Development and calibration of the Moon-based EUV camera for Chang'e-3

Song, Kefei; Li, Zhaohui; Wu, Qingwen; Ni, Qin; Wang, Xiaodong; Xie, Jin-Jiang; Liu, Shijie; He, Liwen; He, Fei; Wang, Xiaoguang; Chen, Bin; Zhang, Hongji; Wang, Haifeng; Zheng, Xin; Shulin, E; Wang, Yongcheng; Yu, Tao; Sun, Lingling; Wang, Jinling; Wang, Zhi; Yang, Liang; Hu, Qinglong; Qiao, Ke; Wang, Zhong-Su; Xiao, Yang; Bao, Hai-Ming; Liu, Wenguang; Li, Zhe; Chen, Ya; Sun, Hui; Chen, Wen‐Chang

doi:10.1088/1674-4527/14/12/013

Cited by 22 publications

(18 citation statements)

References 9 publications

(10 reference statements)

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“…Based on the plasmaspheric images observed by the IMAGE EUV imager [ Sandel et al ., ] and the CE 3 EUVC instrument [ Chen et al ., ; He et al ., ], the plasmapause locations on the magnetic equatorial plane were reconstructed with the Minimum L Algorithm (MLA, see Appendix ). In total, 3579 and 378 plasmaspheric images were selected from IMAGE EUV from 2000 to 2002 and from CE 3 EUVC in 2014, respectively, and 48,899 plasmapause locations were obtained in 1 h MLT intervals.…”

Section: Methodsmentioning

confidence: 99%

A new solar wind‐driven global dynamic plasmapause model: 1. Database and statistics

Zhang

Ruan

et al. 2017

JGR Space Physics

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A large database, possibly the largest plasmapause location database, with 49,119 plasmapause crossing events from the in situ observations and 3957 plasmapause profiles (corresponding to 48,899 plasmapause locations in 1 h magnetic local time (MLT) intervals) from optical remote sensing from 1977 to 2015 by 18 satellites is compiled. The responses of the global plasmapause to solar wind and geomagnetic changes and the diurnal, seasonal, solar cycle variations of the plasmapause are investigated based on this database. It is found that the plasmapause shrinks toward the Earth globally and a clear bulge appears in the afternoon to premidnight MLT sector as the solar wind or geomagnetic conditions change from quiet to disturbed. The bulge is clearer during storm times or southward interplanetary magnetic field. The diurnal variations of the plasmapause are most probably the result of the difference between the magnetic dipole tilt and the Earth's spin axis. The seasonal variations of the plasmapause are characterized by equinox valleys and solstice peaks. It is also found that the plasmapause approaches the Earth during high solar activity and expands outward during low solar activity. This database will help us study and understand the evolution properties of the plasmapause shape and the interaction processes of the plasmasphere, the ring current, and the radiation belts in the magnetosphere.

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Section: Methodsmentioning

confidence: 99%

A new solar wind‐driven global dynamic plasmapause model: 1. Database and statistics

Zhang

Ruan

et al. 2017

JGR Space Physics

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“…It is suggested that, imaging at dawn or dusk on magnetic equatorial plane can reveal the latitudinal configurations of the bow shock, the magnetopause, the magnetosheath and the cusps in the magnetosphere, and imaging from the polar region can capture the longitudinal configurations of those structures. Of course, combined imaging from both equatorial and polar perspectives can obtain the three‐dimensional structures of the magnetosphere. The EUV emissions produced in the SWCX process in the magnetosheath for disturbed solar wind conditions could achieve or exceed 100 mR, the threshold of current remote sensing EUV imagers [ Sandel et al , ; He et al , ; Chen et al , ], near the plasmapause. Therefore, the SWCX EUV emissions in the magnetosheath for highly disturbed SW‐IMF conditions should be taken into consideration in processing the Moon‐based plasmaspheric EUV images and image inversions. It can be inferred from the simulations and above discussions that, EUV imaging of the global magnetosheath under different SW‐IMF conditions requires an EUV imager with large FOV, high‐sensitivity, large dynamic range, and low intrinsic dark count rate.…”

