A radar signal is an electromagnetic (EM) wave, and as such will travel at the speed of light in the atmosphere. If part of the space has different EM properties, then some of the wave will be reflected from that region.
Solid objects are the most conspicuous, but rain radarsees the changes in the atmosphere caused by the rain clouds.
One of the most remarkable uses for radar is to measure the wind profile behind an aircraft carrier - the place where the incoming planes approach their carrier.
For this, a very brief high energy acoustic pulse is sent out, and this will cause compressions and rarefactions in the air behind the carrier.
Amazingly (to me) these minute differences in the EM properties of this space can be picked up by a radar.
The carrier always steams into the wind (when active) and the wind flows along the deck, and drops down in the wind shadow behind the carrier. This is precisely where the incoming plane is aiming to land, and a 'down draft' at this point will not help his accuracy. Thus the knowledge of the wind profile is of great value to the flight controller and the incoming pilot.
The higher the reflectivity of an object, the more intense and defined its highlights will appear. Objects with low reflectivity will have softer and less pronounced highlights. Reflectivity influences how light interacts with the surface of an object, affecting the appearance of highlights.
Bat speed in cricket is typically measured using specialized instruments like speed guns or radar guns. These devices calculate the speed at which the bat is moving when it makes contact with the ball. The faster the bat speed, the more power and force can be generated in the shot.
Emissivity and reflectivity are inversely related properties of materials. Emissivity refers to how well a material emits thermal radiation, while reflectivity refers to how well it reflects thermal radiation. A material with high emissivity will have low reflectivity, and vice versa.
The property that reflects light is called reflectivity. This is the measure of how well a surface reflects light and is often described in terms of its reflectance or albedo. Smooth, shiny surfaces tend to have high reflectivity, while rough or dark surfaces have low reflectivity.
The mirror reflectivity affects the quality of the reflected image by determining how much light is reflected back. Higher reflectivity mirrors produce clearer and brighter images, while lower reflectivity mirrors may result in dimmer and less sharp images.
Reflectivity with radar is measured by sending out a pulse of microwave radiation and then analyzing the strength of the return signal. The strength of the return signal provides information on the amount of radiation reflected back to the radar unit, which can indicate the size, shape, and composition of the target. Reflectivity values are typically represented in units of decibels (dBZ) in meteorological radar applications.
From NOAA website:http://weather.noaa.gov/radar/radinfo/radinfo.htmlBase ReflectivityThis is a display of echo intensity (reflectivity) measured in dBZ (decibels of Z, where Z represents the energy reflected back to the radar). "Reflectivity" is the amount of transmitted power returned to the radar receiver. Base Reflectivity images are available at several different elevation angles (tilts) of the antenna and are used to detect precipitation, evaluate storm structure, locate atmospheric boundaries and determine hail potential.The base reflectivity image currently available on this website is from the lowest "tilt" angle (0.5°). This means the radar's antenna is tilted 0.5° above the horizon.The maximum range of the "short range" (S Rng) base reflectivity product is 124 nm (about 143 miles) from the radar location. This view will not display echoes that are more distant than 124 nm, even though precipitation may be occurring at greater distances. To determine if precipitation is occurring at greater distances, select the "long range" (L Rng) view (out to 248 nm/286 mi), select an adjacent radar, or link to the National Reflectivity Mosaic.Composite ReflectivityThis display is of maximum echo intensity (reflectivity) from any elevation angle at every range from the radar. This product is used to reveal the highest reflectivity in all echoes. When compared with Base Reflectivity, the Composite Reflectivity can reveal important storm structure features and intensity trends of storms.The maximum range of the "long range" (L Rng) composite reflectivity product is 248 nm (about 286 miles) from the radar location. The "blocky" appearance of this product is due to its lower spatial resolution on a 2.2 * 2.2 nm grid. It has one-fourth the resolution of the Base Reflectivity and one-half the resolution of the Precipitation products.Although the Composite Reflectivity product is able to display maximum echo intensities 248 nm from the radar, the beam of the radar at this distance is at a very high altitude in the atmosphere. Thus, only the most intense convective storms and tropical systems will be detected at the longer distances.Because of this fact, special care must be taken interpreting this product. While the radar image may not indicate precipitation it's quite possible that the radar beam is overshooting precipitation at lower levels, especially at greater distances. To determine if precipitation is occurring at greater distances link to an adjacent radar or link to the National Reflectivity Mosaic.For a higher resolution (1.1 * 1.1 nm grid) composite reflectivity image, select the short range (S Rng) view. The image is less "blocky" as compared to the long range image. However, the maximum range is reduced to 124 nm (about 143 miles) from the radar location.
On weather maps created with radar data, areas with higher reflectivity usually indicate greater rainfall intensity. Reflectivity is a measure of the amount of radar energy returned to the radar site, with heavier rain or larger water droplets reflecting more energy back towards the radar. Therefore, higher reflectivity values on a radar map typically correspond to areas experiencing heavier rainfall.
Anne I. Mackenzie has written: 'Measured changes in C-band radar reflectivity of clear air caused by aircraft wake vortices' -- subject(s): Aircraft wakes, Microwave devices, Microwave frequencies, Radar, Radar detection, Vortex motion, Vortices, Wakes (Aerodynamics)
Reflectivity measures the amount of radar energy that is reflected back to the radar from precipitation particles, such as raindrops or snowflakes. By analyzing reflectivity data, meteorologists can identify the intensity, type, and spatial distribution of precipitation, helping them predict storm severity and rainfall amounts. This information is crucial for creating accurate weather maps and forecasts, allowing for timely warnings and better understanding of atmospheric conditions.
Graphs or Radar
Radar cross section (RCS) is measured in square meters (m²). It quantifies how detectable an object is by radar, representing the effective area that reflects radar signals back to the source. A larger RCS indicates a greater ability to reflect radar waves, making the object more detectable.
The level of reflectivity on weather radar displays the amount of precipitation in a particular area. Meteorologists use this information to track the intensity of precipitation, identify severe weather patterns, and monitor the movement of storms.
Speed is measured by distance traveled divided by time taken. These radar guns measure exactly how far the ball goes within a time frame.Ê
Doppler radial velocity, rather than the usual base reflectivity scans.
Time to cover a measured distance, or a radar gun.
Yes, a Radar Bounded Weak Echo Region (RBWER) is typically associated with an updraft in a thunderstorm. The RBWER represents an area where precipitation is being lifted by the updraft, producing low reflectivity values on radar.