Precise Orbit Determination of Global Navigation Satellite System of ...
Precise Orbit Determination of Global Navigation Satellite System of ...
Precise Orbit Determination of Global Navigation Satellite System of ...
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Chapter 8 Geostationary <strong>Orbit</strong> <strong>Determination</strong> And Prediction During <strong>Satellite</strong> Maneuvers<br />
= G M (<br />
m m<br />
It is known that<br />
1<br />
xmx+ ymy+ zmz −<br />
/ )<br />
( x − x) + ( y − y) + ( z −z)<br />
( xm + ym + zm)<br />
2 2 2 2 2 2 3 2 (8-32)<br />
m m m<br />
2 2 2 2 2 2<br />
i i i i i i i i<br />
| r − r| = ( x − x) + ( y − y) + ( z − z) = r − 2(<br />
x x+ y y+ z z) + r<br />
and r r<br />
i >> , then<br />
1 1 �<br />
2<br />
2(<br />
xx i + yy i + zz i ) r �<br />
= �1<br />
−<br />
2 + 2 �<br />
| ri − r| ri<br />
� ri<br />
ri<br />
�<br />
and<br />
ri⋅ r xx i + yy i + zz i<br />
cosδ = =<br />
rr rr<br />
thus<br />
i<br />
1 1 � ��<br />
−2ri⋅r r 2 ��<br />
�<br />
= �1<br />
+ �(<br />
) + ( )<br />
2 ��<br />
| ri − r| ri<br />
��<br />
�� ri<br />
ri<br />
�� ��<br />
i<br />
1<br />
−<br />
2<br />
1<br />
−<br />
2<br />
⋅ ��<br />
⋅<br />
��<br />
= + + � − �<br />
��<br />
�� +<br />
1 � r �<br />
i r 3 rir 2 1 r 2<br />
�1<br />
( ) ( ) Λ<br />
2 2<br />
�<br />
ri<br />
��<br />
ri<br />
2 ri<br />
2 ri<br />
��<br />
�<br />
2<br />
3<br />
1 r r 1 3 2 r 3 5 2 �<br />
= �1<br />
+ cos δ + 2 ( − + cos δ) + 3 ( − cosδ + cos δ) + Λ �<br />
ri<br />
� ri<br />
ri<br />
2 2 ri<br />
2 2 �<br />
R GM i i � 2<br />
3<br />
r 1 3 2 r 3 5 3 �<br />
i = �1<br />
+ 2 ( − + cos δ) + 3 ( − cosδ + cos δ) + Λ �<br />
(8-33)<br />
ri<br />
� ri<br />
2 2 ri<br />
2 2 �<br />
Removing the constant term in Eq.(8-33), Eq.(8-33) becomes<br />
R<br />
i<br />
GM i i � 2<br />
3<br />
r 1 3 2 r 3 5 3 �<br />
= � ( − + cos δ) + ( − cosδ + cos δ) + Λ<br />
2<br />
3<br />
�<br />
(8-34)<br />
ri<br />
��<br />
ri<br />
2 2 ri<br />
2 2 ��<br />
In the equations above subscript i means s or m, i.e. the Sun and the Moon respectively. The relations between δ<br />
and satellite orbit parameters are shown in the following figure.<br />
γ<br />
O<br />
ε<br />
δ<br />
S/M<br />
N<br />
i<br />
100<br />
N´<br />
<strong>Orbit</strong> Plane<br />
i -<br />
Sat.<br />
Figure 8-1 Relations between <strong>Satellite</strong> and Sun/Moon<br />
ε<br />
Sun /Moon <strong>Orbit</strong> Plane<br />
Equator<br />
In Figure 8-1 ε is the obliquity <strong>of</strong> the ecliptic. The arc between γ and N ′ is defined as Ω. The arc between<br />
satellite and N ′ as v + ω . The arc between γ and Sun/Moon as v′ + ω ′ ,