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From 1998 to 2003 the CCD Solar Astrolabe of the Observatorio Nacional in Riode Janeiro made more than 20000 observations of the Solar Semidiameter. In thepresent work similar corrections for the observational results of 2002 and 2003were determined. Initially, the values have been corrected in function of theirmean quadratic offset to the local trend averages, therefore without modifyingthe measured variations. Finally, the values have been corrected for the bias,using coefficients obtained from the correlation between some observationalparameters and the observational measures.  Then the total series was compared with series of pointers of the solaractivity. The hypothesis of variation of the semidiameter tied to the solaractivity was examined through the correlations between the different pairs ofpointers. Strong correlations between some pairs were obtained. Next, the samecorrelations were obtained now considering time delays of one series inrelation to the other. Several pairs have shown an increase on the correlation,indicating the presence of a significant phase shift between them. For the pairsolar semidiameter and irradiance the mode of the phase for maximum correlationwas calculated for two distinct cases: either for the complete series of data,or leaving off the data relative to the epochs of the two summits of the solaractivity cycle. The comparison shows that the solar semidiameter respondsclosely to variations of irradiance in the conditions where the peaks ofactivity are considered; inversely, it precedes the variations of irradiance,by at least one hundred days, when the peak values are discarded, thusindicating the existence of two distinct regimes.  We also studied how the semidiameter of the Sun varies throughout itslatitudes. It was noted that each band of latitude has a different response,even so there is a global variation in time.

Diameter and solar figure observations in the solar activity context with the astrolabe of Rio de Janeiro in 1998-2003