Com network speeds space sensor test data

Experts at the U.S. Air Force Arnold Engineering Development Center in Tullahoma, Tenn., are responsible for testing the space-based infrared and visible sensors in threat detection and tracking, and target discrimination, but data that needed to be processed in real time was overwhelming their distributed test system.

Experts at the U.S. Air Force Arnold Engineering Development Center in Tullahoma, Tenn., are responsible for testing the space-based infrared and visible sensors in threat detection and tracking, and target discrimination, but data that needed to be processed in real time was overwhelming their distributed test system.

The system, known as the Focal Plane Array Test Chamber (FPATC), had to transfer huge amounts of video frame data among its nine subsystems during a test shift at speeds sufficient to meet the real-time requirements of mission simulations. The FPATC network is an 11-node system that comprises a Q-bus Digital VAX system, EISA-bus PCs, and Arnold-designed digital signal processor boards. Input files range up to 5.4 Gbytes/second and output files as large as 2.7 Gbytes.

To achieve real-time operations, Systran Corp. in Dayton, Ohio, used its SCRAMNet replicated shared-memory network to place as many as 8 Mbytes of identical computer-addressable memory in each network computer node. Changes in the memory of one computer then go to all memories on the network via fiber optic cable within microseconds. Arnold officials report that after this modification inter-computer transfers of even the largest data blocks were occurring at speeds approaching those of the host computer bus. - J.R.

For more information, phone Systran at 513-252-5601, or fax 513-258-2729.

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