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The purpose of these historical notes is to present the early history of the Jicamarca Radio Observatory (JRO), a research facility that has been conducting observations and studies of the equatorial ionosphere for more than 50 years. We have limited the scope of these notes to the period of the construction of the observatory and roughly the first decade of its operation. Specifically, this period corresponds to the directorships under Kenneth Bowles, Donald Farley, and Tor Hagfors and the first period of Ronald Woodman, i.e., the years between 1960 and 1974. Within this time frame, we will emphasize observational and instrumental developments which led to define the capabilities of the Jicamarca incoherent scatter (IS) radar to measure the different physical parameters of the ionosphere. At the same time, we partially cover the early history of the IS technique which has been used by many other observatories built since. We will also briefly mention the observatory's early and most important contributions to our understanding of the physical mechanisms behind the many peculiar phenomena that occur at the magnetic Equator. Finally, we will put special emphasis on the important developments of the instrument and its observing techniques that frame the capabilities of the radar at that time.

The electromagnetic scattering generated by agricultural tilled soils can be affected by a strong anisotropic component of the rough-surface profile. An accurate and reliable modeling of the normalized radar cross section, under both monostatic and bistatic geometries, is particularly important and desirable, especially for the correct estimation of the soil moisture content by means of satellite-based observations. In this paper, moving from the modeling so far proposed in the literature, we present and discuss a novel, more general (i.e., 2-D), spectral representation of an agricultural tilled soil, implementing a solution of the scattering based on the first-order small-slope approximation. Comparisons are given with a well-established model based on a 1-D representation of the soil correlation function, accounting for the radiation pattern of the illuminating antenna. The investigation gives new insight on the phenomenology of the bistatic scattering from the anisotropic soil, providing interesting information for the next generation of satellite missions, which foresees the possibility of launching companion satellites carrying aboard a passive receiver collecting the signal transmitted by active SAR-based platforms.

©2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. A sea ice detection algorithm developed using the U.K. TechDemoSat-1 (U.K. TDS-1) global navigation satellite systems (GNSSs)-reflectometry data over the Arctic and Antarctic regions is presented. It is based on measuring the similarity of the received GNSS reflected waveform or delay Doppler map (DDM) to the coherent reflection model waveform. Over the open ocean, the scattered signal has a diffusive, incoherent nature; it is described by the rough surface scattering model based on the geometric optics and the Gaussian statistics for the ocean surface slopes. Over sea ice and, in particular, newly formed sea ice, the scattered signal acquires a coherence, which is characteristic for a surface with large flat areas. In order to measure the similarity of the received waveform or DDM, to the coherent reflection model, three different estimators are presented: the normalized DDM average, the trailing edge slope (TES), and the matched filter approach. Here, a probabilistic study is presented based on a Bayesian approach using two different and independent ground-truth data sets. This approach allows one to thoroughly assess the performance of the estimators. The best results are achieved for both the TES and the matched filter approach with a probability of detection of 98.5%, a probability of false alarm of ~ 3.6%, and a probability of error of 2.5%. However, the matched filter approach is preferred due to its simplicity. Data from AMSR2 processed using the Arctic Radiation and Turbulence Interaction STudy Sea Ice algorithm and from an Special Sensor Microwave Imager/Sounder radiometer processed by Ocean and Sea Ice SAF have been used as ground truth. A pixel has been classified as a sea ice pixel if the sea ice concentration (SIC) in it was larger than 15%. The measurement of the SIC is also assessed in this paper, but the nature of the U.K. TDS-1 data (lack of calibrated data) does not allow to make any specific conclusions about the SIC.

An incoherent Thomson scattering diagnostic will be installed in the JT-60SA tokamak to measure electron temperature and electron density profiles. The target radial spatial resolution is 25 mm with 46 spatial channels. The accuracy in electron temperature and density is a few percent at ne = 7.5 × 1019 m-3, which is the expected value in the plasma core. This paper presents the designs of collection optics, fibers with their alignment system, and polychromators. The collection optics overcomes unique issues for superconducting fusion devices, i.e., limited design space, high-temperature measurements, and harsh radiation condition. When in several years the more performing plasma will generate intense nuclear radiation, the lens materials of the optics can be replaced by radiation resistant glasses without major changes in the lens holder. It will prevent transmission degradation and keep stable measurement accuracy.

