KEYWORDS: Satellite navigation systems, Receivers, Control systems, Near infrared, RGB color model, Video, Navigation systems, Image segmentation, Antennas, Chemical elements
This paper describes preliminary results of the interdisciplinary research and development venture lead by The Military University of Technology, Warsaw, Poland. The main task of the project is to develop remote solutions that support dogs guide during different special activities. According to the law-enforcement operational procedures, system has been designed basing on three different modules: special dogs electronic vest, mobile command center and supporting UAV (Unnamed Airborne Vehicle) platform. Project integrates such technologies as GNSS (Global Navigation Satellite System), IMU (Inertial Measurement Unit), remote sensing tools and UAV platforms as a support device. General idea of the project comes from boarder control and law-enforcement forces whose big scope of work is related with K-9 dogs activity. The main functionality of the system is to monitor and control the K-9 dog during high level risk operations. The biggest challenge of the project is to develop official training and operational procedures suitable to the applied technology.
This article presents general concept of the system and the results of validation process in scope of remote sensing (NIR , RGB) and navigation functionalities (GNSS). The set of tests has been taken with different methods and tools to establish efficient ergonomic solution. Possibilities of project application areas are also shown here in details.
The paper describes the results of experimental research on the mobile verification of travellers based on fingerprints. Three-day tests were carried out at the border crossing in Terespol, Poland. The developed system automatically acquires personal and biometric data (fingerprints) from the Polish biometric passport, determines their quality and compares with the live data collected from the traveller. In addition, the system measures the time of individual stages of the process and determines total transaction time. For total number of correctly scanned travellers equal to 128, false acceptance rate equals to 0, while rejection rate is less than 1%. The average transition time of border check was 37 seconds.
KEYWORDS: Cameras, Target detection, Signal to noise ratio, Minimum resolvable temperature difference, Image quality, 3D modeling, Target recognition, Interference (communication), Imaging systems, Temperature metrology
During the design of a system employing thermal cameras one always faces a problem of choosing the camera types best suited for the task. In many cases such a choice is far from optimal one, and there are several reasons for that. System designers often favor tried and tested solution they are used to. They do not follow the latest developments in the field of infrared technology and sometimes their choices are based on prejudice and not on facts. The paper presents the results of measurements of basic parameters of MWIR and LWIR thermal cameras, carried out in a specialized testing laboratory. The measured parameters are decisive in terms of image quality generated by thermal cameras. All measurements were conducted according to current procedures and standards. However the camera settings were not optimized for a specific test conditions or parameter measurements. Instead the real settings used in normal camera operations were applied to obtain realistic camera performance figures. For example there were significant differences between measured values of noise parameters and catalogue data provided by manufacturers, due to the application of edge detection filters to increase detection and recognition ranges. The purpose of this paper is to provide help in choosing the optimal thermal camera for particular application, answering the question whether to opt for cheaper microbolometer device or apply slightly better (in terms of specifications) yet more expensive cooled unit. Measurements and analysis were performed by qualified personnel with several dozen years of experience in both designing and testing of thermal camera systems with both cooled and uncooled focal plane arrays. Cameras of similar array sizes and optics were compared, and for each tested group the best performing devices were selected.
KEYWORDS: Cameras, Thermography, Manufacturing, Sensors, Minimum resolvable temperature difference, Modulation transfer functions, 3D modeling, Target detection, Target recognition, Imaging systems
Measured range characteristics may vary considerably (up to several dozen percent) between different samples of the same camera type. The question is whether the manufacturing process somehow lacks repeatability or the commonly used measurement procedures themselves need improvement. The presented paper attempts to deal with the aforementioned question. The measurement method has been thoroughly analyzed as well as the measurement test bed. Camera components (such as detector and optics) have also been analyzed and their key parameters have been measured, including noise figures of the entire system. Laboratory measurements are the most precise method used to determine range parameters of a thermal camera. However, in order to obtain reliable results several important conditions have to be fulfilled. One must have the test equipment capable of measurement accuracy (uncertainty) significantly better than the magnitudes of measured quantities. The measurements must be performed in a controlled environment thus excluding the influence of varying environmental conditions. The personnel must be well-trained, experienced in testing the thermal imaging devices and familiar with the applied measurement procedures. The measurement data recorded for several dozen of cooled thermal cameras (from one of leading camera manufacturers) have been the basis of the presented analysis. The measurements were conducted in the accredited research laboratory of Institute of Optoelectronics (Military University of Technology).
