Accession Number : AD0675271

Title :   DEVICE FOR SUBTRACTION OF BACKGROUND (NOISE) (USTROISTVO AVTOMATICHESKOGO VYCHITANIYA FONA),

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Balyasnyi,N. D. ; Dmitriev,A. V. ; Ionov,V. A.

Report Date : 09 NOV 1967

Pagination or Media Count : 12

Abstract : In automating the processing of air-gamma-survey materials (intensity-flight-altitude calculations, channel rate-of-counting division, etc.), a special device must be used for presubtracting the background components during the flight. A device is described which automatically substracts the background rate-of-counting in the pulse form. The advantage of this method of isolating the desirable signal lies in the fact that the background is subtracted right at the radiometer input; the automatic-stabilization circuit in the air-survey system is simplified, the background compensation with sensitivity-scale switching becomes unnecessary, and the possibility of count recording in the pulse form with an accuracy of one pulse is retained. The equipment includes a two-position subtracting unit, an electronic delay circuit, a logical unit, and a memory unit. The subtracting-unit error is investigated for the particular case when the pulse sequence is set by a separate background frequency-stabilized generator, and the input pulses are statistically distributed according to the Poisson law. If the subtracting unit switch has more than two positions, missing of a pulse of the background generator will depend not only on the number of the arrived input pulses but also on the switch position at the start of the period; therefore, in this case, the operation would be described by a Markov-type-circuit probabilistic process. A table and a recurrent formula set up for various sequences of the input pulses are analyzed. (Author)

Descriptors :   (*GAMMA COUNTERS, USSR), RADIOMETERS, MEASUREMENT, BACKGROUND, DELAY CIRCUITS, ACOUSTIC PROPERTIES, SENSITIVITY, AUTOMATIC, STABILITY, PULSES, INTENSITY, AIRBORNE

Subject Categories : Test Facilities, Equipment and Methods
      Nuclear Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE