Grundig Digital Radio User Manual

DIGITAL RADIO GUIDE

SATELLITE TRANSMISSION - SIRIUS / XM

74

Dry Mass

1300 kg

1575 kg

RF power (operating)

2.5 kW

4 kW

DC power – EOL
Solar Array
Battery

7.5 kW
7.5 kW

8.5 kW
8.8 kW

Control System

3-wheel mom bias

4-wheel mom bias
On-board orbit 
propagator

Control Modes

Orbit Normal

Orbit Normal
Yaw Steering

TX Antenna

Fixed Gregorian
Gain 27.8 dBi;
Cross-pol 24 dB

Gregorian; two axis 
steering 360º rotating 
shaped subreflector
Gain 27.2 dBi; Cross-
pol 28 dB

RX Antenna

Fixed offset fed

Offset fed; two axis 
steering

Solar array

2x4 panel HES

2x5 panel HES

Battery

2x32 cell - 149 AH

2x34 cell - 178 AH

TT&C

X, C and S bands
CONUS ground station
Limited motion antennas

C and S bands
2 near equatorial 
ground stations  Full 
motion antennas

Launch Vehicle

Ariane

Proton

The launch of the Sirius Satellite Radio constellation marks the first use of satellites for
Digital Audio Radio Service broadcasting in the United States. The three high power
direct broadcast satellites will provide service for millions of subscribers. The Sirius Radio 
system is the world’s first satellite broadcast system using non-geostationary orbits. 

The use of inclined elliptical orbits coupled with multiple modes of transmission diversity
provides notable advantages for broadcast service to the mobile market. Pioneering
technology was developed and implemented by Sirius Satellite Radio and Space
Systems/Loral in order to accomplish this unique achievement.

Current population and transmission status of Sirius and XM satellite radio services is
shown in the following chart.

100%

3 in HEO

~100

100%

2 in GSO

~800