Bibliography

Nighttime Enhancements in the Midlatitude Ionosphere and Their Relation to the Plasmasphere

In situ electron density measurements by the CHAllenging Minisatellite Payload and the Defense Meteorological Satellites Program F17 satellites show that the midlatitude ionization at altitudes of \~350 and 850\ km is enhanced in the late evening. The enhancements increase to maximum around midnight and are clearly observed till early morning as the equatorial ionization decays to minimal level. They appear in the winter hemisphere during June and December solstices and in both hemispheres during equinox. The enhancements are well confined between \textpm30\textdegree and \textpm50\textdegree magnetic latitude, with the magnetic flux tubes of L = 1.3 - 2.4 connecting to the plasmasphere. Furthermore, coincident longitudinal variations exist in both the ionospheric enhancements and the plasmaspheric total electron content, especially during the solstice months. The coincidence may suggest essential plasma transport between the ionosphere and the plasmasphere. These facts support the idea that the plasmasphere provides extra plasma to the midlatitude ionosphere through downward plasma influx along the magnetic field lines to form the nighttime ionization enhancements when the sunlight is absent.

Li, Quanhan; Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo;

Published by: Journal of Geophysical Research: Space Physics      Published on: 08/2018

YEAR: 2018     DOI: 10.1029/2018JA025422

Nighttime enhancement of midlatitude ionosphere and its connection to the plasmasphere

Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo; Li, Quanhan;

Published by: 42nd COSPAR Scientific Assembly      Published on:

YEAR: 2018     DOI:

Analysis and design of the ultraviolet warning optical system based on interference imaging

Ultraviolet warning technology is one of the important methods for missile warning. It provides a very effective way to detect the target for missile approaching alarm. With the development of modern technology, especially the development of information technology at high speed, the ultraviolet early warning system plays an increasingly important role. Compared to infrared warning, the ultraviolet warning has high efficiency and low false alarm rate. In the modern warfare, how to detect the threats earlier, prevent and reduce the attack of precision-guided missile has become a new challenge of missile warning technology. Because the ultraviolet warning technology has high environmental adaptability, the low false alarm rate, small volume and other advantages, in the military field applications it has been developed rapidly. For the ultraviolet warning system, the optimal working waveband is 250 nm ~280 nm (Solar Blind UV) due to the strong absorption of ozone layer. According to current application demands for solar blind ultraviolet detection and warning, this paper proposes ultraviolet warning optical system based on interference imaging, which covers solar blind ultraviolet (250nm-280nm) and dual field. This structure includes a primary optical system, an ultraviolet reflector array, an ultraviolet imaging system and an ultraviolet interference imaging system. It makes use of an ultraviolet beam-splitter to achieve the separation of two optical systems. According to the detector and the corresponding application needs of two visual field of the optical system, the calculation and optical system design were completed. After the design, the MTF of the two optical system is more than 0.8@39lp/mm.A single pixel energy concentration is greater than 80\%.

Wencong, Wang; Jin, Dong-dong; Chu, Xin-bo; Shi, Yu-feng; Song, Juan; Liu, Jin-sheng; Shao, Si-pei; Hu, Hui-jun; Xiao, Ting;

Published by:       Published on:

YEAR: 2017     DOI: 10.1117/12.2285832

A Method to Calculate the Ionospheric LBH Dayglow Emissions for Large Field of View

Yong-Chao, ZHANG; Fei, HE; Xiao-Xin, ZHANG; Bo, CHEN;

Published by: Chinese Journal of Geophysics      Published on:

YEAR: 2014     DOI:

Analyzing the hemispheric asymmetry in the thermospheric density response to geomagnetic storms

The thermospheric densities derived by CHAMP/STAR accelerometer within the time period from 01 May 2001 to 31 December 2007 are utilized to investigate the hemispheric asymmetry in response to strong storm driving conditions. The geomagnetic storms of 03\textendash07 April 2004 are first studied since the storms occurred close to the vernal equinox, allowing the seasonal asymmetry to be eliminated to the greatest extent. The averaged density enhancements in the southern polar region were much larger than that in the northern polar region. The comparisons of density versus Dst and Apindex indicate a strong linear dependence with the slopes of the fitted lines in the southern hemisphere being 50\% greater than that in the northern hemisphere. This effect can possibly be attributed to the non-symmetric geomagnetic field. 102 storm events are used to conduct a statistical analysis. For each storm, a linear fit is made between the averaged mass density and theDst and Ap indices independently in each hemisphere. The seasonal variation of the intercepts and the slopes of the fitted lines are further explored. The baseline is strongly dependent on season, with the hemisphere receiving the larger amount of sunlight having larger density. The slopes showed considerable hemispheric differences around the vernal equinox yet no statistical differences around other seasons. It is speculated that competing mechanisms cancel each other during the solstices, while during the equinoxes, the lower magnetic field in the southern hemisphere may allow stronger ion flows, thereby causing more Joule heating. It is uncertain why the vernal equinox would be favored in this explanation though.

Ercha, A.; Ridley, Aaron; Zhang, Donghe; Xiao, Zuo;

Published by: Journal of Geophysical Research      Published on: 08/2012

YEAR: 2012     DOI: 10.1029/2011JA017259

Geomagnetic storms; hemispheric asymmetry; thermospheric density

The seasonal dependence of cycle slip occurrence of GPS data over China low latitude region

The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip occurrence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the ionospheric irregularities over this region.

Zhang, Donghe; Feng, Man; Xiao, Zuo; Hao, Yongqiang; Shi, LiQin; Yang, GuangLin; Suo, YuCheng;

Published by: Science in China Series E: Technological Sciences      Published on:

YEAR: 2007     DOI: 10.1007/s11431-007-0059-4