Results 161 to 170 of about 9,249 (208)

Two-Dimensional Gradiometer

Japanese Journal of Applied Physics, 2007
We developed a two-dimensional gradiometer that detects the gradient of a magnetic field in two orthogonal directions to measure the biomagnetic signal in an unshielded environment. We based the gradiometer on a low-Tc superconducting quantum interference device (SQUID) and wire-wound pickup coil.
Yusuke Seki, Akihiko Kandori
openaire   +1 more source

Spatial discrimination in SQUID gradiometers and 3rd order gradiometer performance

Canadian Journal of Physics, 1982
A detailed description of SQUID gradiometers is presented with the aim of improving their near field detection response while operating in unshielded, magnetically harsh urban environments. Spatial gradiometers of various orders are compared (0th, 1st, 2nd.
J. Vrba, A. A. Fife, M. B. Burbank, H. Weinberg, P. A. Brickett   +4 more
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Superconducting thin-film gradiometer

Journal of Applied Physics, 1978
We describe the design, fabrication, and performance of planar thin-film dc SQUID’s and planar gradiometers in which a dc SQUID is incorporated as a null detector. Each gradiometer was fabricated on a planar substrate and measured an off-diagonal component of changes in the magnetic field gradient.
Mark B. Ketchen, Wolfgang M. Goubau, John Clarke, Gordon B. Donaldson   +3 more
openaire   +1 more source

Gravity gradiometer survey errors

GEOPHYSICS, 1988
Gradiometer system noise, sampling effects, downward continuation, and limited data extent are the important contributors to moving‐base gravity gradiometer survey error. We apply a two‐dimensional frequency‐domain approach in simulations of several sets of airborne survey conditions to assess the significance of the first two sources. A special error
Steven J. Brzezowski, Warren G. Heller
openaire   +1 more source

Single layer YBaCuO-gradiometer

IEEE Transactions on Appiled Superconductivity, 1995
A single layer YBaCuO-gradiometer galvanically coupled to DC-SQUIDs were prepared on bicrystal substrates. The devices were operated at 77 K without any shielding. The best performance obtained was a field gradient resolution of 0.5 pT/cm/spl radic/(Hz) for a device with a baseline of 7 mm and a pickup-area of 2 cm/sup 2/. >
G.M. Daalmans, L. Bar, M. Kuhnl, D. Uhl, M. Selent, J. Ramos   +5 more
openaire   +1 more source

Advancing RF Quantum Gradiometers

2022
Here we have demonstrated the advancement of radio-frequency (RF) quantum gradiometersalong multiple fronts, namely in magnetic field sensitivity and interference suppression. We have pushed the sensitivity down to the quantum noise limits, achieving sub-fT/√Hz sensitivity, while retaining the ability to suppress large background interference.
openaire   +1 more source

GOCE gradiometer data calibration

Journal of Geodesy, 2019
The GOCE mission provides a unique gravity gradient dataset, which is used by most state-of-the-art global gravity field models. The quality of the gravity gradients of previous data releases degraded during the mission lifetime, which was often attributed to the increasing drag forces towards the end of the mission due to the approaching solar maximum
Christian Siemes, Moritz Rexer, Anja Schlicht, Roger Haagmans   +3 more
openaire   +2 more sources

SQUID gradiometers for archaeometry

Superconductor Science and Technology, 2001
The mapping of the Earth's magnetic field or field gradient is a proven method in surface exploration and archaeometry. Caesium vapour magnetometers show the best magnetic field resolution of commercial devices, but their sampling frequency is limited to 10 Hz.
Andreas Chwala, Ronny Stolz, Rob IJsselsteijn, Volkmar Schultze, Nikolay Ukhansky, Hans-Georg Meyer, Tim Schüler   +6 more
openaire   +1 more source

Superconducting tensor gravity gradiometer

Journal of Geodesy, 1981
A sensitive gravity gradiometer can provide much needed gravity data of the earth and improve the accuracy of inertial navigation. A complete determination of all five independent components of the gravity gradient tensor is possible in principle by rotating a single in-line component gradiometer.
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Aeromagnetic Gradiometers-a Perspective

Exploration Geophysics, 1995
Measurements of horizontal or vertical gradients of the magnetic field intensity can add a new dimension to high resolution aeromagnetic surveys of shallow basement areas. Although a number of vertical, horizontal and triaxial aeromagnetic gradiometers are in operation throughout the world, very little has been documented on the relative merits of ...
D. R. Cowan, M. Baigent, S. Cowan
openaire   +1 more source