Determine the CE-1 lunar impact time with CDAS data

2009 ◽  
Author(s):  
Jintao Luo ◽  
Lan Chen ◽  
Yajun Wu ◽  
Xiuzhong Zhang
Keyword(s):  
Impact Time ◽  
Lunar Impact

scholarly journals Windblown Sand-Induced Degradation of Glass Panels in Curtain Walls

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Yuxi Zhao ◽  
Rongcheng Liu ◽  
Fan Yan ◽  
Dawei Zhang ◽  
Junjin Liu
Keyword(s):  
Visible Light ◽  
Mass Loss ◽  
Effective Area ◽  
Area Ratio ◽  
Light Transmittance ◽  
Relative Mass ◽  
Impact Time ◽  
Windblown Sand ◽  
Glass Panels ◽  
The Impact

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.

scholarly journals Three-Dimensional Fixed-Time Cooperative Guidance Law With Impact Angle Constraint and Prespecified Impact Time

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 29755-29763
Author(s):  
Mu Lin ◽  
Xiangjun Ding ◽  
Chunyan Wang ◽  
Li Liang ◽  
Jianan Wang
Keyword(s):  
Three Dimensional ◽  
Fixed Time ◽  
Impact Angle ◽  
Impact Time ◽  
Guidance Law ◽  
Cooperative Guidance ◽  
Impact Angle Constraint

Adjustable impact-time-control guidance law against non-maneuvering target under limited field of view

2021 ◽  
pp. 095441002110129
Author(s):  
Jun-Yong Lee ◽  
Hyeong-Guen Kim ◽  
H Jin Kim
Keyword(s):  
Field Of View ◽  
Control Technique ◽  
Moving Target ◽  
Time Error ◽  
Stationary Target ◽  
Impact Time ◽  
Maneuvering Target ◽  
Time Control ◽  
Guidance Law ◽  
Intercept Point

This article proposes an impact-time-control guidance law that can keep a non-maneuvering moving target in the seeker’s field of view (FOV). For a moving target, the missile calculates a predicted intercept point (PIP), designates the PIP as a new virtual stationary target, and flies to the PIP at the desired impact time. The main contribution of the article is that the guidance law is designed to always lock onto the moving target by adjusting the guidance gain. The guidance law for the purpose is based on the backstepping control technique and designed to regulate the defined impact time error. In this procedure, the desired look angle, which is a virtual control, is designed not to violate the FOV limit, and the actual look angle of the missile is kept within the FOV by tracking the desired look angle. To validate the performance of the guidance law, numerical simulation is conducted with different impact times. The result shows that the proposed guidance law intercepts the moving target at the desired impact time maintaining the target lock-on condition.

scholarly journals Spectral properties of lunar impact melt deposits from Moon Mineralogy Mapper (M3) data

Icarus ◽  
2021 ◽  
Vol 361 ◽  
pp. 114392
Author(s):  
C.D. Neish ◽  
K.M. Cannon ◽  
L.L. Tornabene ◽  
R.L. Flemming ◽  
M. Zanetti ◽  
...  
Keyword(s):  
Spectral Properties ◽  
Impact Melt ◽  
Moon Mineralogy Mapper ◽  
Lunar Impact
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