No abstract

The radar signature of power lines is of high importance in the design of systems for helicopter collision avoidance. Laboratory measurements have been reported previously, but field measurements at millimeter waves are missing. The present contribution describes measurements done in ground-based configuration with a real aperture scanning-beam radar operating simultaneously at 35 and 94 GHz. By scanning, an aspect angle interval of 60° was covered, including the broadside aspect. The narrow beam width allowed to discriminate between different wires separated horizontally. While these measurements were done under a very shallow incidence angle, assisting measurements were done with the same radar mounted into an aircraft using synthetic aperture radar techniques. The results for shallow and steep incidence are compared and show the significant influence of this parameter on the signature of the power line. Additionally the measurement results are compared with those from model calculations

This paper addresses an experiment that was carried out in the North Sea region in the area of the island of Sylt with the aim to study the influence of the maritime boundary layer (MBL) on the propagation of radar signals under low grazing angle geometry. The radar measurements were carried out with the highly versatile MEMPHIS radar operating in sea configuration at X, Ka and W band simultaneously. Concerning the oceanographic and atmospheric characterization, the WTD 71 was responsible for the collection of measurements with a sophisticated suite of sensors partly mounted on the research vessel Elisabeth Mann Borgese. Over a period of four days a valuable dataset was collected including clutter measurements under different geometrical configurations. In this contribution the focus is given to the propagation aspects where dedicated propagation runs were carried out each day

Abstract-This paper describes an experiment that was carried out in the North

In a world, where terrorism is threatening human life in particular that of those forces and civilian personnel who are involved in peace keeping and peace enforcing missions, the defence against snipers is a necessary safety demand. For this purpose sensor systems based upon various principles are in use and still under development. Among those acoustic and electro optical sensors are the most common ones; however their performance is very often limited with respect to their ability to cope with dust, fog and haze, especially in urban terrain. Notably here the millimeter wave radar could offer the additional advantage of small, light weight miniature sensors with the capability to fulfill the demands of an urban environment. As a first step to develop a millimeter wave radar system as a part a multi sensor approach, the signature characteristics of typical sniper projectiles have been investigated. RCS simulations have been conducted, which were validated by measurements under well controlled conditions. The paper gives results from this work and discusses the implications on the design of a respective sniper detection approach