Contraves Space Ag

Ruag Schweiz Ag

Oerlikon Space Ag

Thales Alenia Space Schweiz Ag

Thomas Dreischer

Johann Kellermeier

Felix Andreas Arnold

Michael Tüchler

Hans Kellermeier

Optical communications system () and method for transmission of payload data (PD) from a low earth orbit satellite () to an optical ground terminal (), the low earth orbit satellite () being connectable with the optical ground terminal () via an optical downlink channel (DL), and the optical ground terminal () being connectable with the low earth orbit satellite () via an uplink channel (UC); wherein said uplink channel (UC) is an acquisition and tracking beacon channel by means of a ground beacon (GB) controlled by a point-acquisition-track subsystem (PAT), the ground beacon (GB) comprising a wide angle beam (W) for acquisition and a guidance beam (G) for tracking; and wherein the ground beacon (GB) for the uplink channel (UC) is a pulse position modulated PPM channel.

Method for optical data transmission from low earth orbit to earth and corresponding communication system

Optical downlink system () and method of optical data transmission between a remote terminal () having a number of n optical communication terminals (OT-OTn), and a ground terminal () comprising a cluster of n optical ground stations (OGS-OGSn) connected by n optical downlink channels (DL-DLn) respectively n optical uplink channels (UC-UCn) characterised by a spatial separation of the optical downlink channels (DL-DLn) and a temporal separation of the optical uplink channels (UC-UCn).

Optical downlink system

Bi-directional laser communications system comprising a first transceiver and a second transceiver for establishing two optical channels there between. The first transceiver comprises a first transmitter with a pulsed high-power laser source for transmitting a pulsed beacon laser signal into a first of said optical channels. The second transceiver comprises a receiver with an optical antenna for receiving said pulsed beacon laser signal, said second transceiver and/or a receiving optic of said second transceiver being adjustable so that it can be adjusted with respect to said pulsed beacon laser signal. The second transceiver further comprises a second transmitter with a laser for transmitting a high energy laser signal into a second of said optical channels, and means for a separation of said first optical channel and said second optical channel. These means prevent the high energy laser signals from being transmitted into said second optical channel whenever said pulsed beacon laser signal is expected to arrive through said first optical channel.

Bi-directional optical communications system and corresponding method

A method and an arrangement for the employment of free space transmission systems for interruption-proof links between individual satellites of satellite communications systems by utilizing optical terminals. The communication link between two satellites is established in a reliable manner despite the presence of microvibrations.

Method and arrangement for an interruption-proof optical satellite linkage

The instant invention relates to a method and an arrangement for the employment of free space transmission systems for interruption-proof links between individual satellites of globally accessible Low Earth Orbiting satellite communications systems by utilizing so-called optical terminals.

Method and arrangement for an interruption-proof optical satellite linkage in LEO networks

In order to achieve a considerable reduction of the outlay required on the ground in connection with the accurate calculation of the exact orbital position of each individual satellite of a constellation, first the exact orbital position of a preferably central master satellite of a sub-group of satellites embodied as a special formation is determined. This calculation is performed autonomously on board the satellite by means of customary measurements supported from the ground, or respectively by means of GPS, MANS, etc. Then the exact position of all other satellites in the same formation is determined from range and pointing data, which are provided by each IS link terminal. These pointing data are well known after the establishment of the inter- satellite link and are continuously updated.

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Opfikon, Switzerland

Thomas Dreischer