This paper studies the problem of determining the node locations in ad-hoc sensor networks. We compare three distributed localization algorithms (Ad-hoc positioning, Robust positioning, and N -hop multilateration) on a single simulation platform. The algorithms share a common, three-phase structure: (1) determine node–anchor distances, (2) compute node positions, and (3) optionally refine the p...

This paper investigates the problem of localizing submerged sensors and provides a new mechanism to determine the coordinates and bearing of those sensors using only one beacon node. In underwater wireless sensor networks (UWSN), precise coordinates of the sensors that actuate or collect data is vital, as data without the knowledge of its actual origin has limited value. Mostly, the multilatera...

GNSS (Global Navigation Satellite System) positioning is not available underwater due to the very short range of electromagnetic waves in sea water medium. In this article a LBL (Long Base Line) acoustic repeater system presented. The hyperbolic, i.e., based on time differences and it does need accurate atomic clocks synchronize repeaters. architecture calculations that demonstrate feasibility ...

This report presents R2DM (Raw Ranging Data Management) and PDM (Processed Data Management) services. R2DM service is a web service developed for storing, managing and accessing the raw data from indoor localization benchmarking experiments. By raw ranging data we mean the measured physical values used as input for the localization algorithms, such as Angle of Arrival (AoA), Time of Arrival (To...

In this paper, obtaining time of arrival (TOA) measurements in a sensor network is investigated. Differentiating these TOA measurements provides the Time Difference of Arrival (TDOA) measurements between sensor pairs. An approach is proposed to estimate the TOA at a single sensor in a semi-passive scenario. The theoretical investigation is supported by field trials. This experimental analysis p...

Estimation of Time Difference of Arrivals (TDOAs) corresponding to early room reflections can be formulated as a Blind Channel Identification (BCI) problem, exploiting signals acquired by a set of microphones, given an unknown transmitted source. To cope with the intrinsic noise sensitivity and ill-posedness of the problem, sparsity and nonnegativity priors on the Acoustic Impulse Response (AIR...

We present two novel approaches for the problem of selfcalibration of network nodes using only TDOA when both receivers and transmitters are unsynchronized. We consider the previously unsolved minimum problem of far field localization in three dimensions, which is to locate four receivers by the signals of nine unknown transmitters, for which we assume that they originate from far away. The fir...