LaCoste and Romberg straight‐line gravity meter

Geophysics ◽  
1983 ◽  
Vol 48 (5) ◽  
pp. 606-610 ◽  
Author(s):  
Lucien LaCoste
Keyword(s):  
Cross Coupling ◽  
Coupling Effects ◽  
New Model ◽  
Silicone Fluid ◽  
Air Damping ◽  
Straight Line ◽  
New Instrument ◽  
Spring Suspension ◽  
Fluid Damping ◽  
Rough Handling

The LaCoste and Romberg straight‐line gravity meter uses a new suspension in which the movable element moves vertically in a straight line rather than in an arc of a circle (LaCoste, 1973a). It was designed primarily for shipboard operation to avoid effects from cross coupling between various ship accelerations, thereby making it unnecessary to correct for such effects. The straight‐line suspension is a modification of the zero length spring suspension used in all LaCoste and Romberg gravity meters. The new model also uses silicone fluid damping rather than the air damping used in earlier models. Its main advantages over the older models appear to be: it is (1) free of cross‐coupling effects, (2) easier to build and adjust, (3) less subject to slight degradation in performance from rough handling, and (4) less sensitive to ship vibrations. In spite of the above advantages it is doubtful whether the new model will give substantially better accuracy than the previous models, if the previous models are kept in good operating condition by making occasional crosscorrelation analyses (LaCoste, 1973b). Valliant (1983, this issue) describes sea tests of the new instrument.

Field trials with the LaCoste and Romberg straight‐line gravimeter

Geophysics ◽  
1983 ◽  
Vol 48 (5) ◽  
pp. 611-617 ◽  
Author(s):  
H. D. Valliant
Keyword(s):  
Correlation Analysis ◽  
Field Tests ◽  
Cross Coupling ◽  
Field Trials ◽  
Coupling Effects ◽  
Straight Line ◽  
Corrected Data ◽  
Correlation Techniques ◽  
The Cross

During field tests in 1980, the prototype of the LaCoste and Romberg straight‐line gravimeter (ser. no. SL-1) generally produced gravity values intermediate between those of two comparison “S” meters (ser. nos. S-56 and S-41). Correlation analysis shows that the data from SL-1 with no cross‐coupling correction are 15 percent smoother even in rough weather than the corrected data from either S meter. When corrections to the cross‐coupling effects are applied through postcruise correlation techniques, the curvature (degree of smoothness) of the respective data agrees to within 2 percent for each meter. These results verify that cross‐coupling errors have been virtually eliminated in the new gravimeter.

Aero-Propulsive and Propulsor Cross-Coupling Effects on a Distributed Propulsion System

2018 ◽  
Vol 55 (6) ◽  
pp. 2414-2426 ◽  
Author(s):  
Aaron T. Perry ◽  
Phillip J. Ansell ◽  
Michael F. Kerho
Keyword(s):  
Cross Coupling ◽  
Propulsion System ◽  
Coupling Effects ◽  
Distributed Propulsion

scholarly journals Yaw control torque generation for a hovering robotic hummingbird

2019 ◽  
Vol 16 (1) ◽  
pp. 172988141882396 ◽  
Author(s):  
Ali Roshanbin ◽  
André Preumont
Keyword(s):  
Control Mechanism ◽  
Cross Coupling ◽  
Parallel Mechanisms ◽  
Design Development ◽  
Control Torque ◽  
Coupling Effects ◽  
Flight Tests ◽  
Wing Kinematics ◽  
Yaw Control ◽  
Torque Generation

This study describes the design, development, and flight tests of a novel control mechanism to generate yaw control torque of a hovering robotic hummingbird (known as Colibri). The proposed method generates yaw torque by modifying the wing kinematics while minimizing its influence on roll and pitch torques. To achieve this, two different architectures of series and parallel mechanisms are investigated; they are mathematically analyzed to investigate their behavior with respect to cross-coupling effects. The analysis is verified by measuring the control torque characteristics. The efficacy of the proposed method is also explored by flight experiments.

New compact quad-passband bandpass filter based on multi-layer substrate technique

2014 ◽  
Vol 7 (6) ◽  
pp. 679-683
Author(s):  
Hung-Wei Wu ◽  
Shih-Hua Huang
Keyword(s):  
Bandpass Filter ◽  
Cross Coupling ◽  
Bottom Layer ◽  
The Other ◽  
Input Output ◽  
Coupling Effects ◽  
Layered Substrate ◽  
Stepped Impedance Resonator ◽  
Multi Mode

A new compact quad-passband bandpass filter (BPF) using multi-mode resonators (MMRs) based on multi-layered substrate technique is proposed. The filter consists of a pair of multi-mode resonators (uniform impedance resonator and stepped impedance resonator) operated at 1.8/3.7 GHz on top layer and the other pair of the multi-mode resonators operated at 2.4/3 GHz on bottom layer. Source–load coupling lines are used to be the input/output (I/O) ports for providing the multi-paths propagations by cross-coupling effects in the filter. Specifically, the operated frequencies of the filter at 1.8/2.4/3/3.7 GHz with bandwidths of 6.7, 8.2, 4.6, and 7.2% are successfully designed and implemented. The proposed filter is useful for the multi-passband filters design, especially when the passbands are needed to be very close.

An Improved Magnetic Circuit Model of a 3-DOF Magnetic Bearing Considering Leakage and Cross-Coupling Effects

2017 ◽  
Vol 53 (11) ◽  
pp. 1-6 ◽  
Author(s):  
Yunlong Zhong ◽  
Lijian Wu ◽  
Xiaoyan Huang ◽  
Youtong Fang ◽  
Jian Zhang
Keyword(s):  
Magnetic Circuit ◽  
Cross Coupling ◽  
Magnetic Bearing ◽  
Circuit Model ◽  
Coupling Effects
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