The Doppler radar

The Doppler radar

Introduction

Before introducing the Doppler radar, initially we must review some concepts relating to it. Doppler shift is a shift in frequency that happens due to the movement of scatterers towards or away from the observer in the electromagnetic waves. Its example can easily be understood by the shift of sound waves frequency in car racing from the perspective of a stationary spectator. Doppler radar is the type of radar that analyzes the shift in frequency measurement and the phase change that happens in electromagnetic waves throughout the pulse series. Radar mainly consists of a transmitter, antenna & receiver. It can be used as a combination with the additional circuitry to perform more versatile and additional tasks. It also has the dedicated signal processors that are equipped with estimators for reflectivity, spectrum and velocity width i.e. ground clutter cancellers and data formatting, checking the quality and processors regarding radar control. The data display and its analysis are helped by metrological processors, associated color displays, product generator and communication ports.

Discussion

WSR-88d is the 2nd generation radar with operational meteorological advancements. It has replaced non meteorological radars of Air force and weather services. It is advanced version of the previous one in engineering design as well as meteorological measurements. It is fully coherent, and provides accurate measurements, spatial location, distribution as well as the radial component of motion of scatterers and dispersion of velocities in sample radar volume (spectrum width). Data flow rate of WSR-88D is larger and that is the reason why high speed data processing is desired in order to have an effective and efficient human-machine interface.

The Doppler weather radar and its signals are examined from elementary considerations to show the origin and development of useful weather echo properties such as signal-to-noise ratio (SNR), range correlation, signal statistics, etc.

Description of Doppler radar

RADAR (radio detection and ranging - i.e. detection and distance measurement by radio) is the Perhaps the most important application of radio frequency technology in addition to telecommunications. Many technical aspects of radar technology differ little from those of Telecommunications. You need transmitters, receivers and antennas, as does the modulation of the used Si signals play a role, so too the extraordinary importance of the analogue and in ever greater Mass, digital signal processing is obvious. An important difference to television and RF applications, however, is the fact that the overwhelming number of radars is monostatic, ie transmitter and receiver-being at the same place and usually uses the same antenna. With the exception of secondary radar systems in which the target (object to be detected), a transponder (i.e. an active electronics are) must radars be able to own the transmission signal received gene, i.e. the (almost) same frequency and this is (almost) simultaneously.

This brings a number of problems that are of the Telecommunications her little known and demand for specific solutions. Against this background it is understandable that un- different requirements in terms of reach, distance and angular resolution, type of require targets, ...