Developments in SQUID-based technology have enabled direct measurement of magnetic tensor data for geophysical exploration. For quantitative interpretation, we introduce 3D regularized inversion for magnetic tensor data. For mineral exploration-scale targets, our model studies show that magnetic tensor data have significantly improved resolution compared to magnetic vector data for the same mod...

In clinical decision making, (semi-)automatic unsupervised classification of data for diagnostic purposes is becoming more and more important. This paper describes the application of mixture modelling, a clustering where multivariate Gaussians are used to describe clusters in the data, to in vivo nuclear magnetic resonance data of patients with brain tumours. Images as well as localized spectra...

Probability theory is applied to the problem of estimating the amplitudes of the sinusoids in nuclear magnetic resonance data containing two exponentially decaying sinusoids. The posterior probability-density of one of the amplitudes is derived independent of the phases, frequencies, decay-rate constants, variance of the noise, and the amplitude of the other sinusoid. This probability-density f...

Model variograms describe the space domain statistics of magnetic and gravity data. Variogram analysis can be used to map intensity, depth, and scaling exponent (self-correlation) of source. In previous statistical methods the measured data were gridded and transformed to the wavenumber domain; then their power spectrum was analyzed using a spectral model. To avoid the loss and distortion of in...

In this paper, we discuss several aspects of data organization in the framework of a recently developed magnetic bubble memory technology known as a bubble lattice file. A dynamic ordering scheme, different from those implemented in conventional T-I bar bubble memories, is proposed. This ordering is particularly suited for bubble lattices. Some performance figures are included for comparison. I...

When a sensor coil is placed in the field of an electromagnetic transmitter, a voltage is induced and may be measured. The amplitude of this voltage depends on the distance from the transmitter and the angle between the axes of the transmitter and the sensor. This relationship between the state of the coil and the voltages, known as the dipole model, can be exploited to track sensor coils in th...

Acknowledgements: We would like to thank Seagate for funding this project through the Data Storage Systems Center at CMU. We also thank the members and companies of the PDL Consortium (including Abstract Modern Hard Disk Drives (HDDs) are fast approaching the superparamagnetic limit forcing the storage industry to look for innovative ways to transition from traditional magnetic recording to Hea...

Currently there are no UXO discrimination techniques based on total-field magnetic sensor data that rely on multipole expansion parameters of higher order than the dipole. In some cases, however, it can be advantages to describe a UXO target with both dipole and quadrupole parameters. In this paper, we examine the properties of the quadrupole moment and illustrate them using a synthetic example...