The Charles Stark Draper Laboratory, Inc.

Brian P Timmons

Rami S Mangoubi

Joseph M Kinast

Richard E Stoner

Philip S Babcock, Iv

Zachary R Hoffman

Sabrina Mansur

William Bonnice

Franklyn R Webb

Antonije Radojevic

A computer-implemented method is described for detecting, identifying and locating an object feature in a ferromagnetic object. At least one hardware processor executes program instructions to: define a planned scan trajectory for scanning the ferromagnetic object with a sensor array comprising a plurality of magnetometer sensors, measure magnetic fields of the ferromagnetic object with the sensor array along an actual scan trajectory at locations adjacent to the ferromagnetic material to produce object scanning data representing magnetic characteristics of the ferromagnetic object along the actual scan trajectory. The actual scan trajectory includes deviation motion of the scanning array from the planned scan trajectory. The deviation motion is then compensated for to identify and locate the object feature in the ferromagnetic object. The compensation includes adjusting the object scanning data for the deviation motion and/or using a feature model that reflects the deviation motion.

Scanning magnetometry motion compensation

A system and method using magnetic sensing to non-intrusively and non-destructively characterize ferromagnetic material within infrastructure. The system includes sensors for measuring magnetic field gradients from a standoff distance adjacent to ferromagnetic material. The method includes using the system to measure magnetic fields, determining magnetic field gradients measured by a sensor array, and comparing measured and modeled or historical magnetic field gradients at the same or similar positions to identify differences caused by a phenomenon in the ferromagnetic material, and, in a particular embodiment, to recognize defects and developing defects.

System and method for characterizing ferromagnetic material

Methods and apparatus for providing coherent atom population transfer using coherent laser beam pairs in which the frequency difference between the beams of a pair is swept over time. Certain examples include a Raman pulse adiabatic rapid passage sweep regimen configured to be used as a beamsplitter and combiner in conjunction with an adiabatic rapid passage mirror sweep or a standard Raman mirror pulse in a 3-pulse interferometer sequence.

Adiabatic rapid passage atomic beamsplitter using frequency-swept coherent laser beam pairs

Methods and apparatus that provide for precise and continuously-controlled generation of hyperfine polarizations and coherences in samples of laser cooled atoms. In one example, coherent population trapping induced by Raman pulses with preselected parameters (such as phase and duration) is employed as a mechanism for producing well-controlled atomic coherences and polarizations. In one example, these coherences and polarizations are used to provide precision polarization references for normalization of polarization readout measurements, and/or to provide precision phase references for phase storage or phase comparison.

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Milford, MA, United States of America

Brian P Timmons