Simulating the DIRCM engagement: component and system level performance

Abstract

The proliferation of a diversity of capable ManPADS missiles poses a serious threat to civil and military aviation. Aircraft self protection against missiles requires increased sophistication as missile capabilities increase. Recent advances in self protection include the use of directed infrared countermeasures (DIRCM), employing high power lamps or lasers as sources of infrared energy. The larger aircraft self-protection scenario, comprising the missile, aircraft and DIRCM hardware is a complex system. In this system, each component presents major technological challenges in itself, but the interaction and aggregate behaviour of the systems also present design difficulties and performance constraints. This paper presents a description of a simulation system, that provides the ability to model the individual components in detail, but also accurately models the interaction between the components, including the play out of the engagement scenario.Objects such as aircraft, flares and missiles are modelled as a three-dimensional object with a physical body, radiometric signature properties and six-degrees-of-freedom kinematic behaviour. The object's physical body is modelled as a convex hull of polygons, each with radiometric properties. The radiometric properties cover the 0.4-14 µm spectral range (wider than required in current technology missiles) and include reflection of sunlight, sky radiance, atmospheric effects as well thermal self-emission. The signature modelling includes accurate temporal variation and spectral descriptions of the object's signature. The object's kinematic behaviour is modelled using finite difference equations. The objects in the scenario are placed and appropriately orientated in a three-dimensional world, and the engagement is allowed to play out.Low-power countermeasure techniques against the missile seekers include jamming (decoying by injecting false signals) and dazzling (blinding the sensor). Both approaches require knowledge of the missile sensor and/or signal processing hardware. Simulation of jamming operation is achieved by implementing the missile-specific signal processing in the simulation (i.e. accurate white-box modelling of actual behaviour). Simulation of dazzling operation is more difficult and a parametric black-box modelling approach is taken. The design and calibration of the black-box dazzling behaviour is done by heuristic modelling based on experimental observations. The black-box behaviour can later be replaced with verified behaviour, as obtained by experimental laboratory and field work, using the specified missile hardware.The task of simulating a DIRCM system is scoped, by considering the threats, operational requirements and detailed requirements of the respective models. A description is given of the object models in the simulation, including key performance parameters of the models and a brief description of how these are implemented. The paper closes with recommendations for future research and simulation investigations.

IR Composite Image Generation by Wavelength Band Based on Temperature Synthesis Estimated from IR Target Signature and Background Scene

“…Also, the radiance intensities corresponding to the min and max gray level are obtained using Equation (2). The radiance intensities corresponding to the gray levels between the min and max gray levels can be obtained based on the proportional relationship of the radiance intensity and gray level, and then temperatures corresponding to the obtained radi-ance intensities for the gray levels between min and max gray levels are estimated using Equation (6). Then, the approximately estimated temperature is compensated by using the slope information of original temperatureradiance curve and the approximated one.…”

“…We can know that the radiance intensity for the temperature and the temperature estimation error have different characteristics for each WB. Figure 4 shows the original radiance curve L * ðTÞ and approximately estimated one LðTÞ according to arbitrary temperature.T represents the estimated temperature obtained from the radiance LðTÞ using Equation (6). The compensated temperatureT obtained using only the first order tangent slope of L * ðTÞ forT is as follows:…”

“…Due to easy investigation and cost reduction in principle establishment and performance evaluation for functionality of an IR system, the demand for IR simulators is quickly increasing for military purpose research. Recent military IR simulators such as IR countermeasures (IRCM), directed IRCM (DIRCM), and IR reticle seeker are broadly used for evaluation, efficiency, and modification for actual military IR sensor systems [1][2][3][4][5][6][7][8]. The basic materials for analyzing arbitrary IR system are IR target and background images which are transformed as IR signatures with an intensity (gray-level) distribution corresponding to the temperature range of the IR target and background scene.…”

Review and prospects of optical countermeasure technologies

“…The development of effective OCM techniques and their implementation into a system to protect a platform requires the analysis of the platform's susceptibility of being engaged by a missile in a hostile environment, accurate modelling of the behaviour of a launched missile, the evaluation of target detection and tracking algorithms, and the analysis of the sur- III vivability of the platform once a damage has occurred. Several conference papers and references therein provide unclassified data and models based on elementary physics as a starting point for further analysis [13,14,15,16,17,18].…”

The effectiveness of amplitude modulation on the laser dazzling of a mid-infrared imager

“…In addition, others showed that in-band laser radiance on an uncooled thermal imager leads to thermal runaway, causing damage before a significant number of pixels are dazzled 12 . Simulations of the interaction of laser dazzle with imagers are fundamental to gaining the most from experimental and trials data 13 . It is also vital to understand the impact of the focal plane array integration on the extent of laser dazzle 14 .…”