Section: Discussionmentioning

confidence: 99%

“…4. The EUV emissions produced in the SWCX process in the magnetosheath for disturbed solar wind conditions could achieve or exceed 100 mR, the threshold of current remote sensing EUV imagers [Sandel et al, 2000;He et al, 2013;Chen et al, 2014], near the plasmapause. Therefore, the SWCX EUV emissions in the magnetosheath for highly disturbed SW-IMF conditions should be taken into consideration in processing the Moon-based plasmaspheric EUV images and image inversions.…”

Section: Discussionmentioning

confidence: 99%

EUV emissions from solar wind charge exchange in the Earth's magnetosheath: Three‐dimensional global hybrid simulation

Zhang

Wang

et al. 2015

JGR Space Physics

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In this paper, a three-dimensional (3-D) global hybrid simulation code and a 3-D geocoronal hydrogen model are used to systematically study the extreme ultraviolet (EUV) emissions at 30.4 nm produced by solar wind charge exchange (SWCX) in the Earth's magnetosheath, associated with different solar wind-interplanetary magnetic field (SW-IMF) conditions and different imaging perspectives. We have found that the EUV emission intensities in the magnetosheath are highly variable from several mR to~1200 mR and increase with the flow speed, the density, the temperature, and the He 2+ /H + density ratio of the solar wind; the northward IMF leads to a minimum emission in the magnetosheath, whereas the southward IMF generates a maximum emission; with the increase of the magnitude of IMF, the emission pattern in the nightside splits from single field-aligned shape into a butterfly shape around the magnetic equator; and the EUV emissions vary with the imaging positions, reflecting different latitudinal and longitudinal information of the magnetosheath. It is noted that the SWCX EUV emissions in the magnetosheath for highly disturbed solar wind conditions should be considered in processing the Moon-based plasmaspheric EUV images. We suggest that EUV imaging of the global magnetosheath requires an EUV imager with large field-of-view, high-sensitivity, large dynamic range, and low intrinsic dark count rate. This investigation could provide us with an overall understanding on SWCX EUV emissions in the magnetosheath which can potentially be used to image the global magnetosheath to study the solar wind-magnetosphere coupling in the future.

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“…the image intensity. These high value points show as the bright region in the EUVC image, which is the brightest part of airglow (EUV-BPA) coming from the effects of the plasmaspheric He + 30.4-nm emission (Chen et al 2014;Sandel et al 2003). The Earth, as illustrated in Fig.…”

Section: Feature Analysis Of the Euvc Imagementioning

confidence: 93%

Geocentric position preliminary detection from the extreme ultraviolet images of Chang’E-3

Chen

Ping

Wang

et al. 2015

Astrophys Space Sci

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An Extreme ultraviolet (EUV) Camera was installed onboard the Chinese lunar surface landing mission, the Chang'E-3 lander, as a useful method to observe the Earth plasmasphere. This EUV optical payload obtained more than 600 moon-based Earth plasmasphere images since December 14, 2013. However, due to errors of unknown size and origin in the platform attitude control of the lander and in the EUV telescope pointing control during the mission operating periods, the geocentric coordinates in these EUV images are not fixed in the same position of CCD pixel. Before adequately calibrating, these positioning offsets will introduce extra errors into the analysis of the plasmaspheric structure. With only a little insufficient telemetry information, an effective calibrating method of circle-based differential algorithm is suggested and demonstrated, for automatically and precisely detecting the geocentric position in each EUV image of Chang'E-3 mission. In each EUV image, the tested method uses the outline of a circle as the basic unit to capture the contour for the bright region based on the spectral characteristic. Then, the center of the extracted circle is adopted as the geocentric position for the image. The preliminary analysis shows that this method can effectively detect the geocentric position being always consistent with the recognition result by the basic hand labor method. It is found that the radius of the circles varies from month to month from December, 2013 to May, 2014. The monthly averages of radius show relative notable positive correlation and negative correlation with the changes of both Zenith angle of the Earth at the landing area of Chang'E-3 lander, and B C. Zheng the Earth-moon distance, respectively. This method and results here will benefit the Chang'E-3 EUV study.

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Development and calibration of the Moon-based EUV camera for Chang'e-3

Cited by 22 publications

References 9 publications

A new solar wind‐driven global dynamic plasmapause model: 1. Database and statistics

A new solar wind‐driven global dynamic plasmapause model: 1. Database and statistics

EUV emissions from solar wind charge exchange in the Earth's magnetosheath: Three‐dimensional global hybrid simulation

Geocentric position preliminary detection from the extreme ultraviolet images of Chang’E-3

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