Automated detecting and removing cloud shadows in full-disk solar images

被引：7

作者：

Feng, Song ^{[1
,2
,3
]}

Lin, Jiaben ^{[2
]}

Yang, Yunfei ^{[1
,2
]}

Zhu, Haibo ^{[1
]}

Wang, Feng ^{[1
]}

Ji, Kaifan ^{[1
]}

机构：

[1] Kunming Univ Sci & Technol, Fac Informat Engn & Automat, Yunnan Key Lab Comp Technol Applicat, Kunming 650500, Peoples R China

[2] Chinese Acad Sci, Natl Astron Observ, Key Lab Solar Act, Beijing 100012, Peoples R China

[3] Nanjing Univ, Minist Educ, Key Lab Modern Astron & Astrophys, Nanjing 210093, Jiangsu, Peoples R China

来源：

NEW ASTRONOMY | 2014年 / 32卷

基金：

中国国家自然科学基金;

关键词：

Methods: data analysis; Techniques: image processing; Sun: general; NETWORK; RECOGNITION;

D O I：

10.1016/j.newast.2014.03.006

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Sky clouds affect full-disk solar observations significantly. Their shadows obscure the details of solar features in observed images. Cloud-covered images are difficult to be used for further research without pre-processing. We proposed a technique for detecting and removing cloud shadows in full-disk solar images. In the detection procedure, a two-step approach is applied: (1) identifying the deviation of a cloud-covered image from a perfect disk; (2) quantifying the cloud cover by an index that we defined in this paper. In the removal procedure, the transmittance of clouds is measured by comparing the cloud-covered image with a "Quiet Sun" that getting from a normal observation. A restored cloud-free image can be obtained after correcting the absorption by clouds. We tested the procedures using the full-disk solar Ha images of the Global Oscillation Network Group (GONG), and utilized the structural similarity (SSIM) algorithm for evaluating the performance of image restoration. The results demonstrate that both procedures are significant effective, and that the cloud-covered image is restored not only in visual effect but also in intensities of solar features. (C) 2014 Elsevier B.V. All rights reserved.

引用

页码：24 / 30

页数：7

共 17 条

[1]

[Anonymous], ADV CHALLENGES MULTI

[2]

[Anonymous], P AISB

[3] Synoptic Hα full-disk observations of the sun from big bear solar observatory -: I.: Instrumentation, image processing, data products, and first results [J].

Denker, C ;

Johannesson, A ;

Marquette, W ;

Goode, PR ;

Wang, H ;

Zirin, H .

SOLAR PHYSICS, 1999, 184 (01) :87-102

[4] Filament recognition and image cleaning on Meudon Hα spectroheliograms [J].

Fuller, N ;

Aboudarham, J ;

Bentley, RD .

SOLAR PHYSICS, 2005, 227 (01) :61-73

[5]

Fuller N, 2004, LECT NOTES ARTIF INT, V3215, P467

[6] Active-region monitoring and flare forecasting - I. Data processing and first results [J].

Gallagher, PT ;

Moon, YJ ;

Wang, HM .

SOLAR PHYSICS, 2002, 209 (01) :171-183

[7]

Harvey J.W., 2011, AAS/Solar Physics Division Abstracts, P1745

[8] The Global Oscillation Network Group (GONG) project [J].

Harvey, JW ;

Hill, F ;

Hubbard, RP ;

Kennedy, JR ;

Leibacher, JW ;

Pintar, JA ;

Gilman, PA ;

Noyes, RW ;

Title, AM ;

Toomre, J ;

Ulrich, RK ;

Bhatnagar, A ;

Kennewell, JA ;

Marquette, W ;

Patron, J ;

Saa, O ;

Yasukawa, E .

SCIENCE, 1996, 272 (5266) :1284-1286

[9] THE GLOBAL OSCILLATION NETWORK GROUP SITE SURVEY .2. RESULTS [J].

HILL, F ;

FISCHER, G ;

FORGACH, S ;

GRIER, J ;

LEIBACHER, JW ;

JONES, HP ;

JONES, PB ;

KUPKE, R ;

STEBBISN, RT ;

CLAY, DW ;

INGRAM, RL ;

LIBBRECHT, KG ;

ZIRIN, H ;

ULRICH, RK ;

WEBSTER, L ;

HIEDA, LS ;

LABONTE, BJ ;

LU, WMT ;

SOUSA, EM ;

GARCIA, GJ ;

YASUKAWA, EA ;

KENNEWELL, JA ;

COLE, DG ;

ZHEN, H ;

SUMIN, X ;

BHATNAGAR, A ;

AMBASTHA, A ;

ALKHASHLAN, AS ;

ABDULSAMAD, MS ;

BENKHALDOUN, Z ;

KADIRI, S ;

SANCHEZ, F ;

PALLE, PL ;

DUHALDE, O ;

SOLIS, H ;

SAA, O ;

GONZALEZ, R .

SOLAR PHYSICS, 1994, 152 (02) :351-379

[10]

Loza A., 2006, 2006 9 INT C INFORM, P1

← 1 2 →