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Bistatic radar observations of the moon using the Clementine spacecraft and Deep Space Network.

机译：使用克莱门汀航天器和深空网络对月球进行双基地雷达观测。

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The author prepared, executed, and analyzed the data from a series of spotlight-mode bistatic radar (BSR) observations of the Moon's North and South Poles. The Ballistic Missile Defense Organization Clementine spacecraft served as an S-band transmitter, and 70-m antennas of the NASA/Deep Space Network received the reflections.; An average value of circular polarization ratio (CPR) for both poles of 0.344 (0.031 standard deviation) was found, but varied between 0.20 to 0.6 over small regions. The North Pole average CPR was 0.359 (0.0308 standard deviation). The South Pole average CPR was 0.333 (0.0238 standard deviation). By analyzing the CPR response versus bistatic angle, the author discovered a slight CPR enhancement approaching 1 dB (0.11 dB standard deviation) for Orbit 234 of the South Pole. This CPR enhancement could result from the coherent backscatter opposition effect (CBOE). Radar observable CBOE would be consistent with radar scattering from theoretically predicted, but never observed, ice accumulations. The beta-zero BSR track and CPR enhancement correlate with areas of permanent shadow within the South Pole-Aitken Basin and with high hydrogen accumulations reported by Lunar Prospector. The author found that BSR beta-zero radar tracks through periodically solar illuminated areas yielded no enhancements in his data.; The effect of angle of incidence on CPR for the South Pole was considered, and Orbit 234 was found to have a slightly elevated CPR compared to the other orbits.; Previous radar observations of the Moon employed earth-based monostatic radars or rudimentary orbiting bistatic techniques. These methods only used the quasi-specular (QS) reflection component of scattering.; This work is the first successful experiment to (a) collect data from lunar bistatic radar scattering using other than the dominant QS component, (b) use spotlight-mode bistatic radar technique outside of earth, and (c) return useful S-band bistatic scattering data from lunar polar regions, and (d) claim to detect slight radar enhancement for the South Pole using bistatic radar.; Previous radar studies reached inconclusive or negative results regarding ice [Stacy, 1993, Stacy, et al., 1997; Simpson et al., 1999]. Simpson found “weak suggestions of enhanced echoes at the time of South Pole backscatter” [Simpson et al., 1999], while Stacy found high reflectivity and high CPR (>1) areas near the pole [Stacy, 1993, Stacy, et al., 1997]. Simpson and Stacy chose to attribute their observed enhancements to diffuse scattering, but allow that ice scattering might exist.
机译：作者准备，执行和分析了来自月球南北两极的一系列聚光模式双基地雷达（BSR）观测数据。弹道导弹防御组织的Clementine航天器用作S波段发射机，NASA /深空网络的70米天线收到了反射。发现两极的圆极化率（CPR）平均值为0.344（标准偏差<0.031），但在小区域内变化范围为0.20至0.6。北极的平均CPR为0.359（<0.0308标准偏差）。南极平均CPR为0.333（<0.0238标准偏差）。通过分析CPR响应与双基地角的关系，作者发现南极轨道234的CPR略有提高，接近1 dB（标准偏差0.11 dB）。这种CPR增强可能来自相干反向散射对立效应（CBOE）。雷达可观测的CBOE与理论上预测但从未观察到的冰积聚与雷达散射相一致。 β零的BSR轨迹和CPR增强与南极艾特肯盆地内的永久阴影区域以及月球勘探者报告的高氢积累量有关。作者发现，BSR beta零雷达通过周期性的日光照射区域跟踪并没有增强他的数据。考虑到入射角对南极CPR的影响，并且发现234号轨道的CPR较其他轨道略高。以前对月球的雷达观测采用的是地基单基地雷达或基本轨道双基地技术。这些方法仅使用了散射的准镜面（QS）反射分量。这项工作是第一个成功的实验，它是（a）使用非主要QS分量从月球双基地雷达散射收集数据，（b）在地球外部使用聚光模式双基地雷达技术，并且（c）返回有用的S波段双基地（d）声称使用双基地雷达探测南极的雷达增强情况;先前的雷达研究在冰方面尚无定论或否定的结果[Stacy，1993； Stacy等，1997； Science等。 Simpson等，1999]。辛普森发现“在南极向后散射时增强回波的微弱建议” [Simpson等，1999]，而斯泰西发现极点附近具有高反射率和高CPR（> 1）区域[斯泰西，1993，斯泰西等。 （1997年）。辛普森（Simpson）和史泰西（Stacy）选择将他们观察到的增强归因于散射，但允许存在冰散射。

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