Andrew Thaeler - Academia.edu (original) (raw)
Papers by Andrew Thaeler
Journal of Parallel and Distributed Computing, 2005
In this paper, we present time-based positioning scheme (iTPS), a purely localized location detec... more In this paper, we present time-based positioning scheme (iTPS), a purely localized location detection scheme for sensor networks with long-range beacons. iTPS relies on time difference of arrival (TDoA) of radio frequency (RF) signals measured locally at each sensor to detect range differences from the sensor to four base stations. These range differences are combined to estimate the sensor location through trilateration. iTPS is an improvement over TPS (Cheng et al., IEEE INFOCOM, 2004), which produces two ambiguous position estimates when sensors are close to any base station. iTPS substantially reduces the number of ambiguous estimates and can improve accuracy. Features of iTPS include low communication overhead for sensors, no requirements for time synchronization, low computational overhead due to simple algebraic operations, and high scalability. We conduct extensive simulation to test iTPS and compare it with TPS. The obtained results show that iTPS is an efficient and effective scheme for location discovery in sensor networks with long-range beacon stations.
Fault-tolerant target detection and localization is a challenging task in collaborative sensor ne... more Fault-tolerant target detection and localization is a challenging task in collaborative sensor networks. This paper introduces our exploratory work toward identifying a stationary target in sensor networks with faulty sensors. We explore both spatial and temporal dimensions for data aggregation to decrease the false alarm rate and improve the target position accuracy. To filter out extreme measurements, the median of all readings in the closed neighborhood is used to approximate the local observation to the target. The sensor whose observation is a local maxima computes a position estimate at each epoch. Results from multiple epoches are combined together to further decrease the false alarm rate and improve the target localization accuracy. Our algorithms have low computation and communication overheads. Simulation study demonstrates the validity and efficiency of our design.
Eurasip Journal on Wireless Communications and Networking, 2007
Fault-tolerant target detection and localization is a challenging task in collaborative sensor ne... more Fault-tolerant target detection and localization is a challenging task in collaborative sensor networks. This paper introduces our exploratory work toward identifying the targets in sensor networks with faulty sensors. We explore both spatial and temporal dimensions for data aggregation to decrease the false alarm rate and improve the target position accuracy. To filter out extreme measurements, the median of all readings in a close neighborhood of a sensor is used to approximate its local observation to the targets. The sensor whose observation is a local maxima computes a position estimate at each epoch. Results from multiple epoches are combined together to further decrease the false alarm rate and improve the target localization accuracy. Our algorithms have low computation and communication overheads. Simulation study demonstrates the validity and efficiency of our design.
In this paper, we present a novel timebased positioning scheme (TPS) for efficient location disco... more In this paper, we present a novel timebased positioning scheme (TPS) for efficient location discovery in outdoor sensor networks. TF'S relies on TDoA (Time-Difference-of-Arrival) of RF signals measured IocaUy at a sensor to detect range differences from the sensor t o three base stations. These range differences are averaged over multiple beacon intervals before they are combined to estimate the sensor loeation through trilateration. A nice feature of this positioning scheme is that it is purely localized: sensors independently compute their positions. We present a statistical analysis of the performance of TF' S in noisy environments. We also identify possible sources of position errors with suggested measures to mitigate them. Our scheme requires no time synchronization in the network and minimal extra hardware in sensor construction. TPS induces no eommunication overhead for sensors, as they listen to three beacon signals passively during each beacon interval. The computation overhead is low, as the location detection algorithm involves only simple algebraic operations over scalar values. TF'S is not adversely affected by increasing network size or density and thus offers scalability. We conduct extensive simulations to test the performance of TPS when TDoA measurement errors are normally distributed or uniformly distributed. The obtained results show that TPS is an effective scheme for outdoor sensor self-positioning.
We introduce and study the localization problem in large scale underwater acoustic sensor network... more We introduce and study the localization problem in large scale underwater acoustic sensor networks. Considering that depth information is typically available for underwater sensors, we transform the 3D underwater positioning problem into its two-dimensional counterpart via a projection technique. We then introduce a localization scheme specifically designed for large scale acoustic underwater sensor networks. The proposed localization scheme does not require time-synchronization in the network. This scheme relies on time-differences of arrival (TDoA) measured locally at a sensor to detect range differences from the sensor to three anchors that can mutually hear each other. We consider variations in the speed of sound and analyze the performance of the proposed scheme in terms of the number of localized nodes, location errors, and the number of reference nodes.
