SLM-5650 Satellite Modem Revision 2

Configuration MN/SLM5650.IOM

3–16

S
A
T
E
L
L
I
T
E
M
O
T
I
O
N
A
N
D
O
R
B
I
T
A
L
I
N
C
L
I
N
A
T
I
O
N
SATELLITE
NOMINAL
POSITION
N
S
GEO-SYNCHRONOUS
EQUATORIALORBIT
GEO-SYNCHRONOUS
INCLINEDORBIT
SATELLITE
N/S
MOTION
N
S
A
B
C
A
ASSTATION-KEEPING FUEL
BECOMESEXHAUSTED, THE N/S
STATION-KEEPINGIS LIMITED
TOPRODUCE A MORE I NCLINED
ORBIT,THUS PROLONGING THE
LIFEOF THE SATELLITE.
ASATELLITEIS MAINTAINEDAT AN
ASSIGNEDGEOSTATIONARY
LOCATIONTHROUGH THE US E OF
GROUNDCOMMAND ADJ USTMENTS
TOITS N/S AND E/WLOCATION. THIS
PROCESS,KNOWN AS SATELLITE
STATION-KEEPING,IS USEDTO KEEP
THESATELLITE DRIFT WITHIN
CERTAINBOUNDARIES.
THEN/S MOTION CHANGES THE
PATHFROM THE SATELLITE TO THE
EARTH,RESULTING IN FREQUENCY
CHANGESKNOWN AS THE DOPPLER
EFFECT.
Figure 3-4. Doppler Shift