Automatic extraction method for sun outline

Abstract

The invention belongs to the solar physics of the field of astronomy in China and provides an automatic extraction method for the sun outline. The method comprises the following steps: aiming at the full-disk monochromatic image of the Huairou Solar Observing Station of the National Astronomical Observatories of China, obtaining the gray scale information of the solar limb by using morphological close operation and erosion operation; then, extracting a limb coordinate by using a self-adaptive threshold method; finally, fitting the limb coordinate by combining a least square fitting method, and thus obtaining a connected solar limb binary image. Compared with other international algorithms, the method can process lower-quality solar observation data with instrument noise and fills the blank of domestic related fields. The method has important significance and practical value on determining the solar disk radius and the earth-sun distance, calculating the position of solar activity in the solar disk and researching the evolution law of the sun outline.

Description

technical field [0001] The invention belongs to the image processing technology in the field of solar physics, in particular to a method suitable for automatic extraction of solar contours. Background technique [0002] The sun is a typical star, which is inseparable from human life and production activities. The sun's light and heat warm the earth and maintain the proper environment necessary for human survival and all life activities on the earth. The changes of the four seasons, the alternation of day and night, the wind, cloud, rain and snow, and the growth of plants that we see are all the result of the action of the sun (references [1-3]). However, intense solar activity will also disturb the solar-terrestrial space and the upper atmosphere of the earth, causing a series of important phenomena, and affecting the safety of space flight, life estimation of artificial satellites, radio communication, polar power system, geophysical prospecting, Meteorological and hydrolo...

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Problems solved by technology

[0005] The automatic extraction method of the sun profile has been proposed in the world (reference [9]), however, this method mainly uses the data obtained by the space telescope for processing, because the resolution of this data is relatively high due to the fact that it is not interfered by the earth's atmosphere , in comparison, the full-helix monochrome image of HSOS in my country is collected through ground-based observation and has limited resolution, and the current methods cannot be well applied; while in China, research in this area has not yet been carried out, and it is still a blank area

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