The paper presents some aspects of muzzle flash detection using low resolution polycrystalline PbSe 32×32 and 80×80 detectors FPA operating at room temperature (uncooled performance). These sensors, which detect in MWIR (3 - 5 microns region) and are manufactured using proprietary technology from New Infrared Technologies (VPD PbSe – Vapor Phase Deposition of polycrystalline PbSe), can be applied to muzzle flash detection. The system based in the uncooled 80×80 FPA monolithically integrated with the CMOS readout circuitry has allowed image recording with frame rates over 2000 Hz (true snapshot acquisition), whereas the lower density, uncooled 32×32 FPA is suitable for being used in low cost infrared imagers sensitive in the MWIR band with frame rates above 1000 Hz. The FPA detector, read-out electronics and processing electronics (allows the implementation of some algorithms for muzzle flash detection) of both systems are presented. The systems have been tested at field test ground. Results of detection range measurement with two types of optical systems (wide and narrow field of view) have been shown. The theoretical analysis of possibility detection of muzzle flash and initial results of testing of some algorithms for muzzle flash detection have been presented too.
Range parameters are main factors in assessing the performance of observation devices. They can be determined on the basis of computer simulations, field or laboratory measurements, with the latter method being the most reliable and practical. The paper presents the methods used for the determination of detection, recognition and identification ranges based on well-known Johnson criteria and recently emerged TTP model. Theoretical background for both approaches are given, and the laboratory test stand is described together with brief methodology adopted for the measurements of selected, necessary characteristics of a tested observation system. The measurement results are presented and the calculated ranges for a selected set of IR cameras are given, obtained on the basis of both Johnson criteria and TTP model. Finally the results are discussed and the final thoughts on the TTP model application are presented.
Uneven response of particular detectors (pixels) to the same incident power of infrared radiation is an inherent feature of microbolometer focal plane arrays. As a result an image degradation occurs, known as Fixed Pattern Noise (FPN), which distorts the thermal representation of an observed scene and impairs the parameters of a thermal camera. In order to compensate such non-uniformity, several NUC correction methods are applied in digital data processing modules implemented in thermal cameras. Coefficients required to perform the non-uniformity correction procedure (NUC coefficients) are determined by calibrating the camera against uniform radiation sources (blackbodies). Non-uniformity correction is performed in a digital processing unit in order to remove FPN pattern in the registered thermal images. Relevant correction coefficients are calculated on the basis of recorded detector responses to several values of radiant flux emitted from reference IR radiation sources (blackbodies). The measurement of correction coefficients requires specialized setup, in which uniform, extended radiation sources with high temperature stability are one of key elements. Measurement stand for NUC correction developed in Institute of Optoelectronics, MUT, comprises two integrated extended blackbodies with the following specifications: area 200×200 mm, stabilized absolute temperature range +15 °C÷100 °C, and uniformity of temperature distribution across entire surface ±0.014 °C. Test stand, method used for the measurement of NUC coefficients and the results obtained during the measurements conducted on a prototype thermal camera will be presented in the paper.
