![]() This website is developed as a part of the world's largest public domain archive,, and not developed or endorsed by the U.S. law and are therefore in the public domain. Most radars on aircraft are mounted facing forward and can see in a cone shape area. National Archives and DVIDS is "a work prepared by an officer or employee" of the federal government "as part of that person's official duties." In general, under section 105 of the Copyright Act, such works are not entitled to domestic copyright protection under U.S. Side looking radar is typically only carried on US reconnaissance aircraft. All of these materials are preserved because they are important to the workings of Government, have long-term research worth, or provide information of value to citizens.ĭisclaimer: A work of the U.S. The Defense Visual Information Distribution Service provides a connection between world media and the American military personnel serving at home and abroad. There are approximately 10 billion pages of textual records 12 million maps, charts, and architectural and engineering drawings 25 million still photographs and graphics 24 million aerial photographs 300,000 reels of motion picture film 400,000 video and sound recordings and 133 terabytes of electronic data. When you have loaded and viewed radar data in radar chooser mode in the primary window, you may store it in a side window just like any other type of data by. NARA keeps those Federal records that are judged to have continuing value-about 2 to 5 percent of those generated in any given year. National Archives and Records Administration (NARA) was established in 1934 by President Franklin Roosevelt. National Archives and Defense Visual Information Distribution Service. Mobile and telecommunications industry: protecting humans from electromagnetic radiation.The objects in this collection are from The U.S. This design has the advantage that the holes in the substrate affect the resonance properties of the structured metallic layer and the spectral absorption of the whole device.įeatures and benefits include: very broad operation bandwidth (14 - 26 GHz) stable angular behaviour compared to homogeneous absorbers more degrees of freedom for designing thin absorbers a simple fabrication process, only one hole per unit cell is required and thin absorbers with reduced weight.ĭefence industry: tracking applications to reduce the radar cross section (RCS) of aircrafts or ships Įlectronic packaging and building industry: shielding electronic circuits, equipment and living environments from electromagnetic interference īuilding industry: absorption of incident radiation to buildings located around airports The ETH researchers have devised perforated FSS absorbers with improved absorptive properties, comprised of a perforated lossy substrate on one side and covered by a FSS pattern on the other side. ![]() While these absorbers are usually much thinner than other types of absorber, they still suffer from narrow bandwidths, More recently, absorbers based on frequency selective surfaces (FSS) have been proposed. However, such absorbers are usually narrow band and are quite bulky. ![]() Planar absorbers are of special interest because of they are suitable for use in a range of different devices and environments. Radar absorbers for minimising the reflection of incident electromagnetic waves come in a variety of different formats, including pyramidal absorbers, Salisbury screens, Jaumann absorbers and Planar absorbers. Researchers at ETH Zurich have developed a new type of radar absorber with improved absorptive properties. ![]()
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