Accession Number : AD0682775

Title :   DECREASING THE EFFECT OF 'BLIND ALTITUDES' IN RADAR PATH VELOCITY MEASUREMENT DEVICES,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Tenin,M. B.

Report Date : 08 MAR 1968

Pagination or Media Count : 14

Abstract : The technique of wobbulating the pulse repetition rate to eliminate the undesirable effect of 'blind heights' is analyzed as it applies to pulsed Doppler radars which are used to determine ground speed and which incorporate high pulse repetition rates and a low ratio of pulse interval to pulse width. An analysis has been carried out to determine the variation in the fundamental frequency of the received signal as a function of its delay time when a small percentage of wobbulation is used. For the sake of simplicity, the analysis uses the video frequency and assumes that the variations in the intensity of the received signal are similar to the variations in the dc component of the envelope for the video pulses. It is shown that the effect of 'blind heights' can be substantially reduced and the basic frequency in the spectrum of the output signal can be made constant. Optimum values for the percentage wobbulation are derived for the case of a harmonic law and a non-symmetric saw-tooth law. The use of the non-symmetric saw-tooth law for wobbulation is recommended for practical purposes.

Descriptors :   (*DOPPLER RADAR, PERFORMANCE(ENGINEERING)), RADAR SIGNALS, PERIODIC VARIATIONS, VELOCITY, ALTITUDE, OPTIMIZATION, USSR

Subject Categories : Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE