Method of determining the signal level at the input of the optical receiver of surveillance equipment

Andrey Sadchenko; Oleg Kushnirenko; Alexander Troyanskiy

doi:10.15222/TKEA2020.1-2.15

Andrey Sadchenko Odessa National Polytechnic University https://orcid.org/0000-0002-2517-6892
Oleg Kushnirenko Odessa National Polytechnic University https://orcid.org/0000-0002-7045-5620
Alexander Troyanskiy Odessa National Polytechnic University https://orcid.org/0000-0001-9755-6010

DOI: https://doi.org/10.15222/TKEA2020.1-2.15

Keywords: acousto-optic leakage channel, signal level, calculation method, minimum detected power

Abstract

The paper considers typical designs of surveillance devices for acousto-optic leakage channels. To assess the quality of the channel, it is proposed to use the criterion of the minimum permissible power of the information signal at the input.
To analyze the processes that occur while the probe signal propagates to the pick-up point and back to the surveillance device, the authors propose a detailed model of the information leakage channel with the indication of the main transformations of the intercepted signal. The paper presents the main criteria for the correct reception of an optical signal and for the extraction of acoustic information from it. A number of assumptions are formulated regarding the practical implementation of the optoelectric converter of the receiving device, and a simplified equivalent functional model of the optical information transmission channel is developed.
The authors also propose a method for calculating the voltage at the load of the photodiode depending on the distance to the vibrating surface, power and the coefficient of directional action of the transmitter emitter. The numerical dependences of the voltage at the load of the photodiode on the distance are obtained for specific numerical values of the load resistance, supply voltage, directional coefficient of the emitter and receiver, as well as the geometric dimensions of the information interception zone. A simplified technique is developed that allows determining the signal level at the input of the sensitive element of a photodetector under idealized conditions, if the minimum permissible optical signal power condition is met and there is no background illumination of the photodetector of the surveillance device.

References

Katorin Yu. F., Kurenkov Ye. V., Lysov A. V., Ostapenko A. N. Bol'shaya entsiklopediya promyshlennogo shpionazha [Great encyclopedia of industrial espionage], Russia, St. Petersburg, Ltd “Poligon”, 2000, 896 p. (Rus) https://doi.org/10.3390/s18041156

Li X., Yang B., Xie X., Li D., Xu L. Influence of waveform characteristics on LiDAR ranging accuracy and precision. Sensors, 2018, vol. 18, iss. 4, pp. 1156. https://doi.org/10.3390/s18041156

Li X., Wang H., Yang B., Huyan J., Xu L. Influence of time-pickoff circuit parameters on LiDAR range precision. Sensors. 2017, vol. 17, iss. 10, pp. 2369. https://doi.org/10.3390/s17102369

Khorev A.A. [Means of the acoustic reconnaissance: directional microphones and the laser acoustic systems of reconnaissance]. Spetstekhnika i svyaz', Moskow, 2008, no. 2, pp. 24–29. (Rus)

Abrakitov V.E. Bagatorazovi vidbyttya zvuku v akustychnykh rozrakhunkakh [Multiple sound reflections in acoustic calculations]. Ukraine, Kharkiv National Academy of Municipal Economy, 2007, 416 p. (Ukr)

Katorin Yu.F. [Estimation of the possibilities of directional microphones with theinterception of sound signals]. Vestnik policii, 2015, vol. 3, iss. 1, pp. 28–33. https://doi.org/10.13187/VesP.2015.3.28 (Rus)

Didkovskiy V. S., Didkovskaya M. V., Prodeus A. N. Akusticheskaya ekspertiza kanalov rechevoy kommunikatsii [Acoustic speech communication channel expertise]. Kyiv, Imeks-LTD, 2008. 420 p. (Rus)

Sokolov, A. I., Monakhov M. Yu. Tekhnicheskiye sredstva zashchity informatsii: tekhnicheskiye kanaly utechki informatsii [Technical means of information protection: technical channels for information leakage]. Russia, Publishing House of Vladimir State University, 2006, 71 p. (Rus)

Zolotareva K.N. [Laser microphone as technical equipment for reconnaissance] Proceedings of the III Conference “IT: Yesterday, today, tomorrow”, St. Petersburg, Admiral Makarov State University of Maritime and Inland Shipping , 2015, pp. 168–169 (Rus)

Glushhenko A.V., Glushhenko L.A., Tupota V.I. Matematicheskaya model’ polucheniya informatsii ob akusticheskom rechevom signale po otrazhennomu lazernomu izlucheniyu.” Proceedings of the 20-th Int. Conf. “Lasers Measurements. Information 2010», vol. 1, St. Petersburg, Politechnical University, 2010, pp. 209–220 (Rus)

Qiu, Q., Lau, D. The Sensitivity of Acoustic-Laser Technique for Detecting the Defects in CFRP-Bonded Concrete Systems. Journal of Nondestructive Evaluation, 2016, vol. 35, art. no. 33. https://doi.org/10.1007/s10921-016-0351-y

Ezhgurov V.N., Katorin Yu.F., Nyrkov A.P., Sokolov S.S. [The basic principles of building secure information systems for automated management of the transport-logical complex] Information Security Problems. Computer Systems, 2013, no. 2, pp. 54–58. (Rus)

Glushhenko A. V., Glushhenko L. A., Korzun A. M., Tupota V. I. [Otsenka effektivnosti polucheniya informatsii ob akusticheskom signale po otrazhennomu lazernomu izlucheniyu]. Proc. of the IX Int. Conf. “Prikladnaja Optika-2010”, St. Petersburg, 2010, pp. 71–75. (Rus)

Grishachev V. V., Haljapin D. B., Shevchenko N. A., Merzlikin V. G. [New channels for leakage of confidential voice information through fiber optic subsystems SCS]. Specialnaja tehnika, 2009, no. 2, pp. 2–9. (Rus)

Katorin Ju. F., Korotkov V. V., Nyrkov A. P. [Information security in the channels of data transmission on the waterside networks of automatic identification system]. Journal of Admiral Makarov State University of Maritime and Inland Shipping, St. Petersburg, 2012, no. 1, pp. 98–102. (Rus)