The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Modern underwater acoustic modems, in addition to receiving and transmitting data, can measure signal propagation time and evaluate the distance between the transmitter and the receiver. These capabilities can be exploited to support the synchronization of underwater acoustic sensor networks, where sensing and actuation must be coordinated across multiple nodes. However, the problem of accurate propagation...
Characteristics of an underwater acoustic channel, which hydro-acoustic modems of the S2C technology can measure and provide to upper layer protocols, were used for evaluation of several important communication metrics and so for evaluation of the modem performance under the actual channel conditions. Particularly, these channel characteristics were used for assessment of the delivery success related...
The deployment of underwater acoustic modems was designed to investigate the various effects of underwater acoustic channel onto propagation of hydro-acoustic signals and thus onto performance of hydro-acoustic data link. Data represented sequences of QPSK signals spread over broad frequency band (18–34 kHz) using sweep-spread carrier (S2C) technology. Transmissions were conducted with data rates...
Modern underwater acoustic modems, besides transmitting and receiving data, are capable for measuring signal propagation time and thus also for evaluation of the distance between the transmitter and the receiver. Such capabilities can be exploited for synchronization of underwater acoustic sensor networks, where sensing and actuation must be coordinated across multiple nodes. However such problem,...
When propagating in water, acoustic signals experience distortions and thus received signals can essentially distinct from those which were transmitted. Basic distortions originate from interference of multipath arrivals comprising random energies, phases and Doppler shifts. Assuming an underwater acoustic environment for middle and high telemetry frequencies as a channel with (in wide sense) stationary...
Ultra-short baseline (USBL) positioning systems and reliable data transfer systems for application on underwater vehicles have recently attracted significant interest. However, contemporary USBL transceivers and underwater acoustic modems operate separately in time and/or in different frequency bands. This paper presents a technical solution blending positioning and communication modes. Physical implementation...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.