lobe switching

Lobe switching is a method used on early radar sets to improve tracking accuracy.

Lobe switching offered greatly improved accuracy for the addition of a small amount of complexity.

Lobe switching was incorporated in the transmitting array, giving high directional accuracy.

It had a very complex set of three antennas on a horizontal, rotatable boom and used lobe switching.

This enabled the system in effect to switch from the rather broad "scanning for maxima" to narrow lobe switching.

Even with the relatively long wavelengths used, accuracies on the order of a degree could be attained with these lobe switching systems.

It is possible to jam a lobe switching radar with relative ease if one knows the basic operating frequencies of the radar.

Major James C. Moore was assigned to head the complex electrical and mechanical design of lobe switching antennas.

Each pair of antennas was connected to a motorized switch that rapidly switched between the pairs, a technique known as lobe switching.

Reception from both, using lobe switching, was sent to the left and right sides of a vertically oriented A-scope, and range could be measured as before.

With 25-kW output and a pair of Yagi antennas incorporating lobe switching, it was trialed in June 1939.

Conical scanning was similar in concept to lobe switching, but as the name implies it was operated in a rotary fashion instead of two directions.

This lobe switching concept was used in the so-called Flimmerschalter in the German Lichtenstein radar during World War II.

The wide-band regenerative receiver used Acorn tubes from RCA, and the receiving antenna had three pairs of dipoles and incorporated lobe switching.

Secondary Scan: A scanning technique where the antenna feed is moved to produce a scanning beam, examples include conical scan, unidirectional sector scan, lobe switching, etc.

The SCR-268 was one of the first radar sets to use lobe switching of its receiving antennas as a means to locate AA (anti-aircraft) searchlight beams on aircraft.

The transmitting antenna was an array of 10 pairs of dipoles with a reflecting mesh, and the receiving antenna had three pairs of dipoles and incorporated lobe switching.

The system performance was excellent; the range was read off the Braun tube with a tolerance of 50 meters (less than 1 percent variance), and the lobe switching allowed a directional accuracy of 0.1 degree.

This metric wavelength system employed six yagi antennas that could take ranges of targets, and take accurate readings of bearing using a technique known as "lobe switching" but only crude estimates of altitude.

Early units were technically behind the times in terms of tracking in particular; while the SCR-268 was being introduced, the Germans were upgrading the Würzburg radar, first to use lobe switching, and finally to conical scan the next year.

To do this, one adds a second antenna with the rotating lobe for reception only, a system known as COSRO, for Conical Scan on Receive Only (compare to LORO, a similar system used against lobe switching radars).

Conical scanning is similar in concept to the earlier lobe switching concept used on some of the earliest radars, and many examples of lobe switching sets were modified in the field to conical scanning during World War II, notably the German Würzburg radar.