In the present paper, we report the angle integrated coherent scattering cross sections of some elements at low momentum transfer over four angular ranges for some elements in the atomic number range 13 ≤ Z ≤ 82 for 241Am (59.54 keV) gamma rays. The coherent scattering cross sections were derived from the experimentally measured total (Coherent + incoherent) scattering cross sections for the elements at the energy of interest by subtracting separately the small contribution of the corresponding angle integrated incoherent scattering cross sections. The theoretical angle integrated incoherent scattering cross sections were computed by numerically integrating the values provided in the compilations based on the non-relativistic Hartree-Fock (NRHF) model and the modified form factor (MFF) model for the charge distribution within the atom. The present values of the angle integrated coherent scattering cross sections of the elements Al, Fe, Cu, Zn, Cd, Sn and Pb at 59.54 keV in the angular ranges of ( 0 ∘ − 4 ∘ ) , ( 0 ∘ − 6 ∘ ) , ( 0 ∘ − 8 ∘ ) and (0°–10°) so obtained are compared with the corresponding theoretical S-matrix data within the range of experimental errors. The root mean square error on the measured cross sections was found to be the lowest for Al at 4.1% and the highest for Pb at 4.9%. For the other elements the error was in between these two values. Possible conclusions are drawn based on the present study.

УДК 550.385.4, 550.358:550.388 Приведены результаты расчетов эффектов возмущений теплового и динамического режимов верхней атмосферы Земли во время сильной магнитной бури 13–14 ноября 2012 г. Магнитная буря вызвала целый комплекс процессов, сопутствовавших возмущениям плазмы, электрических и магнитных полей в различных областях околоземного пространства. Подтверждено наличие в геомагнитных бурях как индивидуальных особенностей, так и общих закономерностей. Ключевые слова: геокосмическая буря, ионосферное возмущение, некогерентное рассеяние, динамические и тепловые процессы Статья поступила в редакцию 01.10.2014 Radio phys. radio astron. 2014, 19(4): 336-347 СПИСОК ЛИТЕРАТУРЫ 1. Домнин И. Ф., Емельянов Л. Я., Кацко С. В., Черногор Л. Ф. Ионосферные эффекты геокосмической бури 13–14 ноября 2012 г. // Радиофизика и радиоастрономия. – 2014. – Т. 19, № 2. – С. 170–180. 2. Черногор Л. Ф., Домнин И. Ф. Физика геокосмических бурь. – Харьков: ХНУ имени В. Н. Каразина, 2014. – 408 с. 3. Черногор Л. Ф. Физика Земли, атмосферы и геокосмоса в свете системной парадигмы // Радиофизика и радиоастрономия. – 2003. – Т. 8, № 1. – С. 59–106. 4. Григоренко Е. И., Пазюра С. А., Таран В. И., Черногор Л. Ф., Черняев С.В. Динамические процессы в ионосфере во время сильнейшей магнитной бури 30–31 мая 2003 г. // Геомагнетизм и аэрономия. – 2005. – Т. 45, № 6. – С. 803–823. 5. Salah J. E. and Evans J. V. Measurements of thermospheric temperature by incoherent scatter radar. In: Space Research XIII. – Berlin: Academie – Verlag, 1973. – P. 268–286. 6. Picone J. M., Hedin A. E., Drob D. P., and Aikin A. C. NRLMSISE-00 empirical model of the atmosphere: Statistical comparisons and scientific issues // J. Geophys. Res. Space Phys. – 2002. – Vol. 107, Is. A12. – P. SIA15-1–SIA15-16. 7. Бэнкс П. М. Тепловая структура ионосферы // ТИИЭР. – 1969. – Т. 57, № 3. – С. 6–30. 8. Schunk R. W. and Nagy A. F. Ionospheres: Physics, Plasma Physics, and Chemistry. – Cambridge, UK: Cambridge University Press, 2004. – 554 p. 9. Banks P. M. Charged particle temperatures and electron thermal conductivity in the upper atmosphere // Ann. Geophys. – 1966. – Vol. 22. – P. 577–584. 