem.