OLSG Report_Final_06_05_12 - Interagency Operations Advisory ...

Optical Link Study Group (OLSG) Final Report
IOAG.T.OLSG.2012.V1
Figure 17: Left: LCT on TerraSAR-X. Right: Image from the test campaign to
test the LEO-to-ground link performance.
With ground stations at Hawaii (Haleakala) and Tenerife (Observatorio del Teide) LEO-toground
and ground-to-LEO links have been established to and from the Tesat LCT on the
NFIRE satellite. For LEO-to-ground links, a 60 mm telescope aperture on the ground is
sufficiently large to collect enough photons to establish the wide band data link. This
aperture is also sufficiently small to ensure that the optical phase across the aperture is not
distorted by the atmosphere (in high altitude atmospheric layers). Table 8 shows the
performance parameters of the ground station for LEO-to-Ground duplex links.
Table 8: Key parameters of the Tesat ground LCT for LEO-to-Ground
communication
Link
Data Rate
Link Distance
Optical Transmit Power
Bit Error Rate
LEO-to-Ground
duplex communication
5.625 Gbps
1.000 km
0.7 W
Error free but burst errors
for the downlink
< 10 -5 for the uplink
Ground Station
Telescope Diameter
60 mm
As for the TerraSAR-X-to-NFIRE inter-satellite link, bit errors are measured for the NFIRE-toground
(Figure 18) and ground-to NFIRE links (Figure 19).
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