28º 17' 53,6" N, +16º 30' 33,44" W
The Optical Ground Station (OGS), installed in the Teide observatory 2400 above the sea level, was built as part of ESA long term efforts for research in the field of inter-satellite optical communications. The original purpose of the station, equipped with a telescope (1m aperture), is to perform the in-orbit test of laser telecommunications terminals on board of satellites in Low Earth Orbit and Geostationary Orbit. Since 2001, the ESA survey of Space Debris in the Geostationary Orbit and the Geostationary Transfer Orbit is also being carried out with a devoted wide field camera attached to the Ritchey-Chretien focus. Furthermore, approximately a third of the observing time is used for basic astronomical research from ESA and IAC science teams with dedicated instruments either in the coudé or in the Ritchey-Chretien foci.
The Optical Ground Station was inaugurated in 1995. The Instituto de Astrofísica de Canarias participated in the integration of the station instruments and has since then been in charge of the station operation. Since January 2001, ESA-ESOC has been carrying out periodic survey campaigns of the space debris in GEO and GTO. This is the contribution of ESA to the worldwide common efforts on this task with NASA and NASDA (National Aerospace and Defense Agency of Japan).
Since November 2001, the bidirectional link with GEO satellite ARTEMIS has been established in more than 100 successful sessions. This is in practice the first world stable free optical laser link ground-satellite. The purpose of this programme is the analysis of the effect of atmospheric turbulence on optical communications performance between ground stations and satellites in the geostationary orbit. Additionally, since 2002, a sodium Laser Guide Star has been implemented by th High Spatial Resolution group in the IAC in order to analyse the short/long term variation of the height, width and density of the sodium mesospheric layer. This study is part of the first generation of adaptative optics instruments development.
In September 2003, it was performed the validation test of the LUCE optical terminal, the optical payload of OICETS satellite succesful launched in august 24th 2005 by NASDA. Finally, since april 2004 a periodical links programe with SMART-1 satellite, in its trip to the moon in order to characterize turbulence effects in the optical links to the deep space, has been carried out.
OGS telescope main features:
- High speed: up to two degrees per second, with highest aceleration 0.5 deg/sec2
- High pointing accuracy: average error in any orientation better than 10arcsec.
- High tracking accuracy: average error 2.5 arcsec/hour
OGS telescope can work using three different configurations, each of them with its own secondary mirror:
- Básic Ritchey-Chrétien, 13,3m focal, small field, useful for some science observations.
- Coudé, 38,95m focal, used for communication tsts with Artemis stellite using an infrared laser.
- Ritchey-Chrétien, 4.5m reduced focal and wide field (0,7x0,7 degrees).
The launching optical system of the communications equipment consists of a 25 W Ion Argon laser to pump a titanium-sapphire laser tunable from 760 to 890 nm (6W). The beam is divided into four sub-apertures in the optical bank in order to mitigate the effect of turbulence in the uplink.
The receiving box of the communications system is equipped with a spectrometer, a polarimeter, an avalanche photodiode feeding a Bit Error Rate analyzer, and a Pointing, Acquisition and Tracking system in closed loop. The LGS is generated with a dye laser tunable in the sodium D2 line (1.5 W).