Results 61 to 70 of about 3,312 (202)
Simulation and Analysis of the Dynamic Range of the Lunar Radar and A New Algorithm for Surface Medium Electromagnetic Parameters Inversion [PDF]
, 2016 探地雷达(GPR)通过向地下发射高频率宽带电磁波来探测地下物体、地层界面以及地下介质属性和分布结构，被广泛应用于经济建设和军事各领域。由于雷达信号会受到各种电磁和背景噪声干扰，使得接收到的信号不能直接准确地反映地下介质信息，造成对目标检测和识别的困难。特别当处于非理想环境条件下，非目标介质反射信号干扰复杂，目标的反射波很难被识别。在对路面、隧道以及地下等检测时，遇到的地下介质多是层状分布的。人们不仅希望获得各层的深度和厚度，还希望得到各层介质的介电常数和电导率等参数。因此，本文将地表层介质作为研究的对象，
俞子伟
core
Politics &Policy, Volume 54, Issue 2, April 2026.ABSTRACT This study employs advocacy coalition framework (ACF) theory to analyze debates over U.S. space policies designed to avoid dangerous collisions between objects in Earth orbit. For decades, the Department of Defense prioritized national security in its development of space traffic coordination (STC) systems like the Space Surveillance Network ...
Jeffrey S. Lantis
wiley +1 more source
Restoration of seventeenth century water gardens at Bramham Park [PDF]
, 2003 Bramham Park, near Wetherby, is the only large-scale formal garden in the UK to survive virtually unchanged from the late seventeenth and early eighteenth centuries.
Holden, J.
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Monte Carlo Simulation of 3D Cloud Radiance Distributions Affected by Ground‐Based Lighting
Journal of Geophysical Research: Atmospheres, Volume 131, Issue 6, 28 March 2026.Abstract Satellite observations of artificial light sources at night are increasing. Clouds, as the most important radiative modulators in the Earth‐atmosphere system, significantly influence the observed values and spatial distribution of the artificial light coming from the ground.
Huixin Sun +3 more
wiley +1 more source
Radar Investigation of Mars, Mercury, and Titan [PDF]
, 1995 Radar astronomy is the study of the surfaces and near surfaces of Solar System objects using active transmission of modulated radio waves and the detection of the reflected energy.
Butler, Bryan J. +2 more
core +1 more source
Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.Abstract A polar cap patch was observed to exit the polar cap to become a blob as it entered the auroral oval on the nightside of the Earth under moderately quiet geomagnetic conditions (Kp = 3−). Auroral particle precipitation led to an increase in the electron density of the blob.
S. J. Maguire +9 more
wiley +1 more source
Revealing the Internal Structure of Mars‐Analog Glaciers From Drone‐Based Radar Sounding
Journal of Geophysical Research: Planets, Volume 131, Issue 3, March 2026.Abstract Martian debris‐covered glaciers (DCGs) contain large quantities of water ice beneath a protective layer of rock and dust. Properties of the overlying regolith such as density and depth to ice are critical parameters for guiding in situ resource utilization (ISRU) of water and coring missions targeting potential habitats.
Roberto J. Aguilar +4 more
wiley +1 more source
Remote Sensing, 2020 The Lunar Penetrating Radar (LPR) onboard the Yutu-2 rover from China’s Chang’E-4 (CE-4) mission is used to probe the subsurface structure and the near-surface stratigraphic structure of the lunar regolith on the farside of the Moon.
Hanjie Song +5 more
doaj +1 more source
Exploring the Interior Structure of (16) Psyche Through Basin‐Scale Collisions
Journal of Geophysical Research: Planets, Volume 131, Issue 3, March 2026.Abstract Asteroid (16) Psyche, the largest member of the M/X‐type asteroids, may be the leftover core of a differentiated planetesimal. As such (16) Psyche will be explored in detail by NASA's discovery‐class Psyche mission in 2029. This will be the first mission to orbit a metal‐rich asteroid, or any asteroid in the 100–500 km size range.
Namya Baijal +7 more
wiley +1 more source
Remote Sensing, 2019 Structural analysis of lunar regolith not only provides important information about lunar geology but also provides a reference for future lunar sample return missions.
Bin Hu +3 more
doaj +1 more source