Hoe spoed koppelvlak vir n nuwe generasie SUNSAT mikrosatelliet

[摘要] ENGLISH ABSTRACT: A micro-satellite is a complex system constructed of a number of subsystems.Communication interfaces must exist between these subsystems to exchange data, forexample telemetric and telecommand. In order to receive all data, these interfaces mustbe efficient and reliable. Failure of an interface can result in an unuseable subsystem,which could affect the satellite.The aim of this thesis was to investigate alternative possibilities for the implementationof a high-speed interface between the main camera and mass-memory. On the firstgeneration SUNSAT the interface was realised by sending the analog image-informationof the different colours, parallel to the mass-memory, where information isconverted to digital data and latched into the main memory. This leads to limitations ofthe interface, and the disadvantages will be discussed. Various parallel and serialtechnologies are investigated and discussed.LVDS was chosen as the most suitable technology and was used to design the interface.This technology has the advantage of implementing a serial bus, using low differentialvoltages for the transmission of data. This minimises the use of power and noise. Thehigh bandwidth of LVDS also allows an errorprotocol to be implemented.As part of the errorprotocol, an EDAC is implemented to correct single biterrors, but itneeds a higher bandwidth, which is a disadvantage. A limited-queue can be used toresend data for any other errors, but it is impractical to implement a bigger memory onthe sending side. The errorprotocol is implemented and simulated and is discussed inthis thesis.

[发布机构] Stellenbosch University