The detection and tracking of UAV’s is a critical task for public and military security. The main are the low flight height and the small radar cross section (RCS). The problems increase in an urban environment with many high buildings, especially when tall buildings block the line of sight. A new concept of distributed radar sensors was developed to close this gap. To reduce the impact of radar shadows in urban canyons, a surveillance grid of optical and radar sensors is necessary which covers the complete urban environment. The radar sensors build up different security sectors and monitor all access routes for attacking UAVs. Sophisticated cameras which offer night vision capabilities complete the sensor network to reduce the false alarm rate through these regular, declared UAV flights. Cameras allow the integration of a man in the loop which has the final responsibility to define a target as a threat or not. The system supports the operator with a database which based on optical and radar signature of most commercially available UAV’s.
A high resolution imaging millimetre wave SAR delivers three key parameters important for precision farming
applications, namely range, reflectivity and polarization state. The reflectivity gives information upon the type of crop
and its humidity. Especially in the millimeter wave region young growing green plants exhibit a considerably higher
reflectivity than older, dry leaves. Dependent on the transmit-receive polarization also indications are given upon the
humidity of the underlying soil. Polarimetry also allows to judge the ripeness of the grain as the geometry of the ear is
changing during the ripening process.
The characterization of materials in the millimeter wave frequency range offer many new applications for quality control and security applications. This paper shows results for different applications with a real aperture scanning system in the frequency range between 75 GHz - 325 GHz in amplitude and phase.