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Sekine M. Ohatani S. Musha T. Irabu T. Kiuchi E. Hagisawa T. Tomita Y. 《IEEE transactions on aerospace and electronic systems》1982,(6):729-730
It is shown that the Weibull-distributed ground clutter obeys a Weibull distribution after processing by the double canceler moving target indicator (MTI). 相似文献
2.
Yoshinori Takano Hajime Yano Yasuhito Sekine Ryu Funase Ken Takai 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
Planetary protection has been recognized as one of the most important issues in sample return missions that may host certain living forms and biotic signatures in a returned sample. This paper proposes an initiative of sample capsule retrieval and onboard biosafety protocol in international waters for future biological and organic constituent missions to bring samples from possible habitable bodies in the solar system. We suggest the advantages of international waters being outside of national jurisdiction and active regions of human and traffic affairs on the condition that we accept the Outer Space Treaty. The scheme of onboard biological quarantine definitely reduces the potential risk of back-contamination of extraterrestrial materials to the Earth. 相似文献
3.
Karl-Heinz Glassmeier Jan Grosser Uli Auster Dragos Constantinescu Yasuhito Narita Stephan Stellmach 《Space Science Reviews》2007,132(2-4):511-527
Embedded in a large mass density and strong interplanetary magnetic field solar wind environment and equipped with a magnetic
field of minor strength, planet Mercury exhibits a small magnetosphere vulnerable to severe solar wind buffeting. This causes
large variations in the size of the magnetosphere and its associated currents. External fields are of far more importance
than in the terrestrial case and of a size comparable to any internal, dynamo-generated field. Induction effects in the planetary
interior, dominated by its huge core, are thought to play a much more prominent role in the Hermean magnetosphere compared
to any of its companions. Furthermore, the external fields may cause planetary dynamo amplification much as discussed for
the Galilean moons Io and Ganymede, but with the ambient field generated by the dynamo and its magnetic field-solar wind interaction. 相似文献
4.
Cancellation ratio limitations from raindrop properties in a perfectly circularly polarized radar system were found using a new raindrop size distribution which has an improved fit to the existing empirical data. Winds and multiple reflections between raindrops were not considered. 相似文献
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This viewpoint examines the likely reasons behind the renewed focus on international cooperation in the new US National Space Policy, noting that the rise of various Asian space powers is one factor. It demonstrates the increase in US-Asian space cooperation that is already underway, arguing that such cooperation can only be to the good in providing Asian countries with a greater degree of cutting-edge technology and know-how, as well as contributing to the overall safety and security of outer space. Nevertheless, there will doubtless be problems such as cost overruns and delays and effort will have to be applied if cooperation is to work. 相似文献
6.
Sekine M. Musha T. Tomita Y. Irabu T. 《IEEE transactions on aerospace and electronic systems》1978,(5):823-826
The parameters of the Weibull distribution and the threshold level for an adaptive CFAR detector are determined by calculating the mean value and the mean-squared value of the input signal voltage before it passes through a logarithmic amplifier. By using this threshold level an adaptive method for suppressing various VVeibull-distributed clutters is proposed. 相似文献
7.
Sekine M. Ohtani S. Musha T. Irabu T. Kiuchi E. Hagisawa T. Tomita Y. 《IEEE transactions on aerospace and electronic systems》1981,(4):596-598
Weibull-distributed ground clutter of cultivated land was measured using an L-band long-range air-route surveillance radar (ARSR) having a 3.0 ?s pulsewidth and a 1.23° beamwidth at very low grazing angles between 0.21° and 0.32°. It is shown that the shape parameter of the Weibull distribution varied from c = 1.507 to c = 2.0, corresponding to the Rayleigh distribution. 相似文献
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Sekine M. Musha T. Tomita Y. Hagisawa T. Irabu T. Kiuchi E. 《IEEE transactions on aerospace and electronic systems》1979,(6):824-830
Weather clutter was observed using an L band range (200nmi) air-route surveillance radar (ARSR). It is shown that the measured clutter amplitudes obey a Weibull distribution. 相似文献
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