DEVICE FOR SUBTRACTION OF BACKGROUND (NOISE) (USTROISTVO AVTOMATICHESKOGO VYCHITANIYA FONA),
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 09, 1967
- Accession Number
- AD0675271
Entities
People
- A. V. Dmitriev
- N. D. Balyasnyi
- V. A. Ionov
Organizations
- National Air and Space Intelligence Center