10. Dalgarno A. and Degges T. C. Electron cooling in the upper atmosphere // Planet. Space Sci. – 1968. – Vol. 16, Is. 1. – P. 125–127. 11. Сергеенко Н. П. Оценки электрических полей во время ионосферных возмущений. В кн.: Ионосферное прогнозирование. – М.: Наука, 1982. – С. 91–96. 12. Брюнелли Б. Е., Намгаладзе А. А. Физика ионосферы. – М.: Наука, 1987. – 528 с. 13. Домнин И. Ф., Емельянов Л. Я., Ляшенко М. В., Харитонова С. В., Черногор Л. Ф. Ионосферные процессы, сопровождавшие геокосмическую бурю 5–6 августа 2011 г. // Радиофизика и радиоастрономия. – 2012. – Т. 17, № 4. – С. 320–332. 14. Григоренко Е. И., Лысенко В. Н., Таран В. И., Черногор Л. Ф. Результаты радиофизических исследований процессов в ионосфере, сопровождавших сильнейшую геомагнитную бурю 25 сентября 1998 г. // Успехи современной радиоэлектроники. – 2003. – № 9. – С. 57–94. 15. Григоренко Е. И., Лазоренко С. В., Таран В. И., Черногор Л. Ф. Волновые возмущения в ионосфере, сопровождающие вспышку на Солнце и сильнейшую магнитную бурю 25 сентября 1998 г. // Геомагнетизм и аэрономия. – 2003. – Т. 43, № 6. – С. 770–787. 16. Кацко С. В., Домнин И. Ф., Емельянов Л. Я., Ляшенко М. В., Черногор Л. Ф. Ионосферная буря 5–6 августа 2011 г.: результаты расчетов основных эффектов // Радиофизика и радиоастрономия. – 2014. – Т. 19, № 1. – С. 26–39. 17. Данилов А. Д. Реакция области F на геомагнитные возмущения (обзор) // Гелиогеофизические исследования. – 2013. – № 5. – С. 1–33. 18. Пазюра С. А., Таран В. И., Черногор Л. Ф. Особенности ионосферной бури 4–6 апреля 2006 г. // Космічна наука і технологія. – 2008. – Т. 14, № 1. – С. 65–76. 19. Mansilla G. A. Mid-latitude effects of a great geomagnetic storm // J. Atmos. Sol.-Terr. Phys. – 2004. – Vol. 66, No. 12. – P. 1085–1091. 20. Mansilla G. A. Some effects in the upper atmosphere during geomagnetic storms // Adv. Space Res. – 2010. – Vol. 47, No. 6. – P. 930–937. 21. Sojka J. J., David M., Schunk R. W., and Heelis R. A. A modeling study of the longitudinal dependence of storm time midlatitude dayside total electron content enhancements // J. Geophys. Res. Space. Phys. – 2012. – Vol. 117, Is. A2. – id. A017000.

We argue that the proton multiplicities measured in Roman pot detectors at an electron ion collider can be used to determine centrality classes in incoherent diffractive scattering. Incoherent diffraction probes the fluctuations in the interaction strengths of multi-parton Fock states in the nuclear wavefunctions. In particular, the saturation scale that characterizes this multi-parton dynamics is significantly larger in central events relative to minimum bias events. As an application, we study the centrality dependence of incoherent diffractive vector meson production. We identify an observable which is simultaneously very sensitive to centrality triggered parton fluctuations and insensitive to details of the model., Comment: 5 pages, 4 figures, RevTEX V2: small clarifications, to be published in PRL

It is known that for the study of low-energy gamma rays in the atmosphere, coherent scattering, incoherent scattering, photoelectric effect, and total coherent and incoherent cross-sections are needed. In this study, a number of interpolation functions are derived to relate energy to cross-section continuously.

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