Abstract: A blade monitoring system and method for a turbine assembly comprising rotating blades (14), the system comprising at least one sensor (10, 12) for transmitting a signal towards said rotating blades and detecting a time-varying return signal therefrom, and one or more processors (20) configured to calculate the time derivative of said return signal, generate a phase variation signal for said time derivative, determine minima points within said phase variation signal and measure said signal at said minima points so as to identify data representative of respective minimum path lengths, each said minimum path length corresponding to the returned signal as each respective blade passes said sensor, and generate, using said minimum path lengths, a time series of data representing the returned signal from individual blades as they pass the sensor.

Abstract: A method for suppressing the Jet Engine Modulation (JEM) clutter signal returns from compressor blades (26) in data sampled by a system for Foreign Object Debris (FOD) detection in the air intake (30) of a turbine assembly, the method comprising the steps of: (a) identifying in the data the start sample position and length in samples of a single complete shaft rotation; and (b) subtracting from a current rotation dataset the samples from a comparison rotation dataset corresponding to another complete single shaft rotation.

Abstract: A method for suppressing the Jet Engine Modulation (JEM) clutter signal returns from compressor blades (26) in data sampled by a system for Foreign Object Debris (FOD) detection in the air intake (30) of a turbine assembly, the method comprising the steps of: (a) identifying in the data the start sample position and length in samples of a single complete shaft rotation; and (b) subtracting from a current rotation dataset the samples from a comparison rotation dataset corresponding to another complete single shaft rotation.

Abstract: A blade monitoring system and method for a turbine assembly comprising rotating blades (14), the system comprising at least one sensor (10, 12) for transmitting a signal towards said rotating blades and detecting a time-varying return signal therefrom, and one or more processors (20) configured to calculate the time derivative of said return signal, generate a phase variation signal for said time derivative, determine minima points within said phase variation signal and measure said signal at said minima points so as to identify data representative of respective minimum path lengths, each said minimum path length corresponding to the returned signal as each respective blade passes said sensor, and generate, using said minimum path lengths, a time series of data representing the returned signal from individual blades as they pass the sensor.

Abstract: A dielectric loaded antenna, and method of designing same, for use in a high temperature environment, the antenna comprising an outer casing (14) of a material having a melting point of at least 1000° C., said outer casing (14) defining an inner channel, a first end of the channel defined by the casing defining a radiating aperture loaded with a section (Z4) of dielectric material of a first type which is chemically stable at a temperature of at least 1500° C., and a remaining length of said channel being loaded with sections (ZO-Z3) of at least one second type of dielectric material which is chemically stable at a temperature of at least 800° C., the dielectric constant of said first type of dielectric material being greater than that of the second type of dielectric material.