Study Of Telescience Video And Image Communication Based On Ccsds Protocol For Advanced Orbiting Systems

To develop space science experiment systems on the unmanned space platforms , telescience is one of the most popular methods. For the purpose of data handling and data communication in the space missions, the standard of CCSDS (Consultative Committee for Space Data Systems) Advanced Orbiting Systems is introduced into many countries. According to the technical report of "Demonstration Report of Space Station's AOS Scheme"how to monitor space science experiment is discussed in this paper.In addition,a model of tele-operation is proposed ,whieh can demonstrate how tele-operation working and verify technical elements of telescience. Many AOS services are discussed and verified, including "Internet service", "Path service", "Encapsulation service","Multiplexing service", "Bitstream service","Virtual Channel Access service",and "Virtual Channel Data Unit service". Each service is expected to be used for special purpose with its own service data unit. The Path service is expected to be used primarily for transferring, at moderate to very-high data rates, large volumes of structured, delimited data units between fairly static source and destination associations. The Bitstream service breaks the stream of bits from each SLS (Space Link Subnetwork) user into blocks which are sized to exactly load the fixed-length data field of one dedicated Virtual Channel Data Unit. The Multiplexing service provides a facility whereby variable?length, delimited,octet-aligned service data units, which conform to the Version-1 CCSDS Packet format. The Virtual Channel Data Unit service provides a facility whereby a fixed-length, octet-aligned VCDU or CVCDU, created by an independent SLS entity, may be transferred across the SLS. To transfer telescience video and image data, many formats can be used. In the paper JPEG(Joint Picture Expert Group) and MPEG-1 (Moving Pictures Expert Groups) are discussed. And a software is developed to capture a image, to compress bitmap image data to JPEG image data, and to decompress to JPEG image to bitmap image data. Also how to capture video streams and playback video streams are discussed. The demonstration system consists of computers, testing network, testing software and video capture devices which can demonstrate how the space data be sent to and received from space/ground platform.