Relay platform for communicating telemetry data from one or more moving observation satellite(s) to the ground

Patent metadata

Field	Value
Publication number	US-10707950-B2
Application number	US-201716467959-A
Country	US
Kind code	B2
Filing date	Oct 12, 2017
Priority date	Dec 8, 2016
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

A relay platform for communicating telemetry data from one or more moving observation satellite(s) to the ground is provided. The relay platform for communicating from a space observation system, installed on board an aircraft moving above the clouds, comprises a first reception interface for demodulating telemetry data from at least one moving observation satellite, a second transmission interface for modulating and transmitting the data received to at least one destination ground station. The relay platform comprises a first descending two-level decryption/encryption chain for the telemetry data returned from at least one moving observation satellite(s) to the destination ground station(s).

First claim

The invention claimed is:

1. A communication relay platform of a space observation system, configured to be installed on board an aircraft moving above the clouds, and configured to act as a high-altitude relay for transmitting space observation data, referred to as telemetry data, at a high throughput, between at least one non-geostationary moving observation satellite and at least one target ground station for receiving said data, the transmission from the observation satellite or satellites to the high-altitude relay being capable of taking place during one or more predetermined visibility windows when the moving observation satellite or satellites is visible to the aircraft, and the transmission of data from the aircraft to the ground being capable of taking place constantly,
the relay platform comprising:
a first receiving antenna, configured to receive, in a first optical or radio frequency band, observation data transmitted over a first wireless space downlink linking at least one moving observation satellite to the relay platform, and
a first reception interface, connected to the first receiving antenna and configured to demodulate the data received by the first antenna and save it in a memory, and
a second transmission interface, configured to modulate the observation data stored in the memory, and transmit said modulated data in a second radio frequency band via a second transmission antenna over a second wireless aerial downlink directly linking the relay platform to at least one target ground station, and
the relay platform being wherein it comprises:
a first descending two-level decryption/encryption chain for the telemetry data returned from at least one moving observation satellite to the target ground station or stations.

2. The communication relay platform as claimed in claim 1 , in which
the first frequency band of the first wireless space downlink is an optical or radio frequency band, and/or
the second frequency band of the second aerial downlink is an optical or radio frequency band.

3. The communication relay platform as claimed in claim 1 , further comprising:
a third reception interface configured to demodulate secure telecommand data of the relay platform and/or of the moving observation satellite(s), generated and transmitted over a third dedicated link by a ground control center of the space observation system.

4. The communication relay platform as claimed in claim 1 , in which
the first descending two-level decryption/encryption chain is configured:
for each moving observation satellite and the corresponding received telemetry data, to decrypt, at a first descending level, said telemetry data, encrypted and transmitted by said moving observation satellite over the first space downlink and demodulated by the first interface, by using active keys for decrypting the telemetry data of the first descending level, associated with said moving satellite and with indices of active keys for encrypting/decrypting the telemetry data of the first descending level, said indices of active encryption/decryption keys being transmitted together with said encrypted telemetry data and being associated, in a unique manner, with said moving observation satellite and with said active decryption keys of the first descending level; then
for each target ground station and the corresponding telemetry data intended for same, decrypted at the first descending level and originating from one or more observation satellites, to encrypt, at a second descending level, the telemetry data decrypted at the first descending level by using an active key for encrypting the telemetry data of the second descending level, associated with said target ground station, and to append, to said encrypted data of the second descending level, an index of an active key for encrypting/decrypting the telemetry data of the second descending level, associated, in a unique manner, with said target ground station and with said active encryption key of the second descending level.

5. The communication relay platform as claimed in claim 4 , in which
the first descending two-level decryption/encryption chain for the telemetry data, returned from the moving satellite(s) to the target ground station(s), comprises a first module for managing the descending two-level encryption/decryption keys, a second module for decrypting, at a first descending level, the telemetry data transmitted over the first space downlink and demodulated by the first interface, and a third module for encrypting, at a second descending level, the telemetry data decrypted at the first descending level; and
the first module for managing the descending two-level encryption/decryption keys for the telemetry data is configured to;
initially receive a first group of one or more sets of keys for decrypting telemetry data of the first descending level; and
initially receive a second group of one or more sets of keys for encrypting telemetry data of the second descending level; and
each set of keys for decrypting telemetry data concerning the first descending level is associated with a moving observation satellite, and each key for decrypting telemetry data at the first descending level of each set is paired with and identified in a unique manner by an index of an encryption/decryption key of the first descending level; and

each set of keys for encrypting telemetry data concerning the second descending level is associated with a target ground station, and each key for encrypting telemetry data at the second descending level of each set is paired with and identified in a unique manner by an index of an encryption/decryption key at the second descending level.

6. The communication relay platform as claimed in claim 5 , in which
the first module for managing the descending two-level encryption/decryption keys for the telemetry data is configured to execute, on receipt, via the third interface, of dedicated telecommands secured and sent by the ground control center, modifications of part or all of the keys for decrypting the telemetry data at the first descending level and/or the keys for encrypting telemetry data at the second descending level.

7. The communication relay platform as claimed in claim 4 , in which
the first receiving antenna, the first reception interface and the memory are configured to separately receive, demodulate and save telemetry data, encrypted at the first descending level and transmitted by at least two non-geostationary moving observation satellites over the first space downlink, and/or
the second transmission antenna and the second transmission interface are configured to separately modulate and transmit the telemetry data encrypted at the second descending level to at least one target ground station over the second wireless aerial downlink; and
the first descending two-level decryption/encryption chain for the telemetry data, returned from the moving satellite(s) to the target ground station(s), comprises a matrix allocator for allocating the decrypted telemetry data, received from a given moving observation satellite, to different target ground stations, according to an allocation table loaded with telecommands,
the matrix allocator being connected in series between the second decryption module and the third encryption module.

8. The communication relay platform as claimed in claim 1 , further comprising:
a second ascending two-level decryption/encryption chain for the telecommand data of the moving observation satellite(s) received via the third reception interface of the third dedicated link for secure telecommands originating from the ground control center.

9. The communication relay platform as claimed in claim 8 , in which
the second ascending two-leve

Assignees

• Thales Sa

Inventors

• Martinerie Francis
• Sainct Hervé
• Taride Serge
• Gayrard Jean Didier

Classifications

• B64U2101/20

  for use as communications relays, e.g. high-altitude platforms · CPC title

• H04W12/03

  Protecting confidentiality, e.g. by encryption · CPC title

• H04W4/40

  for vehicles, e.g. vehicle-to-pedestrians [V2P] · CPC title

• G06T2207/30181

  Earth observation · CPC title

• H04B7/18504 Primary

  Aircraft used as relay or high altitude atmospheric platform · CPC title