Title :
Implementing procedures for improving proton precession frequency estimation
Author :
Ferreira, Heinrich J. ; Hancke, Gerhard P.
Author_Institution :
Dept. of Electr. & Electron. Eng., Pretoria Univ., South Africa
Abstract :
Introducing additional signal processing procedures, a significant improvement in accuracy has been achieved when applying the least-squares-error curve-fit algorithm previously described for frequency measurements on noisy sinusoidal signals with an exponential decay in amplitude. These techniques are especially powerful when used with the free-proton precession signal, which has the above mentioned characteristics. These procedures include weighing the zero-crossing measurements by appropriate factors in order to compensate for the exponential signal decay. Additionally, a hardware demodulation process is performed on the signal prior to detection, in order to enhance the quantification accuracy and further improve the accuracy
Keywords :
curve fitting; demodulation; frequency estimation; least squares approximations; magnetometers; proton detection; exponential signal decay; free-proton precession signal; hardware demodulation process; least-squares-error curve-fit algorithm; proton magnetometer sensor; proton precession frequency estimation; quantification accuracy; signal processing procedures; zero-crossing measurements; Clocks; Counting circuits; Demodulation; Frequency estimation; Frequency measurement; Hardware; Protons; Registers; Signal processing; Signal processing algorithms;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 1997. IMTC/97. Proceedings. Sensing, Processing, Networking., IEEE
Conference_Location :
Ottawa, Ont.
Print_ISBN :
0-7803-3747-6
DOI :
10.1109/IMTC.1997.603989