Showing papers on "Wireless sensor network published in 1986"

Distributed Tracking in Distributed Sensor Networks

Abstract: A distributed sensor network (DSN) consists of a set of processing nodes collecting data from sensors. When the nodes communicate, each node fuses the information received from other nodes with the local information to update its estimate on the state of the world. Previous papers have dealt with the theoretic algorithms for tracking multiple targets using a DSN. This paper considers the processing functions performed by each DSN node and presents some simulation results on tracking vehicles moving over a road network.

Joint probabilistic data association in distributed sensor networks

Abstract: A distributed multitarget tracking problem is considered. The joint probabilistic data association (JPDA) algorithm, which has been successfully used for tracking multiple targets in a cluttered environment, assumes a centralized processing architecture. It assumes that measurements are transmitted to a central site and processed. In some applications, however, it may be desirable for the sensor measurements to be processed at or near the sensors instead of transmitting them to the central processor. The local processed results are then sent over a communication network to be used by other processors. This paper presents a distributed version of the JPDA algorithm which is applicable under such a situation.

Distributed Sensor Networks

Abstract: : This report summarizes Distributed Sensor Networks research conducted during the period 1 April through 30 September 1978. One specific model for function decomposition and distribution is presented. A top level design of a strawman DSN for detecting and tracking low flying aircraft is described. High resolution acoustic signal processing algorithms for the strawman are specified and sized. Additional features of a multisite target search algorithm are presented. A moderately detailed model for simulation of an acoustic node under various scenarios is developed. New model simulation and experimental data analysis software are described and demonstrated. Technical issues involved with and plans for a digital acoustic data acquisition system are presented.

Fiber-Optic Sensors for Networks

Abstract: A major thrust for a larger scale introduction of fiberoptic sensors may be triggert by the need of installing increasing numbers of sensors in optically wired systems such as automated factories, mines, offshore platforms, ships, aircrafts, locomotives, automobiles, energy distribution systems etc. Here the sensors which may be discretely or continuously distributed in space are aimed to be operated and controlled by a central transceiver unit. They thus form what is called a sensor network.

Optical Fibre Distributed Sensors And Sensor Networks

Abstract: The paper reviews properties of distributed optical fibre sensors and techniques for passive multiplexing of multiple sensors on to a single optical fibre distribution network. A range of topologies for optical fibre networks associated with sensor multiplexing are discussed together with their limitations and advantages. These are then related to the modulation schemes of the light source and associated signal processing. The discussion covers pulse and FM schemes, sub-carrier modulation and synthetic pulse concepts. 1. INTRODUCTION Two previous papers[l,2] have drawn attention to the analogy between the classical theory of radar systems and the use of modulated lasers for the production of distributed sensors and for multiplexing multiple sensors on to a single data highway. Radar systems use the parameter of time delay to separately access signals from different targets located in space whereas distributed and multiplexed sensor systems can use the same parameter to identify sensing elements within a network of fibre sensors or input stimuli to a distributed sensor along a single fibre run. Various workers[3] have described a range of networks and modulation schemes for multiple sensors which bear interesting resemblances to radar techniques and the availability of single mode laser diodes which are capable of frequency chirping has produced a substantial interest in the technique of FM ranging[4] which has a very long history in the radar literature. The increasing range of optical components coupled with with the growing interest in distributed sensors emphasizes the need to examine the radar analogy closely and to ensure that the potential areas of transfer of ideas should be fully exploited.This paper reviews the above analogy in two complimentary ways. First it looks at the range of different topologies of fibre system that can be used for distributed and multiplexed sensors and draws some general conclusions on their performance and dependence on developments in fibre components. Secondly, it looks at signal processing schemes in terms of modulation of the primary light source in order to resolve multiple sensors on the basis of time delays within the fibres or network.

Distributed Hypothesis Testing in Distributed Sensor Networks

Abstract: : This report presents research results on distributed situation assessment in distributed sensor networks (DSNs). Information fusion algorithms for hypothesis formation and evaluation are presented. The algorithms are based on the concept of an information graph and issues that only consistent hypotheses are formed and information is not used redundantly. DSNs where the nodes have sensors observing different attributes are also considered. A theory for tracking groups of targets has been developed based on a Bayesian Theory for multitarget tracking. The general approach is used to develop algorithms for tracking with various types of sensors including acoustic. Some simulation results are presented. Keywords include: Distributed sensor networks; Distributed estimation, Distributed multitarget tracking; Information fusion; Group tracking; Distributed system testbed design; Acoustic tracking; and Attribute-based tracking.