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The scale of dBZ values can be seen along the bottom of the image. dBZ is a logarithmic dimensionless technical unit used in radar. It is mostly used in weather radar, to compare the equivalent reflectivity factor (Z) of a remote object (in mm 6 per m 3) to the return of a droplet of rain with a diameter of 1 mm (1 mm 6 per m 3). [1]
Reflective array 'billboard' antenna of the SCR-270 radar, an early US Army radar system. It consists of 32 horizontal half wave dipoles mounted in front of a 17 m (55 ft) high screen reflector. With an operating frequency of 106 MHz and a wavelength of 3 m (10 ft) this large antenna was required to generate a sufficiently narrow beamwidth to ...
Planar reflectarray fed by a horn antenna.Structure showing unit cells. [1] This antenna has fixed cell delays, configured by different cutout sizes in each cell, as can be seen in the top-right inset.
In those situations, it is useful to use a related quantity called the normalized radar cross-section (NRCS), also known as differential scattering coefficient or radar backscatter coefficient, denoted σ 0 or σ 0 ("sigma nought"), which is the average radar cross-section of a set of objects per unit area:
A corner reflector for radar testing. A corner reflector is a retroreflector consisting of three mutually perpendicular, intersecting flat reflective surfaces. It reflects waves incident from any direction directly towards the source, but translated.
The experimental Morgenstern German AI VHF-band radar antenna of 1943–44 used a "double-Yagi" structure from its 90° angled pairs of Yagi antennas formed from six discrete dipole elements, making it possible to fit the array within a conical, rubber-covered plywood radome on an aircraft's nose, with the extreme tips of the Morgenstern's ...
In the United States NEXRAD network some of these angles are .5, 1.45, 2.4, and 3.35 degrees with the radar having up to 14 angles when it is in Severe Mode. [ 1 ] [ 2 ] In the composite reflectivity product, the highest intensities among those available on the different angles above each point in the image will be displayed.
Radar echoes, showing a representation of the carrier. Pulse width also determines the radar's dead zone at close ranges. While the radar transmitter is active, the receiver input is blanked to avoid the amplifiers being swamped (saturated) or, (more likely), damaged.