All the observations were reduced using the DE200/LE200 ephemeris of the Sun. The orientation of the local reference frame is obtained by means of the Earth rotation parameters (polar coordinates and UT1-UTC) interpolated from Bulletins B published by the Central Bureau of the International Earth Rotation Service (IERS). A detailed description of the reduction method applied at Santiago for solar observations was given by Chollet & Noël (1993).
The average annual values of the differences in right ascension
(astrolabe-ephemeris) and those of the observed Sun semidiameter reduced to the
astronomical unit, obtained during the period 1995-1997 and during former
years of the solar program are given in Table 1.
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The individuals results of the observations at and
for
the period 1995-1997 are reported in Tables 2 and 3 respectively (accesible
only in electronic form) with results of former observational periods. The
following information is available from these tables:
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