Derivation of the Correction Coefficient k in the Relative Sunspot Number for a New Sunspot Observing System at Mitaka.

Accession number;99A0938789
Title;Derivation of the Correction Coefficient k in the Relative Sunspot Number for a New Sunspot Observing System at Mitaka.
Author; MIYASHITA MASAKUNI (Natl. Astron. Obs.) SUEMATSU YOSHINORI (Natl. Astron. Obs.) IRIE MAKOTO (Natl. Astron. Obs.)
Journal Title;Report of the National Astronomical Observatory of Japan
Journal Code:F0086B
ISSN:0915-6321
VOL.4;NO.3;PAGE.149-155(1999)
Figure&Table&Reference;
Pub. Country;Japan
Language;Japanese
Abstract;A new sunspot observing system using a CCD of 2 k*2 k pixels has started at Mitaka, since April 1998. To determine the personal correction coefficient k in the formula for the relative sunspot number. we compared the sunspot numbers from the new system with those from conventional hand-drawing observations at our observatory and from S.I.D.C. (Sunspot Index Data Center). As a result, we obtained k=1.0 on the average for the new system. There were, however, some cases in which the k-value largely deviates from the average. The new system cannot always detect a small sunspot group because of its poor spatial resolution, or it detects sometimes a pseudo-sunspot due to its incomplete gain-correction in bad seeing or poor focusing conditions, although most pseudo-sunspots can be easily perceived because they do not rotate with time. These problems will not be serious, especially when the solar activity is high and the number of sunspots is large, although they should be borne in mind by data handlers. We will be hereafter reporting the relative sunspot number of Mitaka using k=1.0. (author abst.)
Related Articles;
Loading...