Abstract: An optically transparent radar absorbing material has alternating layers of optically transparent conductive material with layers of even thickness of optically transparent material having a homogenous dielectric constant. The even thickness is one quarter of the wavelength of a targeted electromagnetic energy.

Abstract: A new asynchronous localization method for a network of nodes and transmitters, the position of at least one of the nodes and/or transmitters being known, involves receiving a first signal directly from a first transmitter at a first node of a first node pair, receiving the first signal relayed from a second node of the first node pair at the first node, and determining the delay at the first node between the direct and relayed first signal by comparing the direct and relayed first signals. This may be repeated with the first node acting as relay to determine the delay at the second node. Time difference of arrival and/or time of flight between first and second nodes may be determined using the determined delay at the first and/or second node and/or known node locations. The process is repeated for additional transmitters/node pairs until sufficient information is determined for desired applications.