How to calculate eclipse for geostationary satellites ?

I have tred to make an online calculator based on a pdf I found at
http://www.cdeagle.com/omnum/shadow1.pdf
The method described in the document can be used to find eclipse for
geostationary satellites
caused by the earth shadow.

I hope I got it right
http://www.satellite-calculations.co...te_eclipse.htm
although I have seen some information indicating that max. eclipse is 72
minutes and not 69m36sec as my
calculator calculates. The reason might be that the suns does not pass
trough the earths atmosphere.

I have used http://www.stjarnhimlen.se/comp/tutorial.html to calculate the
suns declination which I use in
the eclipse ed duration formula, t=
ARCCOS(SQRT(1-R*R)/COS(Sundeclination)*24/pi .


What I now want to do is to calculate when the moon is causing eclipse for
the geostationary satellite.
Does anybody know how to do this ?

I have got the following from some old papers I have:
(it might be from the book Satellite Communication Systems- Design
Principles- M. Richaria)

Solar eclipse caused by the Moon
""""""""""""""""""""""""""""""""""""""""""

The occurence of solar eclipse on a geostationary satellite caused by the
Moon is irregular. It may be recalled that Earth-induced
eclipses are predictable, occurring within +/- 21 days of equinoxes. It is
also necessary to predict the duration and the extent of
occurances of Moon-induced eclipses for spacecraft operations planning. The
technique given here (Siocos,1981) makes use of Sun and Moon
position data available from the Nautical Almanac.

An eclipse occurs when the azimuth/elevation coordinates of the Sun and the
Moon from the satellite position
are equal or close enough to cause the Moon disk to mask the Sun partially
or completely.

The effective elevation, H, of the Sun or Moon from the satellite location
can be obtained from the following equation set:

Cos(Beta)=Cos(d)*Cos(LHA)

Tan(H)= (Cos(beta) - (Ro/Ro+Rs))/Sin(beta)
where d=declination of the stellar object (Sun or Moon)
LHA= local horizon angle
LHA= HAg + Fi
HAg= Hourangle with repect to Greenwich, available from the
Nautical Almanac.

I'm not sure what to use as Ro and Rs. I guess for the sun the declination
of the Sun stellar object is
the same as can be found using the tutorial at
http://www.stjarnhimlen.se/comp/tutorial.html


Does somebody know a good tutorial on how to do such calculations ?

I have been considering using the methods on
http://www.stjarnhimlen.se/comp/tutorial.html and simply use radius of the
earth as
42164km. By using the latitude/longitude of the satellite I should be able
to calculate Suns azimuth/elevation as seen from the satellite.
I think I just need to find a way of calculating Moon azimuth/elevation.


(please dont reply to the e-mail adress as its not working- I dont want to
be spammed..)