scholarly journals IR-Band Conversion of Target and Background Using Surface Temperature Estimation and Error Compensation for Military IR Sensor Simulation

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2455 ◽  
Author(s):  
Taewuk Bae ◽  
Youngchoon Kim ◽  
Sangho Ahn

Military infrared (IR) imaging systems utilize one or more IR wavelength-bands, among short wavelength IR (SWIR), middle wavelength IR (MWIR), and long wavelength IR (LWIR) band. The IR image wavelength-band conversion which transforms one arbitrary IR wavelength-band image to another IR wavelength-band image is needed for IR signature modeling and image synthesis in the IR systems. However, the IR wavelength-band conversion is very challenging because absorptivity and transmittance of objects and background (atmosphere) are different according to the IR wavelength band and because radiation and reflectance characteristics of the SWIR are very different from the LWIR and MWIR. Therefore, the IR wavelength-band conversion in this paper applies to only IR targets and monotonous backgrounds at a long distance for military purposes. This paper proposes an IR wavelength-band conversion method which transforms one arbitrary IR wavelength-band image to another IR wavelength-band image by using the surface temperature estimation of an object and the error attenuation method for the estimated temperature. The surface temperature of the object is estimated by an approximated Planck’s radiation equation and the error of estimated temperature is corrected by using the slope information of exact radiance along with the approximated one. The corrected surface temperature is used for generating another IR wavelength-band image. The verification of the proposed method is demonstrated through the simulations using actual IR images obtained by thermal equipment.

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Tae Wuk Bae ◽  
Young Choon Kim ◽  
Sang Ho Ahn

Infrared (IR) target signatures and background scenes are mainly used for military research purposes such as reconnaissance and detection of enemy targets in modern IR imaging systems like IR search and track (IRST) system. For understanding and analyzing IR signatures and backgrounds in the IR imaging systems, an IR wavelength band (WB) conversion which transforms an arbitrary WB image to another WB is very important in the absence of equipment by WB. In addition, IR image synthesis of targets and backgrounds can provide a great deal of information in the IR target detection field. However, the WB conversion is actually a very challenging research due to lack of information on the absorptivity and transmittance of enormous components of an object or atmosphere. In addition, the radiation and reflectance characteristics of short-wave IR (SWIR)-WB are very different from those of long-wave IR (LWIR)-WB and middle-wave IR (MWIR)-WB. Therefore, the WB conversion in this paper is limited only to IR target signatures and monotonous backgrounds, which is commonly used for military purposes, at a long distance. This paper proposes an IR synthesis method for generating a synthesized IR image of three IR-WBs by synthesizing an IR target signature and a real background scene for an arbitrary IR-WB. In the proposed method, each temperature information is first estimated from an IR target signature and IR background image for an arbitrary IR-WB, and then a synthesized temperature image is generated by combining the respective temperature information estimated from the IR target signature and background scene. Finally, the synthesized temperature image is transformed into an IR radiance image of three IR-WBs. Through the proposed method, various IR synthesis experiments are performed for various IR target signature and background scenes.


2013 ◽  
Vol 6 (6) ◽  
pp. 151-162
Author(s):  
Bong-Seob Kim ◽  
Hyuk-Ju Kwon ◽  
Tae-Wuk Bae ◽  
Sang-Ho Ahn ◽  
Young-Choon Kim ◽  
...  

2021 ◽  
Author(s):  
Aravind Chandh ◽  
Oleksandr Bibik ◽  
Subodh Adhikari ◽  
David Wu ◽  
Tim Lieuwen ◽  
...  

Abstract In this paper, we discuss the development of a non-intrusive surface temperature sensor based on long-wavelength infrared (LWIR) hyperspectral technology. The LWIR detection enables to minimize optical interferences from hot combustion gases (emission mostly within UV-MWIR region). Utilization of hyperspectral detection allows to further improve temperature measurement accuracy and precision. The developed sensor with fiber coupling provides the required flexibility to be maneuvered around/through combustor hardware. The LWIR fiber probe is fully protected by the custom-designed water-cooled probe housing. This device is designed to sustain temperature of 2400 K at pressure of 50 bar, which enables long-term optical diagnostics inside the practical high-pressure combustion facilities where extreme thermal acoustic perturbation and intense heat fluxes are present. The housing featured a diamond window to selectively measure spectra in the LWIR region to get accurate surface temperature exclusively of the combustor wall. The probe was installed into a RQL style combustor to get surface temperature of both hot and cold side of the combustor wall. Further, pointwise heat flux estimates across the combustion liner wall was derived using the temperature measurements.


Author(s):  
Yuri P. Perevedentsev ◽  
Konstantin M. Shantalinskii ◽  
Boris G. Sherstukov ◽  
Alexander A. Nikolaev

Long-term changes in air temperature on the territory of the Republic of Tatarstan in the 20th–21st centuries are considered. The periods of unambiguous changes in the surface air temperature are determined. It is established that the average winter temperature from the 1970s to 2017, increased in the Kazan region by more than 3 °C and the average summer temperature increased by about 2 °C over the same period. The contribution of global scale processes to the variability of the temperature of the Kazan region is shown: it was 37 % in winter, 23 % in summer. The correlation analysis of the anomalies of average annual air temperature in Kazan and the series of air temperature anomalies in each node over the continents, as well as the ocean surface temperature in each coordinate node on Earth for 1880 –2017, was performed. Long-distance communications were detected in the temperature field between Kazan and remote regions of the Earth. It is noted that long-period climate fluctuations in Kazan occur synchronously with fluctuations in the high latitudes of Asia and North America, with fluctuations in ocean surface temperature in the Arctic ocean, with fluctuations in air temperature in the Far East, and with fluctuations in ocean surface temperature in the Southern hemisphere in the Indian and Pacific oceans, as well as air temperature in southern Australia. It is suggested that there is a global mechanism that regulates long-term climate fluctuations throughout the Earth in the considered interval of 200 years of observations. According to the CMIP5 project, climatic scenarios were built for Kazan until the end of the 21st century.


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