Patent ID: RE43264

Claim:
A method of obtaining a localized nuclear magnetic resonance Nuclear Magnetic Resonance (NMR) signal from a sample a subsurface three dimensional (3D) volume in a static magnetic field using an array of two or more magnetic field transmitting coils, and an array of two or more magnetic field receiving coils, the method comprising: a) generating a single an alternating current excitation pulse on one or more transmitting coils , each of said transmitting coils of the array, providing a spatially distinct an inhomogeneous magnetic field in the three dimensional (3D) volume ; b) acquiring NMR signals on two or more magnetic field receiving coils of the array of magnetic field coils ; c) applying a plurality of excitation pulses to each transmitting coil or combination of transmitting coils, wherein each excitation pulse has a unique pulse moment defined as the product of the pulse amplitude and pulse length, and wherein the nth pulse moment PM(n) is not equal to (2n−1)*PM(1); and repeating steps a and b using a plurality of excitation pulses, wherein the plurality of excitation pulses produce magnetic fields in the 3D volume, wherein at least one excitation pulse is produced by a transmitting coil of the array that is spatially distinct from another transmitting coil geometry or location, and wherein at least one excitation pulse comprises a pulse moment that is unique from a pulse moment of another excitation pulse, and wherein an nth pulse moment PM(n) is not equal to (2n−1)*PM(1); and d) constructing a localized nuclear magnetic resonance NMR signal as a linear combination of NMR signals obtained using two or more transmitting coils or combinations of transmitting coils, two or more receiving coils, and two or more pulse moments for each transmitting coil excitation pulses corresponding to a plurality of different transmitting coil geometries or locations and a plurality of different pulse moments .