Toward intelligent sensors - reliability for time delay based direction of arrival estimates

Abstract

Increasing demand for automatic large area surveillance has made methods estimating direction of arrival (DOA), especially acoustic methods, an interesting topic. In these systems false alarms and faults are a disturbing factor. This paper presents a reliability criterion and a new method to diminish these errors. In very low signal-to-noise ratio conditions there arc seldom any means to improve the performance of a DQA estimator. In these cases it is important to have some information about the estimation reliability. Our focus is on wideband signals propagating as planar waves in three dimensional space. If the estimation method makes no assumptions on the signal propagation speed, it is possible to compute a reliability measure for obtained estimates. With this reliability measure we are able to decide whether the data produced by a time delay based DQA estimation system is usable or not. Indeed, with this criterion an estimation system can state its own reliability.

Round Trip Delay Time as a Linear Function of Distance Between the Sensor Nodes in Wireless Sensor Network

“…This will introduce errors into the RTD time estimates. A brief analysis of RTD time errors can be found in [6]. This paper is arranged into five sections including introduction.…”

Veiled Politics: Muslim Women’s Visibility and Their Use in European Countries’ Political Life

“…This will introduce errors into the RTT estimates. A brief analysis of RTT time errors can be found in [18]. …”

“…The network requires more than 3 RipEX unit nodes to form a round trip time. The minimum number of RipEX unit nodes required to form RTT path are 3 [8][9][10][11][12][13][14][15][16][17][18][19] and maximum RipEX unit nodes in round trip time paths should not be more than (N-1).This will put the limits on the RipEX unit nodes used in round trip time path. This limit of RipEX unit nodes in RTT path for Wireless network with 'N' RipEX unit nodes is as following:…”

Comparison of three post-processing methods for acoustic localization

“…A single point-like sound source emitted white noise in free field as described in 11 . The acoustic data was ray traced to the eight microphones of two spatially separated arrays.…”