NASA uses Snaggletooth for voice compression

Officials at Lockheed Martin in Houston, Texas wanted a low-cost digital signal processing board (DSP) for the NASA Neurolab experiment aboard the Space Shuttle Columbia`s flight STS-90.

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NASA uses Snaggletooth for voice compression

Officials at Lockheed Martin in Houston, Texas wanted a low-cost digital signal processing board (DSP) for the NASA Neurolab experiment aboard the Space Shuttle Columbia`s flight STS-90.

The single-board DSP is to perform high-speed multi-channel compression and decompression for the main voice recording mechanism of the Virtual Environment Generator (VEG) on Neurolab. The SHARC-based Snaggletooth, a 40 MHz DSP board from BittWare Research Systems in Concord, N.H., met their needs.

Lockheed Martin designers chose the BittWare Snaggletooth DSP board because it was the only solution available that could achieve multi-channel compression and decompression at a 4-kilobit-per-second data rate, says Trent Mills, Lockheed Martin`s VEG Systems Project Leader.

"We specifically needed a board with an on-board DSP to offload the compression tasks from the host processor," Mills explains. "Plus, BittWare`s DSP and I/O experience lowered our costs with an off-the-shelf solution and reduced our risk by giving us proven technology backed by solid customer references."

Neurolab is a set of life-science experiments that use human subjects and laboratory animals for testing human adaptability to zero gravity.

The Neurolab Sensory Motor Experiment 136 will use the VEG system, a space-qualified 3D graphics processor, wide-field-of-view view helmet-mounted display, and joystick to create a controlled, interactive virtual environment.

Developed at Lockheed Martin, the VEG`s headset microphone tracks the astronaut`s comments and simultaneously archives and downlinks voice data to Earth in real-time.

BittWare`s Snaggletooth board, with an AMBE-1000(tm) Vocoder, provides the main voice-compression engine for the VEG and compresses at a constant bit rate of 4 kilobits per second. The vocoder comes from Digital Voice Systems Inc. in Tampa, Fla., a supplier of voice coding solutions used in most major satellite communications systems.

The VEG system configuration, based on an Intel 200 MHz Pentium Pro microprocessor with 256 megabytes of RAM, includes a 13-board passive backplane in a custom ruggedized drawer. BittWare`s Snaggletooth SHARC board is configured with an eight-channel analog audio I/O mezzanine with DVSI voice compression and 16 channels of digital I/O. - J.M.

For more information on the Snaggletooth and Bittware, contact Stacey Megalaitis by phone at 603-226-0404, ext. 534, by fax at 603-226-6667, by post at BittWare Research Systems, 33 N. Main Street, Concord, N.H., 03301, by e-mail at staceym@bittware.com, or on the World Wide Web at http://www.bittware.com.

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The SHARC-based Snaggletooth, a 40 MHz DSP board from BittWare Research Systems in Concord, N.H., is performing high-speed multi-channel compression and decompression for the main voice recording mechanism for the NASA Neurolab experiment.

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