Aspects of the design, evaluation and accuracy of airborne sensor clusters using time-difference of arrival

One way of improving situational awareness without increasing the risk of detection is to use passive sensor systems. If this capability is provided by several aircraft in a cluster, which can incorporate small basic sensor platforms, advantages can be gained such as longer baselines and an increased number of sensors in the cluster. In this paper, a methodology is presented that links results from signal processing to a Design Space Exploration, DSE, regarding sensor clusters when designing clusters that can operate both independently and in cooperation with other systems. When using Time-Difference of Arrival, the accuracy of the estimated location of a signal source depends on errors in timing and positioning of the sensors, errors in estimating signal arrival times and number of sensors and their spatial distribution. The Cramer-Rao Lower Bound is used to investigate the accuracy of signal source estimates for five different clusters and two levels of timing and positioning accuracy. The results show that the direction of arrival estimates are more accurate than those for the range. Although more sensors generally increased the accuracy, their spatial distribution and baseline related to the distance to the signal source also influence the quality of the results. The DSE process is supported by the collected presentation of the data regarding the measurement accuracy of the different sensor configurations, incorporating both cluster configuration as well as the positioning and timing. Having readily accessible data, the decision makers can focus on choosing the sensor system that meets the operational needs. (C) 2019 Elsevier Masson SAS. All rights reserved.