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MADRE over-the-horizon radar at the NRL's Chesapeake Bay Detachment U.S. Navy Relocatable Over-the-Horizon Radar station. The most common type of OTH radar, OTH-B (backscatter), [3] uses skywave or "skip" propagation, in which shortwave radio waves are refracted off an ionized layer in the atmosphere, the ionosphere, and return to Earth some distance away.
In physics, backscatter (or backscattering) is the reflection of waves, particles, or signals back to the direction from which they came. It is usually a diffuse reflection due to scattering , as opposed to specular reflection as from a mirror , although specular backscattering can occur at normal incidence with a surface.
Radar cross-section (RCS), denoted σ, also called radar signature, is a measure of how detectable an object is by radar. A larger RCS indicates that an object is more easily detected. [1] An object reflects a limited amount of radar energy back to the source. The factors that influence this include: [1] the material with which the target is made;
The coordinate system is defined from the viewpoint of the wave source, before and after scattering. The BSA is most commonly used in radar, specifically when working with a Sinclair Matrix because the monostatic radar detector and source are physically coaligned.
A radar scatterometer operates by transmitting a pulse of microwave energy towards the Earth's surface and measuring the reflected energy. A separate measurement of the noise-only power is made and subtracted from the signal+noise measurement to determine the backscatter signal power.
At angles other than the backscatter direction, the light intensity is subject to numerous essentially random fluctuations called speckles. This is one of the most robust interference phenomena that survives multiple scattering, and it is regarded as an aspect of a quantum mechanical phenomenon known as weak localization (Akkermans et al. 1986 ...
The group’s mission is to “develop a fully 3D weather radar that can accurately track the movement and growth process of cloud particles and large-scale weather fronts.”
Key to the operation of any backscatter radar is the ability to filter out the huge return from the ground and sea, and capture only the objects of interest. This is accomplished using the Doppler effect and gating out the vast majority of the signal. In the case of Cobra Mist, the signal was first gated for range by eliminating any signals ...