title: Integrated target tracking and weapon guidance
Creators: name: Davies, James
Publisher: name: University of Liverpool Repository
Year: 2013

description: The requirements of a modern guided weapon will be established based on the current and perceived threats at the time the design is commissioned. However the design of a modern guided weapon is a long and expensive process which can result in the weapon entering service only for the original threat to have changed or passed, inevitably inducing a capability gap. The defence budgets of the major military powers such as the UK and USA continue to shrink. As a result the emphasis of military research is being placed on adapting current legacy systems to bridge these capability gaps. One such gap is the requirement to be able to intercept small relocatable, highly manoeuvrable targets. It was demonstrated a number of years ago, that the performance of a legacy weapon against manoeuvering targets could be potentially increased by retrofitting a data link to the weapon. The data link allows commands to be sent to the weapon in flight. The commands will result in the weapon executing one or more manoeuvres which will change the shape of the trajectory. This has the potential to improve the performance of current Advanced Anti-Armour Weapons (AAAW) against manoeuvring targets. The issue which arises from data linking any weapon including an AAAW, is that the ability to shape the trajectory of the weapon will be limited due to the original design parameters of the non data linked system. Therefore in order to obtain the maximum performance increase, the trajectory shaping (retargetting) capability must be efficiently utilised over the duration of the weapon fly out. It was postulated in this thesis that this could be achieved using an integrated fire control system, which would seek to calculate an optimal shaped trajectory. The optimal trajectory should maximise the ability of the weapon to respond to target manoeuvres, thereby improving the probability of a successful intercept occurring. The potential effectiveness of an integrated fire control system was explored by considering the scenario of a generic data linked AAAW which is to intercept a small highly manoeuvrable surface vessel. A total of three integrated fire control systems were developed which calculated the optimal trajectory for different criteria. The first system optimised the weapon trajectory considering multiple predicted target trajectories. Each trajectory had an associated probability. For a given weapon trajectory, the seeker would be able to detect the target at one or more locations along certain predicted target trajectories. The sum of the probabilities associated with the detectable locations represented the total probability of intercept. The weapon trajectory was optimised by calculating the trajectory which achieved the maximum probability of intercept using simulated annealing and simple search optimisation algorithms. The second system optimised the weapon trajectory considering only the most probable trajectory (M.P.T) from a distribution of predicted target trajectories. Appropriate commands were calculated such that a location along this M.P.T trajectory was detectable at some instant in time. The third system presented in this thesis optimised the trajectory considering the maximum probability of intercept initially and then only the M.P.T trajectory later on in the engagement. The three integrated systems and a Fire and Forget system were tested against 80 random target trajectories. In each of the integrated fire control systems, the performance of the AAAW against manoeuvring targets was significantly improved when compared to the Fire and Forget results.