Center of Box Definition
Geosynchronous satellites are assigned specific longitudinal positions above the equator. To reduce adjacent satellite interference, satellite stations or "boxes" are defined at these positions in the east-west and north-south directions.
A satellites box size is assigned based upon its operational frequency band and is defined as follows:
Satcom C1: Assigned longitude +0.10° and 0° latitude +0.10° (box size of 0.20° in the E-W/N-S directions); approximately 90 miles on a side. All other Spacecraft: Assigned longitude +0.05° and 0° latitude + 0.05° (box size of 0.10° in the E-W/N-S directions); approximately 45 miles on a side.
Satellite Box Center is a smaller box defined as the assigned longitude ±0.005° and 0° Latitude ±0.005°. This is essentially a smaller box approximately 4.5 miles on a side. It is normal for satellites to move within their box due to gravitational and other effects associated with the Earth, sun, and moon. It is important that ground station antennas are aligned when the satellite is passing through box center for peak performance. Return to Center of Box