Range parameters of observation devices can be determined on the basis of numerical simulations (NVTherm) or on the
basis of measured characteristics. Those measurements can be conducted in both laboratory and field conditions. It is,
however, difficult to carry on reliable field measurements of range parameters because they are strongly depended on
atmospheric conditions. Thus the laboratory measurements are more favorable option. Analysis of literature and catalogue specifications reveal, that range parameters are given mainly on the basis of Johnson criteria or TTP model. The Johnson criteria has been used since the 50s and most of catalogue range specifications are determined according to it. There are also NATO standards, which describe the measurement procedures and methodology required to define the detection, recognition and identification ranges for standard NATO targets. For the determination of range parameters the following device characteristics must be known: minimal resolvable temperature for thermal imaging devices and minimal resolvable contrast for VIS devices. The TTP model offers a new approach to the determination of range characteristics of observation devices. It has been developed by U.S. Army’s Night Vision and Electronic Sensors Directorate since the year 2000. It was created because the modified Johnson criteria did not yield reliable results in case of modern systems with digital image processing. In order to determine the range parameters using TTP model, the modulation transfer function MTF, presample MTF function, and 3D noise of a tested system must be known as well as its basic design data as optical magnification and display type. The paper describes the measurement stand, measurement methodology and the procedure for the determination of range parameters. The results for thermal and VIS cameras are also presented, and they are analyzed and compared with the results obtained from current methods, including the measurement uncertainty figures. Some suggestions on
the methodology of measurements are also given.
There are many separated infrastructural objects within a harbor area that may be considered „critical", such as gas and oil terminals or anchored naval vessels. Those objects require special protection, including security systems capable of monitoring both surface and underwater areas, because an intrusion into the protected area may be attempted using small surface vehicles (boats, kayaks, rafts, floating devices with weapons and explosives) as well as underwater ones (manned or unmanned submarines, scuba divers). The cameras used in security systems operate in several different spectral ranges in order to improve the probability of detection of incoming objects (potential threats). The cameras should then have adequate range parameters for detection, recognition and identification and those parameters, both measured and obtained through numerical simulations, will be presented in the paper. The range parameters of thermal cameras were calculated using NVTherm software package. Parameters of four observation thermal cameras were also measured on a specialized test stand at Institute of Optoelectronics, MUT. This test stand makes it also possible to test visual cameras. The parameters of five observation cameras working in the visual range were measured and on the basis of those data the detection, recognition and identification ranges were determined. The measurement results and simulation data will be compared. The evaluation of range parameters obtained for the tested camera types will define their usability in the real security system for the protection of selected critical infrastructure of a seaport.small surface objects (such as RIB boats) by a camera system and real test results in various weather conditions will also be presented.
Every naval vessel can be detected and identified on the basis of its characteristics. The reduction of signature or
matching it to the surrounding environment are one of the key tasks regarding survivability on a modern battlefield. The
typical coatings applied on the outer surfaces of vessels are various kinds of paints. Their purpose is to protect the hull
from aggressive sea environment and to provide camouflage in the visual spectrum as well as scatter and deflect
microwave radiation. Apart from microwave and visual, infrared is most important spectral band used for detection
purposes. In order to obtain effective protection in infrared the thermal signature of a vessel is required. It is determined
on the basis of thermal contrast between a vessel itself and actual background and depends mostly on radiant properties
of the hull. Such signature can be modified by altering apparent temperature values or the directions, in which the
infrared radiation is emitted. The paper discusses selected methods of modification of vessel's infrared signature and
effectiveness of infrared camouflage. Theoretical analyses were preceded by experimental measurements. The
measurement-class infrared cameras and imaging spectroradiometers were used in order to determine the radiant
exitance from different surface types. Experiments were conducted in selected conditions taking into account solar
radiation and radiation reflected from elements of the surrounding scenery. Theoretical analysis took into account radiant
angular properties of a vessel hull and attenuation of radiation after passing through the atmosphere. The study was
performed in MWIR and LWIR ranges.
TTP (Targeting Task Performance) model is widely used for the estimation of theoretical performance of observation
devices. It is used, for example, in the NVTERM software and makes it possible to determine the detection, recognition
and identification ranges for a standard target types on the basis of known technical parameters of analyzed device.
