Measurements of the solar radius in Antalya between 2001-2003

The results of the solar radius measurements from February 2001 to November 2003 with the solar astrolabe at the TUBITAK National Observatory are presented. The mean semi-diameter for the period, corrected for systematic effects such as the Fried parameter and the zenith distance, is found to be 959.29 +/- 0.01 arc sec. A comparison of the monthly averages of the solar radius with the monthly means of sunspot numbers shows that the semi-diameter of the Sun increases with an amplitude of 0.017 arc sec per year in opposite phase with solar cycle 23.