This paper studies the positioning problem based on two-way time-of-arrival (TW-TOA) measurements in asynchronous wireless sensor networks. Since the optimal estimator for this problem involves difficult nonconvex optimization, we propose two suboptimal estimators based on squared-range least squares and least absolute mean of residual errors. The former approach is formulated as a general trus...

The accuracy of 60 GHz millimeter wave based indoor localization is mainly determined by the accuracy of the measurements employed. These measurements can be affected by the propagation environment, such as multipath fading due to a Non Line of Sight (NLOS) channel. To improve the localization accuracy, a new ranging algorithm for 60 GHz wireless systems is proposed based on Time of Arrival (TO...

Lightning discharge emits RF energy over a wide range of frequencies. During cloud to ground lightning, when high currents occur in previously ionized channels, the most powerful emissions occur in the Very Low Frequency range. VLF (very low frequency) refers to radio frequencies spectrum range of 3 kHz to 30 kHz. Detection of lightning makes it possible to avoid various harmful effects occurri...

In this paper, we derive and analyze cooperative localization bounds for endoscopic wireless capsule as it passes through the human gastrointestin (GI) tract. We derive the Cramer-Rao lower bound (CRLB) variance limits on location estimators which use measured received signal strength(RSS) and ranging error limits using time of arrival (TOA). Using a three-dimension human body model from a full...

Since histogram-based methods are formed by some simple differences, they are very desirable for deinterleaving. However, their main imperfection concerns recognizing complex pulse repetition interval (PRI) patterns like jittered and staggered ones. In this paper, we present new thresholds to detect jittered and staggered PRI from histogram-based methods even in complex circumstances such as no...

A method for the direct outdoor localization of multiple impulse acoustic sources by a distributed microphone array is proposed. This problem great interest gunshot, firecracker and explosion detection in civil environment, as well gun, mortar, small arms, artillery, sniper military battlefield monitoring systems. Such kind complicated technical many aspects. In such scenario, permutation arriv...

In this paper, we address the problem of delay attacks on radio frequency time of arrival (ToA) secure ranging. In secure ranging, two mutually trusted devices try to determine their distance in the presence of an attacker. A delay attack consists of delaying the ranging messages exchanged between the devices, resulting in an increase of the measured message arrival times and thus in an increas...

All known time of arrival (TOA) deinterleaving algorithms have great diiculty separating interleaved radar pulse trains when two or more of the trains are significantly jittered. Such scenarios tend to lead to overwhelming ambiguity and fragmentation diiculties when using traditional techniques. In this report we propose a modiied sequence search technique combined with a novel recursive neural...

High-accuracy pulse repetition interval (PRI) estimation is meaningful for passive sensors to identify radar emitters. This paper considers the problem of estimating the PRIs of motionless radars in moving passive sensor systems. A modified method which based on observation calibration is proposed. This method can efficiently compensate the estimation bias induced by model mismatch, through cal...

<span lang="EN-US">Ultra-wideband (UWB) ranging via time-of-arrival (TOA) estimation method has gained a lot of research interests because it can take full advantage UWB capabilities. Energy detection (ED) based TOA technique is widely used in the area due to its low cost, complexity and ease implementation. However, many factors affect performance ED-based methods, especially, non-line-o...