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In this paper the author has suggested the use of P-R sequences, to generate random phase characteristics of the currents fed to a phased-array antenna, together with a suitable (r, , ) gating system. A radar system built on this technique could also incorporate a correlator, without any difficulty, for better detectability of signals accompanied by noise. Key-words: P-R sequences, phased-array antenna, correlator, phase-modulation, range-gating. [ABSTRACT FROM AUTHOR]

There are two important problems that arise in the use of amplitrons, as broadband microwave amplifiers in high power radar systems with frequency agility.
The first one is to modify the conventional high vacuum tube modulator to obtain proper operation with good efficiency in case of very high power levels.
The second one is to modify the modulator circuit by increasing its output impedance and thus limiting the peak current variations in the transmitted frequency band.
In this paper analyses are made of both these Problems, some practical results are given, and the implication in actual transmitter design is examined. [ABSTRACT FROM AUTHOR]

Examination of representative and recently declassified samples of imagery from the type of radar developed especially for reconnaissance and mapping purposes by the military, the Side-Looking Airborne Radar ("SLAB"), indicates that SLAB images look very much like medium-grade aerial photos and will serve the following types of geographic tasks even better. 1) Tasks which require an overview of subcontinental magnitude. 2) Tasks which require an overview in which careful timing is critical. 3) Tasks which require an overview with maximum economy of time and money.

The article provides information on a study concerning the weather radar measurement of bird migration. It is known that radar becomes an important tool for the studies of bird migration. However, it is difficult to estimate bird densities from echo densities on the radar screen. The use of the Weather Bureau's new WSR-57 radar for bird migration research is also discussed. The shorter pulse of this radar has greater resolution but only detects birds when they are highly concentrated in the air. The fading of pulse radar signals reduces the number of perceptible returns because of the distribution of the numbers of targets among the radar.

The article presents information on the two Nobel Prize winners Edward Appleton and Robert Robinson in the United States. Both men are from the North country from which they have drawn various characteristics. Appleton works in elucidating how wireless waves travel made long distance radio communication the precision method for up-to-the minute international contact and led to the development of radar. Appleton is head of the Government organization which is responsible for the applications of science to national needs. Appleton's work has been noticed mainly in the United States where the signal honor of the Medal of Merit was given him for his early work on radar and for his services. Robinson has always held academical appointments, being Professor in Sydney, Australia and several British Universities. Robinson discovered a simple synthesis for tropinone, a substance that can be obtained from and converted into the plant alkaloids atropine and cocaine.