Many theoretical analysis concerning TTP model can be found, as well as a few experimental, field test results. However
the usability of the TTP model for the calculation of range parameters on the basis of laboratory test results has not been
widely analyzed. The paper presents an attempt to apply TTP model for the estimation of range parameters of thermal
cameras using laboratory measurement results of camera properties. The test stand consists of an IR collimator, a
standard IR source, a set of test targets and a computer with data acquisition card. The method used for the measurement
of aforementioned characteristics will be described and the algorithms used to finally estimate the range parameters of a
tested thermal camera using TTP model.
The increasing range of naval engagements results in development of camouflages applied on warships that mask their
signatures first in visible and next in and IR spectra. Camouflage applied on warships that mask their IR signatures is one
of the most basic countermeasure methods against attacks by heat-seeking missiles. A set of special coatings applied to
the ship's hull allows misidentification by enemies weapon and so make the ship harder to destroy. Thus the knowledge
on actual thermal contrast between the ship and surrounding background is required in order to provide an effective
antimissile defense. The paper presents selected aspects related to ship's camouflage realized by altering its thermal
signature as well as the results of radiometric measurement of thermal radiation of IR-masking coatings. Measurements
were performed using IR imaging spectrometers in near, medium and far infrared spectra. The presented measurement
results constitute the basis for the assessment of the effectiveness of IR masking methods and additionally provide the
opportunity to effectively simulate the properties of masking coatings and further to optimize their radiometric properties
in the infrared range.
The paper presents the concept of a multisensor system for perimeter protection, suitable for stationary and moving
objects. The system consists of an active ground radar and thermal and visible cameras. The radar allows the system to
locate potential intruders and controls an observation area for system cameras. The multi-sensor system concept ensures
significant improvement of the probability of intruder detection and reduction of false alarms, thus increasing the
functionality and performance of the whole system. Effective ranges of detection depend on the quality of the applied
sensors and the observed scene itself. One of the most important devices used in such systems are IR cameras. The paper
discusses the technical possibilities and limitations to use uncooled IR cameras in such a multi-sensor system for
perimeter protection. The role of IR cameras in the system was discussed as well as a technical possibilities to detect a
human being. The operational distances for perimeter protection are rather high, considering the performance of
commercially available thermal cameras. The required spatial resolutions for detection, recognition and identification
were calculated and then the detection ranges were estimated using NVTherm software. The results of analysis were
finally presented and the comparison of exemplary IR cameras.
In areas like military systems, surveillance systems, or industrial process control, more and more often there is a need to
operate in limited visibility conditions or even in complete darkness. In such conditions vision systems can benefit by
using thermal vision cameras. In thermal imaging an infrared radiation detector arrays are used. Contemporary infrared
detector arrays suffers from technological imprecision which causes that the response to uniform radiation results in
nonuniform image with superimposed fixed pattern noise (FPN). In order to compensate this noise there is a need to
evaluate detectors characteristics like responsivity and offset of every detector in array. Some of the detectors in cooled
detector arrays can be also defective. Signal from defective pixels has to be in such system replaced. In order to replace
defective pixels, there is a need to detect them. Identification of so-called blinking pixels needs long time measurement,
which in designed calibration stand is also possible. The paper presents the design of infrared detector array
measurement stand allowing measurement of mentioned parameters. Measurement stand was also used to evaluate
temporal noise of infrared detection modules. In article there is a description of optical system design and parameters of
used reference blackbodies. To capture images from camera modules a specially designed digital image interface was
used. Measurement control and calculations were made in specially written IRDiag software. Stand was used to measure
parameters for cameras based on cooled focal plane arrays from Sofradir. Results of two-point nonuniformity correction
are also presented.
Humans cannot objectively judge electro-optical imaging systems looking on an image of typical scenery. Quality
of the image can be bad for some people but good for others and therefore objective test methods and advanced
equipment are needed to evaluate these imaging systems. Test methods and measuring systems that enable reliable
testing and evaluation of modern thermal cameras, color and monochrome TV cameras, LLLTV cameras and image
intensifier systems are presented in this paper.
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