Journal of Parallel and Distributed Computing, 2005
In this paper, we present time-based positioning scheme (iTPS), a purely localized location detec... more In this paper, we present time-based positioning scheme (iTPS), a purely localized location detection scheme for sensor networks with long-range beacons. iTPS relies on time difference of arrival (TDoA) of radio frequency (RF) signals measured locally at each sensor to detect range differences from the sensor to four base stations. These range differences are combined to estimate the sensor location through trilateration. iTPS is an improvement over TPS (Cheng et al., IEEE INFOCOM, 2004), which produces two ambiguous position estimates when sensors are close to any base station. iTPS substantially reduces the number of ambiguous estimates and can improve accuracy. Features of iTPS include low communication overhead for sensors, no requirements for time synchronization, low computational overhead due to simple algebraic operations, and high scalability. We conduct extensive simulation to test iTPS and compare it with TPS. The obtained results show that iTPS is an efficient and effective scheme for location discovery in sensor networks with long-range beacon stations.
Fault-tolerant target detection and localization is a challenging task in collaborative sensor ne... more Fault-tolerant target detection and localization is a challenging task in collaborative sensor networks. This paper introduces our exploratory work toward identifying a stationary target in sensor networks with faulty sensors. We explore both spatial and temporal dimensions for data aggregation to decrease the false alarm rate and improve the target position accuracy. To filter out extreme measurements, the median of all readings in the closed neighborhood is used to approximate the local observation to the target. The sensor whose observation is a local maxima computes a position estimate at each epoch. Results from multiple epoches are combined together to further decrease the false alarm rate and improve the target localization accuracy. Our algorithms have low computation and communication overheads. Simulation study demonstrates the validity and efficiency of our design.
Eurasip Journal on Wireless Communications and Networking, 2007
Fault-tolerant target detection and localization is a challenging task in collaborative sensor ne... more Fault-tolerant target detection and localization is a challenging task in collaborative sensor networks. This paper introduces our exploratory work toward identifying the targets in sensor networks with faulty sensors. We explore both spatial and temporal dimensions for data aggregation to decrease the false alarm rate and improve the target position accuracy. To filter out extreme measurements, the median of all readings in a close neighborhood of a sensor is used to approximate its local observation to the targets. The sensor whose observation is a local maxima computes a position estimate at each epoch. Results from multiple epoches are combined together to further decrease the false alarm rate and improve the target localization accuracy. Our algorithms have low computation and communication overheads. Simulation study demonstrates the validity and efficiency of our design.
In this paper, we present a novel timebased positioning scheme (TPS) for efficient location disco... more In this paper, we present a novel timebased positioning scheme (TPS) for efficient location discovery in outdoor sensor networks. TF'S relies on TDoA (Time-Difference-of-Arrival) of RF signals measured IocaUy at a sensor to detect range differences from the sensor t o three base stations. These range differences are averaged over multiple beacon intervals before they are combined to estimate the sensor loeation through trilateration. A nice feature of this positioning scheme is that it is purely localized: sensors independently compute their positions. We present a statistical analysis of the performance of TF' S in noisy environments. We also identify possible sources of position errors with suggested measures to mitigate them. Our scheme requires no time synchronization in the network and minimal extra hardware in sensor construction. TPS induces no eommunication overhead for sensors, as they listen to three beacon signals passively during each beacon interval. The computation overhead is low, as the location detection algorithm involves only simple algebraic operations over scalar values. TF'S is not adversely affected by increasing network size or density and thus offers scalability. We conduct extensive simulations to test the performance of TPS when TDoA measurement errors are normally distributed or uniformly distributed. The obtained results show that TPS is an effective scheme for outdoor sensor self-positioning.
We introduce and study the localization problem in large scale underwater acoustic sensor network... more We introduce and study the localization problem in large scale underwater acoustic sensor networks. Considering that depth information is typically available for underwater sensors, we transform the 3D underwater positioning problem into its two-dimensional counterpart via a projection technique. We then introduce a localization scheme specifically designed for large scale acoustic underwater sensor networks. The proposed localization scheme does not require time-synchronization in the network. This scheme relies on time-differences of arrival (TDoA) measured locally at a sensor to detect range differences from the sensor to three anchors that can mutually hear each other. We consider variations in the speed of sound and analyze the performance of the proposed scheme in terms of the number of localized nodes, location errors, and the number of reference nodes.