In response to the needs of the UK MOD QinetiQ have designed, developed and trialled an ad-hoc, self organising network of acoustic nodes for in-depth deployment that can detect and track military targets in a range of environments and for all types of weapon locating. Research conducted has shown that disposable technologies are sufficiently mature to provide a useful military capability. Work this year has included a 3 month series of trials to exercise the prototype equipment and has provided an indication of in-service capability across a broad range of environments. This paper will discuss the scientific approach that was applied to the development of the equipment, from early laboratory development through to the prototype sensor network deployment in operationally representative environments. Highlights from the trials have been provided. New findings from the fusion of a low cost thermal imager that can be cued by the acoustic network are also discussed.
The cost of an unattended ground sensor system is based on two factors: the number of sensor nodes used and, the complexity of each sensor/communications node. The tracking accuracy of the sensor network is a trade off between the density of the network and the accuracy with which the sensor nodes can determine the position or bearing of the target. Assuming acoustic sensors, the errors reduce, primarily, to timing errors, within each of the sensor nodes. Therefore that understanding the timing errors within a network of acoustic nodes is a factor in determining system cost for a given level of information fidelity. This paper explores the error mechanisms within and without each of the sensor nodes thus identifying the critical sub systems where engineering effort would be most effectively directed.
Acoustic sensors have been the primary sensor of choice for many UGS network concepts. This is primarily due to their low cost, non line of sight performance and the fact that most targets of interest are noisy. This paper explores the benefits to be gained by attaching additional sensors to an acoustic sensor network to provide extra information. A methodology is described to assess the cost of acquiring a certain level of information and this is used to explore the context in which the sensor network is operated. It is demonstrated that the optimum choice of sensors is dependent on the target set and the information required from the network. The potential benefits of a 'plug and play' sensor suite are examined in the context of using this concept for targeting.
The nature of many current Intelligence, Surveillance, Target Acquisition and Reconnaissance (ISTAR) sensor systems requires that they are controlled at an operational or strategic level. The trend towards asymmetric/urban warfare has created the necessity for tactical commanders to be empowered with a similar ISTAR capability but over a reduced area. The variable temporal, spatial and cost constraints imposed by each scenario requires an adaptable organic sensory system to be developed to support the tactical commander. Unmanned Disposable Organic Sensor Networks (DOSNs) are promising to provide sensory solutions in many tactical situations. However in order to develop a suitable DOSN it is necessary to identify the optimum realisation to meet the tactical commanders requirements. In this paper the work conducted by QinetiQ for elements of the UK MOD is discussed. This includes: 1) A method for assessing the value of each specific realisation of a DOSN against a range of scenarios. 2) Description of models used to generate an understanding of the capability of DOSN systems. 3) Description of an experimental DOSN system with associated trial results and plans to validate the models discussed above. The technical approach employed could also be used to assess the applicability of DOSN systems across a range of other military ISTAR requirements.
This paper describes the development of a tool that predicts the coverage and performance of sensor networks. Specifically it examines weapon locating radars and acoustic sensors in different terrain and weather conditions. The computer environment and multiple sensor models are presented. Fusion of sensors takes multiple predicted accuracy metrics from the single sensor performance models and combines them to show networked performance. Calculations include Cramer-Rao lower bound computation of the sensors and the fused sensors source location error. Results are presented showing the outputs of the models in the form of sensor accuracy maps superimposed onto terrain maps.
Major advances in base technologies of computer processors and low cost communications have paved the way for a resurgence of interest in unattended ground sensors. Networks of sensors offer the potential of low cost persistent surveillance capability in any area that the sensor network can be placed. Key to this is the choice of sensor on each node. If the system is to be randomly deployed then non line of sight sensor become a necessity. Acoustic sensors potentially offer the greatest level of capability and will be considered here. In addition, there is a trade off between sensor density and tracking technique that will impact on cost. As a passive sensor, only time of arrival or bearing information can be obtained from an acoustic array, thus the tracking of targets must be done in this domain. This paper explores the critical step between array processing and implementation of the tracking algorithm. Specifically, unlike previous implementations of such a system, the bearings from each frequency interval of interest are not averaged but are used as data points within a Kalman filter. Thus data is not averaged and then filtered but all data is put into the tracking filter.
Counter battery operations have traditionally relied upon weapon locating radar and long range acoustic detection to locate hostile systems, friendly artillery fire is then used to destroy the enemy. At short ranges the timelines are such that this can be achieved, however at longer ranges with extended flight times and reduced out of action times, the 'shoot and scoot' tactics of enemy systems, this process is not effective. This capability can be regained with forward deployed sensors which detect and track the enemy indirect fire systems both during and after firing. This paper explains how netted sensors working co-operatively can solve the system level problems of long range counter battery operations, to ensure that the munition engages the target. Results show that low cost sensors placed close to areas of interest can locate artillery targets with accuracies exceeding current more expensive detection systems. Once the target has been located and identified it may be tracked using the same sensor network. Updating the munition with these details will ensure successful engagement. Results will be shown demonstrating the location capability of a low cost netted sensor system against rockets, mortars and shells.