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ASSA (Automatic Solar Synoptic Analyzer)Sunhak Hong1,2, Sangwoo Lee3, Seung Jun Oh3, Jae Hun Kim1, Gi-Chang Yoon1, Jae-Hyung Lee1,2, Young-Kyu Kim1, Jaehyung Lee1, Yong Jae Moon2 and Dong-Hun Lee2
1: Korean Space Weather Center, RRA, Jeju, Korea., 2: School of Space Research, KHU, Young-in, Korea., 3: SELab, Inc., Seoul, Korea
AbstractWe have developed an automated software system of identifying solar active regions, filament channels, and coronal holes, those are three major solar sources causing the space weather. Space weather forecasters of NOAA Space Weather Prediction Center produce the solar synoptic drawings as a daily basis to predict solar activities, i.e., solar flares, filament eruptions, high speed solar wind streams, and co-rotating interaction regions as well as their possible effects to the Earth. As an attempt to emulate this process with a fully automated and consistent way, we developed a software application named ASSA(Automatic Solar Synoptic Analyzer). When identifying solar active regions, ASSA uses high-resolution SDO HMI intensitygram and magnetogram as inputs and providing McIntosh classification and Mt. Wilson magnetic classification of each active region by applying appropriate image processing techniques such as thresholding, morphology extraction, and region growing. At the same time, it also extracts morphological and physical properties of active regions in a quantitative way for the short-term prediction of flares and CMEs. When identifying filament channels and coronal holes, images of global H-alpha network and SDO AIA 193 are used for morphological identification and also SDO HMI magnetograms for quantitative verification. The output results of ASSA are routinely checked and compared with NOAA's daily SRS (Solar Region Summary) and UCOHO (URSIgram code for coronal hole information).
The key parameters for the classification and detection The Text Output from ASSAThe Process Flow in ASSA
Data I/O
Preprocess
Characterize
Detect & Classify
Compare&Verify
Archive
Masking, Flattening, Exposure correction, limb darkening
correction… etc
SDO HMI & AIA, Ground H-alpha, etc.
(JPEG, JP2)
Existence of penumbra, polarity, neutral line, compactness, asymmetry, ellipticity, etc
Quantified thresholds for detection and classification
McIntosh and Mag class, Location, Area, Number of spots, the derived physical parameters,
etc.
Parameter Value Unit
factor of standard deviation to be subtracted from mean intensity to determine threshold intensity for sunspot detection
6.0 None
factor of standard deviation to be applied to standard-deviation-based region growing
1.5 None
maximum separation between two sunspots to be considered to belong to the same spot group
6.0 Degree
maximum separation between sunspots to determine unipolar or bipolar
3.0 Degree
factor of group width to determine threshold of distance between spots with penumbra
0.5 None
ratio (penumbral area / entire spot area) to determine threshold of maturity of penumbra
0.2 None
threshold of asymmetry of outline ellipse of spot 25 if spot area > 10050 if spot area < 100 None
threshold of north-south diameter of spot 2.5 Degree
threshold of ratio (sum of spot areas / entire group area) to determine compactness
0.4 None
threshold of ratio (plus polarity / minus polarity) to determine alpha or beta
0.2, 5.0 None
threshold of number of effective neutral lines separating opposite polarity to determine beta or beta-gamma
2 None
Parameter Value Unit
factor of median intensity of solar disk to determine candidates for coronal hole
0.45 None
threshold of skewness of polarity distribution inside coronal hole area
skewness of polarity distribution over entire
solar diskNone
factor of median intensity of solar disk to determine candidates for filament
0.82 None
factor of median intensity of solar disk to determine candidates for sunspot
0.65 None
factor of standard deviation to be applied to standard-deviation-based region growing
2.0 None
structuring elements for detection of filament-like elongated feature
None
maximum separation between two fragments to be considered to belong to the same filament
40 Pixel
NOAA SRS reportUCOHO
Item Description Unit
ASSA Number Four-digit number of each sunspot group None
Num Spots Number of sunspots None
Num Spots (with penumbra) Number of sunspots with penumbra None
Location Heliographic Coordinate Degree
Area Area of group region one millionth of solar disk area
McIntosh Class Result of McIntosh classification None
Mag Class Result of Wilson magnetic classification None
Total Number of Spots Total number of sunspots for entire solar disk None
Wolf Number 10G+S (G: number of groups, S: number of spots) None
The key parameter and its corresponding threshold value for the sunspot classification for Macintosh class and the Wilson magetic Class (Table 1.) and the detection of Corona Home and filmament channels (Table 2.)
Table 1. Table 2.
Figure 1. The conceptual diagram for the process flow from the data ingestion to final archive in ASSA. The examples of the data types, pre-processing, physical parameters and the comparison data is shown on the right in the box.
Figure 2. The text output retrieved from ASSA for active region classification. The output is created with 1 hour cadence, and archived in the database in Korea Space Weather Center, RRA.
The Results from the test-run of ASSA
Figure 3. The results from the test-run of ASSA. The captured image of ASSA Graphic User Interface for interactive running by tuning the threshold and the appropriate input parameters (a), The classification results from ASSA(red) compared with the SRS (green) by SWPC, NOAA. (b), the magnetic classification results from ASSA (red) compared with the SRS (green) by SWPC, NOAA.(c), the corona hole detection results from ASSA (orange line) compared with the UCOHO results (blue line,(d)), and the filament channel detection results from ASSA (e)
SH 13A-2239, AGU Fall Meeting, 2012Acknowledgement to colleagues of NOAA Space Weather Center for sharing their knowledge and experiences on space weather. Special thanks to Mr. Ken Tegnell for his great mentoing to the new space weather forecasters of Korea.
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