As a bonus, the random code's continuous signal provides precise information about the time.

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Later, Inspector General Glenn Fine and his investigators discovered at least 17 other documents loaded with top secret signal information and code words that Gonzales had mishandled in violation of Justice Department rules and potentially in violation of federal criminal laws.

NPR: Report: Ex-AG Gonzales Mishandled Classified Info

They could be used to make cheap radio-frequency identity tags in essence, printable bar-codes that transmit an identifying code in response to a pulsed radio signal.

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In the future, we hope that a global army of open-source code developers, students and other experts in digital signal processing, as well as citizen scientists willing to lend their intelligence to our exploration, will have access to the same technology and join our quest.

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Pulse-code modulation is simply a way of representing the analog electrical signal, in digital form.

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