Signatures
The analysis of the scattering behaviour (signatures) of man-made targets in their natural environment is the main topic in this group. Subtasks are the determination of the scattered field (Radar Cross Section, RCS) of a target, the influence of neighbouring objects, the quantification of propagation effects, the optimization of the radar system, and the identification of measures for target masking and camouflaging. The focus is on the development of computer programs for the numerical simulation of radar signatures (web page ‘Simulation of target scattering’). Because of the growing importance of bistatic systems the determination of bistatic signatures (web page ‘Research Project BISTRO‘) is an important task of the group. For validation purposes monostatic and bistatic RCS measurements (web page ‘Measurements of radar signatures’) on test objects and scaled targets are performed.
A way to reduce the computation time for complex targets is by replacing it with simple geometries valid for a restricted aspect angle range. The alternative geometries (web page ‘Alternative geometries of scattering targets’) consist of only a few canonical objects, but nevertheless closely reproduce the RCS values with considerably less computational effort.
The detection of a target on the ground is affected by the scattering behaviour of the surroundings. This contribution to the total scattered field is called clutter (web page ‘ Determination of detection probabilities of artificial objects in an arbitrary environment’) . In order to model clutter, simulation programs are being developed. Statistical and semi-empirical clutter models are used to compute the expected backscatter densities.
The signature of a target can be reduced by coating the surface with absorbing materials. The Signature Group operates measurement facilities for the experimental determination of complex attenuation values (web page ‘Electromagnetic properties of materials’) and the results are being used to assess and validate the RCS models mentioned above.
Projects and Tasks:
UCAV-2010:
The concept of UCAV (unmanned combat air vehicle) assumes an autonomously operating military aircraft. The low radar oberservability is, therefore, one of the most important features of a UCAV. The absence of a pilot leads to a greater design (shape, size, material composition) and mission (flight speed, trajectory) flexibility, which makes simulation of Radar Cross Section (RCS) of a UCAV a challenging task. The research group "Signatures" performs simulations of RCS of various UCAV configurations and prepares suggestions for reducing RCS through modification of shape and the material coating of the vehicles.
FFT (Fortschrittliche Flugkörper Technologien – Innovative Missile Technologies):
The influence of the complete propagation path between a target and the antenna of a radar seeking head mounted behind a missile radome is examined. Transmission attenuation measurements on several material samples in the microwave frequency range are performed.