  This work deals with the comparison of different parameters (French/IMCCE and
US/JPL ephemerides) used to calculate the extension of the umbral shadow and
the location of the centre line in the total solar eclipse that took place on
March, 29th 2006. We needed to know the exact points where the predicted
duration of the solar eclipse was 0 seconds. This phenomenon allows, observed
on this particular position, the measurement of the solar diameter. The work is
composed by three parts. In the first one is described the evolution of the
lunar theory from Hipparchus to the current theory (Bureau de Longitudes/IMCCE,
Chapront). The second part is dedicated to geodesy (WGS84 datum) and there are
examples of longitude's calculations. In the third one there is the analysis of
the parameters to understand the reasons about the different extensions of the
umbral shadow and the different positions of the centre line in the solar
eclipse calculated respectively with French and American ephemerides. The use
of the center of the figure of the Moon with respect to the center of mass
produces the differences in the ephemerides. This work prepared the
observational mission in Egypt to observe the total solar eclipse from the
shadow's edges in Zawayet al Mahtallah, near Sidi Barrani, whose results were
after published in Solar Physics vol. 259 p. 189 (2009).
