Umesh S.B.,Computers and Star Sensor Group |
Prasad B.K.,Computers and Star Sensor Group |
Vijaya Y.,Computers and Star Sensor Group |
Shashikala T.H.,Computers and Star Sensor Group |
Rao G.N.,Computers and Star Sensor Group
Journal of Spacecraft Technology | Year: 2011
An embedded core for high-speed SpaceWire data communication link, based on European Space Agency standard ECSS-E-50-12A, is designed and developed in hardware description language VHDL. The core is tested and validated for its application in multi-head star tracker system. Such star tracker has a single centralized attitude processing unit interfaced to multiple camera head units through SpaceWire data links. Commanded by attitude processing unit, the camera head units that have either a Charge Coupled Device or an Active Pixel Sensor as its imaging device, captures the full frame in acquisition mode or predicted window image of stars in track mode and transfers the image data to attitude processing unit via the high speed SpaceWire link. The attitude processing unit then performs the computation of star centroids, star identification with on-board catalogue, attitude quaternion computation and transmission of attitude data to spacecraft attitude and orbit control system via MIL-STD-1553B interface. The SpaceWire link is interfaced to a 32-bit embedded processor LEON3 using Advanced Microbus Architecture and the full core is implemented in 1330 micro-cells on a single chip Xilinx XQVR600 FPGA. The developed SpW link is tested and validated up to 12 Megabits/s using STAR-Dundee SpaceWire protocol validation tool.