Title :
Optimization of parameters of mapping of the solar disk in 3 mm range
Author :
Antonov, A.V. ; Gerasimov, Yu.M.
Author_Institution :
Inst. of Radio Astron., Nat. Acad. of Sci. of Ukraine, Kharkiv, Ukraine
Abstract :
On radio telescope RT-2 mapping of the Sun is carried out by scanning of its image in right ascension α at various angles of declination δ. For a required angular resolution at. image reconstruction about 1´ the registered image of the Sun in a square window in size 1°×1° should represent a matrix in size 64×64 an element. In the specified window time of obtaining of one scan makes value about minutes. Therefore time of obtaining of the full matrix size 64×64 an element exceeds 6 hours. This time is unacceptable for registration of nonstationary processes. In most cases sizes of active formations (AF) are comparable with achievable resolution that does not allow to restore their spatial structure. Nevertheless, restoring of AF allows to define such relevant arguments, as their angle sizes, coordinates and brightness temperature. These parameters can be received not only at detail mapping the Sun, but also on the basis of recovery single one-dimensional orthogonal scans areas of arrangement of AF. Presence of orthogonal scans of area from AF allows to execute a bearing of AF and to determine their spatial sizes and coordinates. Each of restored orthogonal cross-sections gives appropriate sizes of AF, their centers of gravity and integral brightness temperature. Orthogonal coordinates of the centers of gravity determine position of AF on the solar disk. The restored orthogonal sizes determine the greatest possible sizes of AF. The exactitude of a bearing and restoring of brightness temperature of AF depends on ratio of its angle sizes and width of directivity. diagram. of radio telescope, and also from angular distance between orthogonal sections and the real standing of AF.
Keywords :
brightness; image reconstruction; image registration; radioastronomical techniques; radiotelescopes; solar activity; solar eclipses; active formations; angular resolution; brightness temperature; image reconstruction; mapping parameters optimization; normalizing factor; one-dimensional orthogonal scanning; orthogonal cross-sections; radiotelescope directional diagram model; solar disk mapping; spatial structure; square matrix; Brightness temperature; Equations; Gravity; Image reconstruction; Image resolution; Image restoration; Radio astronomy; Spatial resolution; Sun; Temperature distribution;
Conference_Titel :
Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves, 2004. MSMW 04. The Fifth International Kharkov Symposium on
Print_ISBN :
0-7803-8411-3
DOI :
10.1109/MSMW.2004.1346233