Abstract: Methods and apparatuses are described for determining the operating status of a turbine engine. An eddy current sensor is provided having a sensing field in communication with a plurality of rotating turbine blades during a revolution of a turbine engine. The sensor generates signature data for the passage of each blade. An analytic waveform is determined from the signature data and blade characteristic data is determined from the analytic waveform.

Abstract: A method and apparatus for determining the operating condition of a turbine engine. An eddy current sensor is provided having a sensing field in communication with a plurality of rotating turbine blades during a revolution of a turbine engine. A threshold point value is defined for the signature data. A plurality of positive threshold point pairs and negative threshold point pairs are identified. A plurality of positive threshold widths from a plurality of times elapsed between the positive threshold point pairs and a plurality of negative threshold widths from a plurality of times elapsed between the negative threshold point pairs are determined. A plurality of threshold ratios are determined from a plurality of pairs of positive and negative threshold widths. A variance of the threshold ratios is correlated with an operating condition of the turbine engine.

Abstract: Methods and apparatuses are described for determining the operating status of a turbine engine. An eddy current sensor is provided having a sensing field in communication with a plurality of rotating turbine blades during a revolution of a turbine engine. The sensor generates signature data for the passage of each blade. An analytic waveform is determined from the signature data and blade characteristic data is determined from the analytic waveform.

Abstract: A method and apparatus for determining the operating condition of a turbine engine. An eddy current sensor is provided having a sensing field in communication with a plurality of rotating turbine blades during a revolution of a turbine engine. A threshold point value is defined for the signature data. A plurality of positive threshold point pairs and negative threshold point pairs are identified. A plurality of positive threshold widths from a plurality of times elapsed between the positive threshold point pairs and a plurality of negative threshold widths from a plurality of times elapsed between the negative threshold point pairs are determined. A plurality of threshold ratios are determined from a plurality of pairs of positive and negative threshold widths. A variance of the threshold ratios is correlated with an operating condition of the turbine engine.

Abstract: WAM.TM. is a new method of digitally coding and decoding acoustic signals for data compression and noise reduction. The method comprises constructing a filter bank using wavelet transforms of a basic filter impulse function to represent the response of the mammalian cochlea. Data compression is obtained by truncation of a discrete representation. Reconstruction relies on the theory of frames and produces a reconstruction method and apparatus based on irregular sampling methods which produces good quality results in a very few stages. Actual reconstructions show very good data compression and noise reduction performance.