A near-real-time instrument for wideband magnetic field monitoring with simultaneous time and frequency localization by multiresolution filter bank

The project described in this dissertation uses digital multiresolution filtering, a generalization of orthonormal wavelet theory, in a portable instrument to measure extreme- ly broadband ambient radiated magnetic fields. The four- teen-octave coverage is significantly wider than the cover- age typical of conventional broadband electromagnetic monitoring devices. Conventional instruments impose a choice, providing sharp frequency resolution at the cost of time localization, or good time localization at the sacrifice of all frequency information. The Magnetic Spectral Receiver (MSR) is the first electromagnetic field monitoring instru- ment to use multirate principles to obtain simultaneous time and frequency localization. It has been successfully de- ployed in several nuclear powerplant control rooms.

The processing circuit uses a parallel pipeline to implement a fourteen-level wavelet transform. In addition to its utility as the processing engine in the MSR, the circuit can serve as a processing engine for other applications needing a fast wavelet or multirate filter bank. It can be reprogrammed for various instrumentation applications that require either extreme broadband coverage or a fast wavelet transform implemented in hardware.