Martin Norsell

Bio: Martin Norsell is an academic researcher from Swedish National Defence College. The author has contributed to research in topics: Radar cross-section & Radar. The author has an hindex of 7, co-authored 21 publications receiving 136 citations. Previous affiliations of Martin Norsell include Royal Institute of Technology.

Aircraft Trajectory Optimization with Tactical Constraints

Abstract: Aircrafttrajectory optimization is traditionally used forminimizing fuel consumption or time when going from one flightstate to another. This thesis presents a possible approach toincorporate tactical constraints in aircraft trajectoryoptimization. The stealth technology of today focuses on making thetactics already in use more effective. Since tactics andstealth are closely interrelated, new and better results may beobtained if both aspects are considered simultaneously. Simplyreducing the radar cross section area in some directionswithout considering tactical aspects may result in little, ifany, improvement. Flight tests have been performed in cooperation withEricsson Microwave Systems and the Swedish Air Force FlightAcademy. The aircraft used was the subsonic jet trainer Saab105, designated SK60 by the Swedish Air Force. The results showa decrease of 40% in the time interval between the instant theaircraft was first detected until it could pass above the radarstation. This corresponds to a reduced radar cross section(RCS) in the direction from the aircraft to the radar of almost90%, if classical RCS reduction techniques would have beenapplied. If a modern aircraft with stealth properties would be used,the proposed methodology is believed to increase the possibleimprovements further. This is because the variation of themagnitude of RCS in different directions is greater for a shapeoptimized aircraft, which is the property exploited by thedeveloped method. The methods presented are indeed an approach utilizing theideas of the network centric warfare (NCW) concept. Themethodology presented depends on accurate information about theadversary, while also providing up-to-date information to theother users in the information network. The thesis focuses on aircraft but the methods are generaland may be adapted for missiles, shipsor land vehicles. Theproposed methods are also economically viable since they areuseful for existing platforms without costly modifications. Themethods presented are not limited to radar threats only. Thereasons for using radar in this thesis are the availablenon-classified data and that radar is known to pose a majorthreat against aircraft.

Probabilistic risk assessment for integrating survivability and safety measures on naval ships

Abstract: Conflicts of today are characterized by both traditional and irregular tactics and by non-state actors making innovative use of modern technologies. These conditions set new demands on naval ships. The aim of this investigation is to describe how, based on probabilistic risk assessment, the concept of operation for a naval ship can be turned into safety scenarios to be used in the evaluation of risk. In this investigation, civilian state-of-the-art methods for probabilistic risk assessment are merged with the specific demands of naval ships. Relevant aspects of safety culture, codes, regulations and rules are analysed with respect to requirements on safety scenarios, and military operational research with respect to modelling military systems. The results show that the scenarios must have calculable probability and must be adapted to the vessel in question. Results from simulations show that modelling operational tasks is one way to support experts in the definition of safety scenarios.

Conservative RCS Models for Tactical Simulation

Abstract: This paper describes a procedure for generating conservative radar cross section (RCS) models able to meet the computational requirements imposed by simulation and related applications. The key concept is to downsample calculated or measured RCS data retaining local extreme values; thus, a conservative RCS matrix is obtained. Spline approximations are used in order to obtain continuity in the RCS models. RCS models with varying resolution have been generated and analyzed, and it is shown how spatial Fourier transforms can be used when determining feasibility for certain decision making applications. Furthermore, it is found that the interpolation errors obtained from the conservative RCS models are well described by generalized extreme value theory.

Models and computational algorithms for maritime risk analysis: a review

Abstract: Due to the undesirable implications of maritime mishaps such as ship collisions and the consequent damages to maritime property; the safety and security of waterways, ports and other maritime assets are of the utmost importance to authorities and researches. Terrorist attacks, piracy, accidents and environmental damages are some of the concerns. This paper provides a detailed literature review of over 180 papers about different threats, their consequences pertinent to the maritime industry, and a discussion on various risk assessment models and computational algorithms. The methods are then categorized into three main groups: statistical, simulation and optimization models. Corresponding statistics of papers based on year of publication, region of case studies and methodology are also presented.