Abstract: A polarizer screen for a satellite communications terminal, comprising a plurality of layers separated by dielectric material, each layer having a grid of parallel metal strips and a periodic distribution of interleaved metal dipoles, wherein a first set of dipoles is arranged to be perpendicular to the metal strips and a second set of dipoles is arranged to be parallel to the metal strips such that any linearly polarized electromagnetic waves that pass through the screen are converted into orthogonal circular polarization in different frequency bands.

Abstract: Systems and methods involve the extension of the well known technique of virtual reality to encompass the use of virtual or real sensors as a means of detecting virtual threats including mines and improvised explosive devices in complex threat environments and to allow fully immersive computer based basic training, pre-deployment training or mission specific training. The disclosed systems and methods also allow the development of techniques, tactics and procedures in a representative environment to improve the effectiveness of operations and to explore a range of scenarios which might be experienced in real life by an individual or a group of personnel using sensors including both handheld sensors and sensors mounted on machines including robotic platforms to detect the presence of threats.