Antarctic Surface Reflectivity Measurements from the ANITA-3 and HiCal-1 Experiments
Antarctic Surface Reflectivity Measurements from the ANITA-3 and HiCal-1 Experiments
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ANITA-3 和 HiCal-1 实验的南极表面反射率测量
DOI：
10.1142/s2251171717400025
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
R. Young
中科院分区：
文献类型：
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作者：
P. Gorham;P. Allison;O. Banerjee;J. Beatty;K. Belov;D. Besson;W. Binns;V. Bugaev;P. Cao;C. Chen;P. Chen;J. Clem;A. Connolly;B. Dailey;P. Dasgupta;C. Deaconu;L. Cremonesi;P. Dowkontt;B. Fox;J. Gordon;B. Hill;R. Hupe;M. Israel;P. Jain;J. Kowalski;J. Lam;J. Learned;K. Liewer;T. Liu;S. Matsuno;C. Miki;M. Mottram;K. Mulrey;J. Nam;R. Nichol;A. Novikov;E. Oberla;S. Prohira;B. Rauch;A. Romero;B. Rotter;K. Ratzlaff;J. Russell;D. Saltzberg;D. Seckel;H. Schoorlemmer;S. Stafford;J. Stockham;M. Stockham;B. Strutt;K. Tatem;G. Varner;A. Vieregg;S. Wissel;F. Wu;R. Young
NASA赞助的ANITA项目的主要科学目标是测量超高能中微子和宇宙射线，这些超高能中微子和宇宙射线是通过中微子或宇宙射线与地球物质(例如大气或冰分子)相互作用产生的射频信号观察到的。要准确推断这些宇宙射线的能量，需要了解无线电波信号在冰-空气边界上的传输/反射。在过去的几十年里，使用同一位置的发射器和接收器对南极表面反射率进行的卫星测量或多或少是连续进行的。我们对四种不同的反射率测量进行了比较，频率从2 GHz到45 GHz，在接近正常入射的情况下，我们得到了大致一致的南极洲高反射率和低反射率随位置变化的地图。利用太阳作为射频源，ANITA-3气球载射频天线阵作为射频接收器，在12-30∘的仰角下，测量了200-1000 MHz范围内的地表反射率。与我们之前使用ANITA-2进行的测量一致，我们发现，在系统误差(主要是天线波束宽度不确定性)内以及在整个南极洲，与菲涅尔方程所规定的预期反射率符合得很好。为了探测南极太阳技术无法探测到的低入射角，以及以前的卫星探测没有探测到的低入射角，设计了一种新的实验方法(“HiCal-1”)。与以前的测量不同，HiCal-Anita构成了一个相隔数百公里的双基地发射器-接收器对。HiCal在200至600 MHz之间采集的数据显示，在该频段内，随着频率的变化，菲涅耳方程明显偏离菲涅耳方程，赤字随着入射倾角的增加而增加，我们将其归因于可能的表面粗糙度、表面颗粒效应、雷达杂波和/或地球曲率效应造成的反射区阴影的综合影响。我们讨论了HiCal结果的科学意义，以及HiCal-2计划的改进，为2016年12月发射做准备。
The primary science goal of the NASA-sponsored ANITA project is measurement of ultra-high energy neutrinos and cosmic rays, observed via radio-frequency signals resulting from a neutrino or cosmic ray interaction with terrestrial matter (e.g. atmospheric or ice molecules). Accurate inference of the energies of these cosmic rays requires understanding the transmission/reflection of radio wave signals across the ice–air boundary. Satellite-based measurements of Antarctic surface reflectivity, using a co-located transmitter and receiver, have been performed more-or-less continuously for the last few decades. Our comparison of four different reflectivity surveys, at frequencies ranging from 2 to 45GHz and at near-normal incidence, yield generally consistent maps of high versus low reflectivity, as a function of location, across Antarctica. Using the Sun as an RF source, and the ANITA-3 balloon borne radio-frequency antenna array as the RF receiver, we have also measured the surface reflectivity over the interval 200–1000MHz, at elevation angles of 12–30∘. Consistent with our previous measurement using ANITA-2, we find good agreement, within systematic errors (dominated by antenna beam width uncertainties) and across Antarctica, with the expected reflectivity as prescribed by the Fresnel equations. To probe low incidence angles, inaccessible to the Antarctic Solar technique and not probed by previous satellite surveys, a novel experimental approach (“HiCal-1”) was devised. Unlike previous measurements, HiCal-ANITA constitute a bi-static transmitter–receiver pair separated by hundreds of kilometers. Data taken with HiCal, between 200 and 600MHz shows a significant departure from the Fresnel equations, constant with frequency over that band, with the deficit increasing with obliquity of incidence, which we attribute to the combined effects of possible surface roughness, surface grain effects, radar clutter and/or shadowing of the reflection zone due to Earth curvature effects. We discuss the science implications of the HiCal results, as well as improvements planned for HiCal-2, preparing for launch in December 2016.
DOI：
10.1117/12.787446
发表时间：
2008-07
期刊：
--
影响因子：
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作者：
B. Crill;P. Ade;E. Battistelli;S. Benton;R. Bihary;J. Bock;J. Bock;J. Bond;J. Brevik;S. Bryan;C. Contaldi;O. Doré;M. Farhang;L. Fissel;S. Golwala;M. Halpern;G. Hilton;W. Holmes;V. Hristov;K. Irwin;W. Jones;W. Jones;C. Kuo;A. Lange;C. Lawrie;C. MacTavish;T. G. Martin;P. Mason;T. Montroy;C. Netterfield;E. Pascale;D. Riley;J. Ruhl;M. Runyan;A. Trangsrud;C. Tucker;A. Turner;M. Viero;D. Wiebe
通讯作者：
B. Crill;P. Ade;E. Battistelli;S. Benton;R. Bihary;J. Bock;J. Bock;J. Bond;J. Brevik;S. Bryan;C. Contaldi;O. Doré;M. Farhang;L. Fissel;S. Golwala;M. Halpern;G. Hilton;W. Holmes;V. Hristov;K. Irwin;W. Jones;W. Jones;C. Kuo;A. Lange;C. Lawrie;C. MacTavish;T. G. Martin;P. Mason;T. Montroy;C. Netterfield;E. Pascale;D. Riley;J. Ruhl;M. Runyan;A. Trangsrud;C. Tucker;A. Turner;M. Viero;D. Wiebe