Signal Conditioning, Data Telemetry, Command Signaling and Platform Positioning in Ocean Observing
Data telemetry is the transmission of data from remote observing platforms. Transmission from control station to platform, an additional ability afforded by two-way communication (Tx/Rx) systems, allows command signaling for adjustment of mission parameters. Autonomous navigation requires the capability to receive navigational positioning data from satellite systems such as GPS or from underwater acoustic beacons, or the use of onboard inertial navigation systems. Data from distributed sensor networks is transmitted through space and through the atmosphere via radio waves, through the water via acoustic means, through cables as current pulses, or as optical pulses through fiber-optic waveguides. Since seawater is largely opaque to radio signals, submerged ocean observing applications relying on satellite and cellular network communications for transmission must have alternate means of communication between the submerged platform and a surface relay platform, or must periodically reach the surface for data transmission. Data are transmitted via modulation of a carrier wave. Signal conditioning consists of amplification of the initial signal, signal filtering to minimize electronic noise, digitization, and eventual carrier signal modulation in preparation for transmission.
KeywordsSignal conditioning Analog to digital conversion Carrier modulation Data telemetry Command signaling Platform positioning
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