Mr. Jaroslav Krejcí Profile

Jaroslav Krejcí

at Univ of Defence

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Publications (7)

Proceedings Article | 17 October 2019 Presentation + Paper

Evaluation of target acquisition performance in photosimulation test

František Racek, Teodor Baláž, Jaroslav Krejčí

Proceedings Volume 11158, 111580N (2019) https://doi.org/10.1117/12.2532807

KEYWORDS: Camouflage, Target acquisition, Statistical analysis, Surveillance, Standards development, Imaging devices, Image processing, Target detection, Photography, Image resolution

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Proceedings Article | 7 October 2019 Presentation + Paper

Modelling of UAV range measurement

Teodor Balaz, Jaroslav Krejci, Frantisek Racek

Proceedings Volume 11166, 111660F (2019) https://doi.org/10.1117/12.2533043

KEYWORDS: Unmanned aerial vehicles, Distance measurement, Weapons, Reflectivity, Target detection, Statistical analysis, Medium wave, Modeling, Optoelectronics, Image processing

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Nowadays, there is wide spectrum of areas of use of small unmanned aerial vehicles (UAV, drones). Their low cost, flexibility of use, low service cost and independence on infrastructure make them ideal carriers of different cargo. This fact brings many significant safety risk and threats. Especially aerial survey, flight zones disruptions and transport dangerous cargo. Above mentioned threat can be eliminated by: disabling navigation and control features, taking control over the steering and object destruction. One of the possible typically military solutions of that situation, is destruction by shooting. The most common way of solving the above task, is the use of barrel weapons of individual shooter or small military units. Therefore, we focused our effort on preventing the UAV mission accomplishing by its shooting destruction. To accomplish the task, in addition to detection and identification, we consider the distance determination as a fundamental problem. For the purposes of this paper, the distance determination we consider as a “localization”. Comparison of UAV localization options is the issue of this paper. Two localizations methods have been defined. Localization option include active method (ILR – impulse laser rangefinder) and passive method (triangulation method). Using mathematical modelling we proved, that ILR measurement is possible. To determine a distance with a defined probability we designed specific measurement frequency. For a predetermined type of UAV and ILR we identified the maximum distance that can be measured. In the second part of this paper, we analyzed the accuracy of localization using the triangulation method. The accuracy of localization using this method is dependent on the squared of the UAV distance. There are two significant advantage of this method: measurements can be made continuously and multiple objects in the field of view can be measured at the same time. This article is part of a planned publishing activity dealing with the issue

Proceedings Article | 9 October 2018 Presentation + Paper

NATO hyperspectral measurement of natural background

V. Bárta, F. Racek, J. Krejcí

Proceedings Volume 10794, 1079405 (2018) https://doi.org/10.1117/12.2325468

KEYWORDS: Reflectivity, Sensors, Short wave infrared radiation, Cameras, Signal to noise ratio, Calibration, Time metrology, High dynamic range imaging, Fabry–Perot interferometers, Data processing

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Proceedings Article | 9 October 2018 Presentation + Paper

Evaluation of validity of observer test for testing of camouflage patterns

František Racek, Adam Jobánek, Teodor Baláž, Jaroslav Krejčí

Proceedings Volume 10794, 107940E (2018) https://doi.org/10.1117/12.2325101

KEYWORDS: Camouflage, Visualization, Reliability, Defense and security, Target detection, Statistical analysis, Analytical research

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Proceedings Article | 5 October 2017 Paper

Selected issues connected with determination of requirements of spectral properties of camouflage patterns

František Racek, Adam Jobánek, Teodor Baláž, Jaroslav Krejčí

Proceedings Volume 10432, 1043205 (2017) https://doi.org/10.1117/12.2277906

KEYWORDS: Camouflage, Reflectivity, Tolerancing, Colorimetry, Manufacturing, Camouflage concealment and deception, Control systems, Safety, Defense and security

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Proceedings Article | 5 October 2017 Presentation + Paper

Tracking, aiming, and hitting the UAV with ordinary assault rifle

František Racek, Teodor Baláž, Jaroslav Krejčí, Stanislav Procházka, Martin Macko

Proceedings Volume 10441, 104410C (2017) https://doi.org/10.1117/12.2276310

KEYWORDS: Unmanned aerial vehicles, Firearms, Target detection, Visualization, Optical tracking, Reconnaissance, Weapons, Space telescopes, Telescopes, Probability theory

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Proceedings Article | 24 October 2016 Presentation + Paper

Pixelated camouflage patterns from the perspective of hyperspectral imaging

František Racek, Adam Jobánek, Teodor Baláž, Jaroslav Krejčí

Proceedings Volume 9997, 99970G (2016) https://doi.org/10.1117/12.2240915

KEYWORDS: Camouflage, Spatial frequencies, Cameras, Imaging systems, Hyperspectral imaging, Image processing, Point spread functions, Reflectivity, Optical transfer functions, Fourier transforms

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Showing 5 of 7 publications

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