scholarly journals Use of Surface Motion Characteristics Determined by InSAR to Assess Peatland Condition

2020 ◽  
Vol 125 (1) ◽  
Author(s):  
Lubna Alshammari ◽  
Doreen S. Boyd ◽  
Andrew Sowter ◽  
Chris Marshall ◽  
Roxane Andersen ◽  
...  
Keyword(s):  
Surface Motion ◽  
Motion Characteristics

On the surface motion characteristics in a single layered half-space excited by bulk waves

2017 ◽  
Vol 228 (9) ◽  
pp. 3329-3344 ◽  
Author(s):  
Pankaj Kumar ◽  
Anirvan DasGupta ◽  
Ranjan Bhattacharyya
Keyword(s):  
Half Space ◽  
Surface Motion ◽  
Bulk Waves ◽  
Motion Characteristics ◽  
Layered Half Space

scholarly journals Multiscale Variability and the Comparison of Ground and Satellite Radar Based Measures of Peatland Surface Motion for Peatland Monitoring

2022 ◽  
Vol 14 (2) ◽  
pp. 336
Author(s):  
Chris Marshall ◽  
Henk Pieter Sterk ◽  
Peter J. Gilbert ◽  
Roxane Andersen ◽  
Andrew V. Bradley ◽  
...  
Keyword(s):  
Multiple Scales ◽  
Drought Event ◽  
Surface Motion ◽  
Number Of Factors ◽  
Ground Validation ◽  
Peat Surface ◽  
Satellite Radar ◽  
Motion Characteristics ◽  
Scale Motion ◽  
Climate Events

Peatland surface motion is highly diagnostic of peatland condition. Interferometric Synthetic Aperture Radar (InSAR) can measure this at the landscape scale but requires ground validation. This necessitates upscaling from point to areal measures (80 × 90 m) but is hampered by a lack of data regarding the spatial variability of peat surface motion characteristics. Using a nested precise leveling approach within two areas of upland and low-lying blanket peatland within the Flow Country, Scotland, we examine the multiscale variability of peat surface motion. We then compare this with InSAR timeseries data. We find that peat surface motion varies at multiple scales within blanket peatland with decreasing dynamism with height above the water table e.g., hummocks < lawn < hollows. This trend is dependent upon a number of factors including ecohydrology, pool size/density, peat density, and slope. At the site scale motion can be grouped into central, marginal, and upland peatlands with each showing characteristic amplitude, peak timing, and response to climate events. Ground measurements which incorporate local variability show good comparability with satellite radar derived timeseries. However, current limitations of phase unwrapping in interferometry means that during an extreme drought/event InSAR readings can only qualitatively replicate peat movement in the most dynamic parts of the peatland e.g., pool systems, quaking bog.

scholarly journals Influence of motion characteristics of dual stealth aircraft on monopulse radar performance

2020 ◽  
Vol 1676 ◽  
pp. 012222
Author(s):  
Lei Bao ◽  
Chun-yang Wang ◽  
Tao-dong ◽  
Juan Bai ◽  
Sheng-Jun Wei ◽  
...  
Keyword(s):  
Motion Characteristics

scholarly journals Research on Measurement Method of Parachute Scanning Platform Based on MEMS Device

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 402
Author(s):  
Ning Liu ◽  
Tianqi Tian ◽  
Zhong Su ◽  
Wenhao Qi
Keyword(s):  
Physical Simulation ◽  
Inertial Sensors ◽  
Rotational Velocity ◽  
Attitude Measurement ◽  
Matlab Simulation ◽  
Scanning Angle ◽  
Reduce Development Time ◽  
Motion Parameters ◽  
Motion Characteristics ◽  
Scanning Motion

This paper studies the measurement of motion parameters of a parachute scanning platform. The movement of a parachute scanning platform has fast rotational velocity and a complex attitude. Therefore, traditional measurement methods cannot measure the motion parameters accurately, and thus fail to satisfy the requirements for the measurement of parachute scanning platform motion parameters. In order to solve these problems, a method for measuring the motion parameters of a parachute scanning platform based on a combination of magnetic and inertial sensors is proposed in this paper. First, scanning motion characteristics of a parachute-terminal-sensitive projectile are analyzed. Next, a high-precision parachute scanning platform attitude measurement device is designed to obtain the data of magnetic and inertial sensors. Then the extended Kalman filter is used to filter and observe errors. The scanning angle, the scanning angle velocity, the falling velocity, and the 2D scanning attitude are obtained. Finally, the accuracy and feasibility of the algorithm are analyzed and validated by MATLAB simulation, semi-physical simulation, and airdrop experiments. The presented research results can provide helpful references for the design and analysis of parachute scanning platforms, which can reduce development time and cost.

A reciprocating permanent magnetic actuator for driving magnetic micro robots in fluids

2021 ◽  
pp. 095440622110145
Author(s):  
Chuan Qu ◽  
Yong-Chen Pei ◽  
Qing-Yuan Xin ◽  
Zhen-Xing Li ◽  
Long Xu
Keyword(s):  
Permanent Magnet ◽  
Analytical Calculation ◽  
Magnetic Actuator ◽  
Cross Sectional ◽  
Permanent Magnetic Actuator ◽  
Element Simulation ◽  
Micro Robot ◽  
Analytical Formulas ◽  
Motion Performance ◽  
Motion Characteristics

Magnetic-based driving applications are receiving increasing attention. This study proposed a novel reciprocating permanent magnetic actuator (PMA) to manipulate magnetic micro robots to impact and clear blockages inside fluid pipes in a linear path. The PMA consisted of a cylindrical permanent magnet and a crank slider structure. A straight pipe with a circular cross-sectional area was located in front of the actuator to study the driving performance of PMA. A micro permanent magnet with a cylinder shape was employed as a working robot for manipulation inside the pipe. Firstly, analytical formulas were derived to obtain the magnetic driving force acting on the micro robot and determine the most suitable magnet configuration. The finite element simulation verified the analytical calculation. The developed reciprocating PMA prototype was then introduced, and the PMA and micro robot’s motion performance was analysed. Lastly, preliminary experiments were carried out for evaluating the micro robot’s motion characteristics. Performance tests for different excitation frequencies, flow rates, viscosities, and axial distances, indicating that PMA could manipulate the magnetic micro robot inside the pipe. The results confirmed that the developed PMA could effectively drive the micro robot with the advantage of consecutive magnetic driving. Especially, the micro robot featured good flexibility, rapid response, and a simple structure, suggesting that this micro robot may play an important role in industrial and medical applications, such as blockage elimination and thrombus clearance.

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