Search results
Results from the WOW.Com Content Network
The Consultative Committee for Space Data Systems packet telemetry standard defines the protocol used for the transmission of spacecraft instrument data over the deep-space channel. Under this standard, an image or other data sent from a spacecraft instrument is transmitted using one or more packets.
A packet is a block of data with length that can vary between successive packets, ranging from 7 to 65,542 bytes, including the packet header. Packetized data is transmitted via frames, which are fixed-length data blocks. The size of a frame, including frame header and control information, can range up to 2048 bytes.
How satellite internet works. Satellite Internet generally relies on three primary components: a satellite – historically in geostationary orbit (or GEO) but now increasingly in Low Earth orbit (LEO) or Medium Earth orbit MEO) [20] – a number of ground stations known as gateways that relay Internet data to and from the satellite via radio waves (), and further ground stations to serve each ...
Free-space optical communication (FSO) is an optical communication technology that uses light propagating in free space to wirelessly transmit data for telecommunications or computer networking. "Free space" means air, outer space, vacuum, or something similar. This contrasts with using solids such as optical fiber cable.
In outer space, the communication range of free-space optical communication is currently of the order of hundreds of thousands of kilometers. [1] Laser-based optical communication has been demonstrated between the Earth and Moon and it has the potential to bridge interplanetary distances of millions of kilometers, using optical telescopes as ...
SpaceWire also proposes the use of space-qualified 9-pin connectors. SpaceWire and IEEE 1355 DS-DE allows for a wider set of speeds for data transmission, and some new features for automatic failover. The fail-over features let data find alternate routes, so a spacecraft can have multiple data buses, and be made fault-tolerant. SpaceWire also ...
With passive satellites, the reflected signal is not amplified at the satellite, and only a small amount of the transmitted energy actually reaches the receiver. Since the satellite is so far above Earth, the radio signal is attenuated due to free-space path loss , so the signal received on Earth is very weak.
In CNAV, at least 1 out of every 4 packets are ephemeris data and the same lower bound applies for clock data packets. [25] The design allows for a wide variety of packet types to be transmitted. With a 32-satellite constellation, and the current requirements of what needs to be sent, less than 75% of the bandwidth is used.