Evaluation of the thermal contrast of low-temperature ground-based objects

Publication in Journal of Optical Technology

For Russian citation (Opticheskii Zhurnal):

Овсянников В.А., Овсянников Я.В. Оценка теплового контраста низкотемпе-ратурных наземных объектов // Оптический журнал. 2022. Т. 89. № 10. С. 5–12. http://doi.org/10.17586/1023-5086-2022-89-10-05-12

Ovsyannikov V.A., Ovsyannikov Ya.V. Evaluation of the thermal contrast of low-temperature ground-based objects [in Russian] // Opticheskii Zhurnal. 2022. V. 89. № 10. P. 5–12. http://doi.org/10.17586/1023-5086-2022-89-10-05-12

For citation (Journal of Optical Technology):

V. A. Ovsyannikov and Ya. V. Ovsyannikov, "Evaluation of the thermal contrast of low-temperature ground-based objects," Journal of Optical Technology. 89(10), 563-568 (2022). https://doi.org/10.1364/JOT.89.000563

Abstract:

Subject of study. The thermal contrast of low-temperature passive terrain objects is the difference in radiant temperatures of an object and background in operating spectral regions of air- and ground-based thermal imaging devices for surveillance. Aim of study. The study attempted to provide the designers of thermal imaging devices with initial data for signature features of ground-based objects. Method. The study employed a theoretical analysis on the physical dependences of the formation of thermal contrast in ground-based objects using the previously published model of thermal radiation of the atmosphere, which, in addition to temperature contrast owing to the different thermal inertias of the object and background upon alterations in meteorological conditions, considers the optical properties of the object, solar and environmental (of the Earth’s surface and atmosphere) radiation reflected from the object, and viewing direction of three-dimensional objects. Main results. A methodological approach and corresponding mathematical model were proposed for the quick engineering evaluation of the main signature feature of low-temperature ground-based objects, particularly vehicles surveilled using thermal imaging devices from the upper hemisphere against the background of the Earth’s surface at different cloud coverage, i.e., their thermal contrast in the spectral regions of 3–5 and 8–12 µm corresponding to the atmospheric windows. Accordingly, we presented the analytical expressions for this evaluation considering environmental thermal radiation, direct and scattered solar radiation reflected by the diffuse spherical surface imitating the surveilled object, and its viewing direction. The possibility of thermal contrast variation in the rather wide range and its inversion was demonstrated even for a fixed temperature contrast. An example of a practical application of the proposed model was considered. Practical significance. The developed engineering method for calculating the thermal contrast of ground-based objects can be applied to quickly estimate effectiveness, including the operating range of air- and ground-based thermal imaging devices, and validate the requirements on the main technical parameters of prospective devices of this type.

Keywords:

thermal contrast, low-temperature ground objects

OCIS codes: 010.7295, 110.6820

References:

1. P. A. Jacobs, Thermal Infrared Characterization of Ground Targets and Background (SPIE Press, Bellingham, Washington, 2006).
2. V. P. Ivanov, V. I. Kurt, V. A. Ovsyannikov, and V. L. Fillipov, Modeling and Evaluation of Modern Thermal Imaging Devices (Otechestvo, Kazan, 2006).
3. B. V. Skvortsov, A. S. Pertsovich, and D. M. Zhivonosnovskaya, “Simulation modeling of the signature of a thermal object,” J. Opt. Technol. 85(4), 211–217 (2018) [Opt. Zh. 85(4), 28–35 (2018)].
4. B. Wang, Y. Xie, Y. Yuan, and W. Zhang, “Calculation of temperature variation and infrared detection probability of the desert ground target,” Proc. SPIE 10255, 102554Z (2017).
5. C. Plesa, D. Turcanu, and V. Bodoc, “The use of infrared radiation for thermal signatures determination of ground targets,” Rom. J. Phys. 51(1–2), 63–72 (2006).
6. V. L. Filippov and I. G. Venderevskaya, “Model calculation of the spectral transmittance and radiance of the atmosphere as they vary with weather conditions: development results,” J. Opt. Technol. 84(3), 167–172 (2017) [Opt. Zh. 84(3), 15–21 (2017)].
7. A. V. Markov and V. N. Ostrikov, “Computational thermodynamics modeling of infrared images of terrestrial objects,” J. Opt. Technol. 67(7), 687–692 (2000) [Opt. Zh. 67(7), 100–105 (2000)].
8. J. Sanders, K. Johnson, A. Curran, and P. Rynes, “Ground target infrared signature modeling with the multiservice electro-optic signature code,” Proc. SPIE 4029, 197–204 (2000).
9. P. Clare, “Design and modeling of spectral-thermal unmixing targets for airborne hyperspectral imagery,” Proc. SPIE 6233, 62331J (2006).
10. Y. Ata and K. Nakiboglu, “Infrared signature estimation of an object or a target by taking into account atmospheric effects,” Opt. Commun. 283, 3901–3910 (2010).
11. L. T. Matveev, General Metrology Course: Atmospheric Physics (Gidrometeoizdat, Leningrad, 1984).

12. V. A. Ovsyannikov and Ya. V. Ovsyannikov, “Estimating the contrast radiant intensity of aerial objects for ground-based television equipment,” Aviakosm. Priborostr. (2), 3–12 (2022).
13. V. A. Ovsyannikov and Ya. V. Ovsyannikov, “Threshold sensitivity of staring thermal imaging devices operating in slant atmospheric paths,” J. Opt. Technol. 89(10), 569–577 (2022) [Opt. Zh. 89(10), 13–25 (2022)].
14. V. P. Vavilov, Infrared Thermography and Thermal Control (Spektr, Moscow, 2009).
15. A. F. Belozerov and V. M. Ivanov, Foreign Thermal Imaging Devices (NTTs Informtekhnika, Moscow, 2004).
16. V. A. Ovsyannikov and Ya. V. Ovsyannikov, “Rational selection of the operating spectral range for modern thermal imaging devices,” Kontenant 18(4), 68–86 (2019).