radar wavelength and frequency

It only takes a minute to sign up.I am wondering if there is a general rule of thumb in the radar world for what frequency you should pick to detect targets of a certain size.For instance, if one had two radars set up - one for detecting targets of 5cm and one for detecting targets of 500m - what frequencies would be best?I understand that many more factors will go into this like surface roughness, etc but I would like to understand the rough relationship between carrier frequency and target size. Each antenna element must have a delay, or phase adjustment, such that after this adjustment, all elements will have a common phase of the signal. The minimum antenna size is proportional to wavelength and inversely proportional to frequency. When this technique is combined with Similarly, the use of a cosine pulse profile has an even more marked effect, with the amplitude of the sidelobes practically becoming negligible. Discuss the workings and policies of this site

CountTo10, it's not clear to me why though - that's why I asked! The “focusing” ability of the antenna is often described using an antenna lobe diagram, which plots the directional gain of an antenna over the azimuth (side to side) and elevation (up and down).The range of the radar system is also influenced by the choice of frequency. Radar works well in dirty and dusty environments and does not require any miner wearable component (MWC); however, it is only useful in line-of-sight applications and cannot differentiate between objects and humans.The test equipment presented in this chapter is used to study the reliability of microwave power transistors for the L frequency band for radar applications.

Therefore, a higher frequency also allows the beam to be more tightly focused for a given antenna size. When this was discovered, the band was divided into Ka, for “above” and Ku for “under,” the frequencies where radar operation is limited due to water vapor absorption. L band radars are mostly used for clear air turbulence studies. Note that for radar wavelengths much less than the diameter of the sphere, RCS is independent of frequency. By applying a bird filter to the existing extensive network of weather radar systems, real-time information on bird flight movements can be achieved.

250 - 500 MHz. The vertical axis is twice the ratio of power scattered from a homogeneous sphere of water to the power one calculates assuming ray theory.

Consider the following example : if the radar antenna is located at around 15 m above sea level, then the distance to the horizon is pretty close, (perhaps 15 km).

Water vapor, in particular, has high absorption in the “K” band. Reset. For much lower size factors, the scattering cross section is Thanks for contributing an answer to Physics Stack Exchange! A linear array, or line of antennas, will permit azimuth (side to side) steering of the antenna. In this case, steering of the receive direction is more straightforward, due to the digital processing of the receive signal.

Beamwidth, or the ability of the radar to focus the radiated and received energy in a narrow region, is also dependent on both The range of the radar system is also influenced by the choice of frequency. Aside from this, you need to choose a frequency which will propagate well in the atmosphere without absorption, and a frequency at which you can readily generate powerful signals at. This is an issue only with a particular type of system; the Consider the positive shift caused by the closing target in the diagram which has been highly simplified for clarity. A radar with a 1° horizontal beamwidth that sweeps the entire 360° horizon every 2 seconds with a PRF of 1080 Hz will radiate 6 pulses over each 1-degree arc.

c = Speed of Light (299,792,458 m/s) f = Frequency. Airborne applications often are limited in the size of antenna that can be used, which will dictate a higher frequency and lower wavelength choice.