HR: 0800h
AN: SA51B-0235    [Abstracts]
TI: Advanced Automated Solar Filament Detection and Characterization Code: Description, Performance, and Results
AU: * Bernasconi, P N
EM: pietro.bernasconi@jhuapl.edu
AF: Johns Hopkins University / Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 United States
AU: Rust, D M
EM: dave.rust@jhuapl.edu
AF: Johns Hopkins University / Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 United States
AB: We have developed a code for automated detection and classification of solar filaments in full-disk H-alpha images that can contribute to Living With a Star science investigations and space weather forecasting. The program can reliably identify filaments, determine their chirality and other relevant parameters like the filaments area and their average orientation with respect to the equator, and is capable of tracking the day-by-day evolution of filaments while they travel across the visible disk. Detecting the filaments when they appear and tracking their evolution can provide not only early warnings of potentially hazardous conditions but also improve our understanding of solar filaments and their implications for space weather at 1 AU. The code was recently tested by analyzing daily H-alpha images taken at the Big Bear Solar Observatory during a period of four years (from mid 2000 until mid 2004). It identified and established the chirality of more than 5000 filaments without human intervention. We compared the results with the filament list manually compiled by Pevtsov et al. (2003) over the same period of time. The computer list matches the Pevtsov et al. list fairly well. The code results confirm the hemispherical chirality rule: dextral filaments predominate in the north and sinistral ones predominate in the south. The main difference between the two lists is that the code finds significantly more filaments without an identifiable chirality. This may be due to a tendency of human operators to be biased, thereby assigning a chirality in less clear cases, while the code is totally unbiased. We also have found evidence that filaments with definite chirality tend to be larger and last longer than the ones without a clear chirality signature. We will describe the major code characteristics and present and discuss the tests results.
DE: 7509 Corona
DE: 7524 Magnetic fields
DE: 7536 Solar activity cycle (2162)
DE: 7594 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting