Radar

Similar Terms: FMCW, fmcw, Frequency Modulated Continuous Wave Radar, Broadband

RADAR is an acronym for Radio Detection And Ranging, coined by the U.S. Navy in 1940. It is the use of electromagnetic waves - specifically radio waves - to determine the Range, altitude, direction, or speed of both moving and fixed objects.

The radar broadcasts a specific, or Range of frequencies and detects the returning wave of the same Frequency, bounced off an object. Using digital signal processing these returning radio waves are used to Plot distance, direction and speed of the object that caused the returning signal.

Since most radio waves are able to pass through fog, clouds, rain, falling snow, and sleet, RADAR is used in marine and aeronautical settings over and above infared or UV light methods for distance object detection in a marine radar.

Broadband Radar

Lowrance's and Simrad's designation of the FMCW (Frequency Modulated Continious Wave) Radar technology.

The word “broadband” nowadays is associated with good computer connectivity; Lowrance and Simrad justified the use of this term because its Radar emits signals along a broad Range of frequencies. It does this without a magnetron, instead using two solid-state amplifiers: one to transmit waves at continuously increasing frequencies, the other to simultaneously receive their echoes.

FMCW Transmitter as the name suggests, sends a signal where the Frequency is continually changed in a repeatable pattern (modulated) over time. By varying the Frequency in this manner, you can gather both Range and velocity information with significantly improved Azimuth Resolution over greater Range and particularly for close proximity targets.

The main hardware difference between the two Radar types is that pulse radars use magnetrons to generate the energy that they radiate whilst FMCW radars use solid state amplifiers. Another is that in the leisure-marine market pulse radars use a single Antenna, whilst an FMCW one uses two - one mounted on top of the other, generally in the same enclosure.

The difference arises because pulse radars either transmit or receive: FMCW ones do both at the same time and untilise significant digital processing capability to display the target. The difference in transmission also means that no harmful radiation is emitted outside the dome, allowing for flexible installation on a Range of vessels.