Imaging system range defines the maximal distance at which a selected object can be seen and perceived following surveillance task perception criteria. Thermal imagers play a key role in long-range surveillance systems due to the ability to form images during the day or night and in adverse weather conditions. The thermal imager range depends on imager design parameters, scene and transmission path properties. Imager range prediction is supported by theoretical models that provide the ability to check range performance, compare range performances for different systems, extend range prediction in field conditions, and support laboratory measurements related to range. A condensed review of the theoretical model’s genesis and capabilities is presented. We applied model-based performance calculation for several thermal imagers used in our long-range surveillance systems and compared the results with laboratory performance measurement results with the intention of providing the range prediction in selected field conditions. The key objective of the paper is to provide users with reliable data regarding expectations during a field mission.

Multi-sensor imaging systems using the global navigation satellite system (GNSS) and digital magnetic compass (DMC) for geo-referencing have an important role and wide application in long-range surveillance systems. To achieve the required system heading accuracy, the specific magnetic compass calibration and compensation procedures, which highly depend on the application conditions, should be applied. The DMC compensation technique suitable for the operation environment is described and different technical solutions are studied. The application of the swinging procedure was shown as a good solution for DMC compensation in a given application. The selected DMC was built into a system to be experimentally evaluated, both under laboratory and field conditions. The implementation of the compensation procedure and magnetic sensor integration in systems is described. The heading accuracy measurement results show that DMC could be successfully integrated and used in long-range surveillance systems providing required geo-referencing data.

Multi-sensor imaging systems have a very important role and wide applications in surveillance and security systems. In many applications, it is necessary to use an optical protective window as an optical interface connecting the imaging sensor and object of interest’s space; meanwhile an imaging sensor is mounted in a protective enclosure, providing separation from environmental conditions. Optical windows are often used in various optical and electro-optical systems, fulfilling different sometimes very unusual tasks. There are lots of examples in the literature that define optical window design for targeted applications. Through analysis of the various effects that follow optical window application in connection with imaging systems, we have suggested a simplified methodology and practical recommendation for how to define optical protective window specifications in multi-sensor imaging systems, using a system engineering approach. In addition, we have provided initial set of data and simplified calculation tools that can be used in initial analysis to provide proper window material selection and definition of the specifications of optical protective windows in multi-sensor systems. It is shown that although the optical window design seems as a simple task, it requires serious multidisciplinary approach.

The thermal management of a complex electro-optical system aimed for outdoor application is challenging task due to the requirement of having an air-sealed enclosure, harsh working environment, and an additional thermal load generated by sunlight. It is essential to consider the effect of heating loads in the system components, as well as the internal temperature distribution, that can have influence on the system life expectancy, operational readiness and parameters, and possibility for catastrophic failure. The main objective of this paper is to analyze internal temperature distribution and evaluate its influence on system component operation capability. The electro-optical system simplified model was defined and related thermal balance simulation model based on Solid Works thermal analysis module was set and applied for temperature distribution calculation. Various outdoor environment scenarios were compared to evaluate system temperature distribution and evaluate its influence on system operation, reliability, and life time in application environment. This work was done during the design process as a part of the electro-optical system optimization. The results show that temperature distribution will not be cause for catastrophic failure and malfunction operation during operation in the expected environment.

Imaging sensor development results, achieved in the past four decades, provide increased camera capabilities both in day and night conditions. Due to advanced camera performances, we are experiencing a wide application of the imaging sensors in various areas, e.g. machine vision, mobile technology, autonomous vehicle driving, smart city scenarios, and scientific imaging. Low light level sensitivity, supporting camera night vision capability, leads to new applications in the security systems. Accordingly, the new needs of the camera testing procedures appear. Advanced camera performances also require a new approach to imaging sensor and camera testing and parameter definition. The short review of the current achievements in the area of low light camera technology developments is presented as a basis to illustrate the importance of their application and proper metrological support development. The review of the most important low light camera parameters and related measurement and testing methods is set to point out the needs for new low light camera testing procedures development.

Uvod/cilj: Modulaciona funkcija prenosa (MTF) koristan je alat za analizu performansi sistema za obradu slike. Koristi se u dizajniranju elektrooptičkih (EO) sistema, pri proveri ciljanih parametara sistema, ali i u zadacima optimizacije testiranih sistema. Ova metodologija, zasnovana na teoriji linearnih sistema, omogućava da se analiza performansi složenih EO sistema podeli na podsisteme. MTF metodologija najpre je predstavljena i objašnjena, a zatim je prikazano merenje izvršeno u elektrooptičkoj laboratoriji. MTF merenja izvedena su na tri tipa kamera, u različitim spektralnim opsezima, nakon čega su rezultati upoređeni sa očekivanim modelima i teorijskim ograničenjima sistema za obradu slike. Metode: Laboratorijska merenja i teorijska matematička izračunavanja. Rezultati: Na osnovu laboratorijskih i teorijskih rezultata dodatno su analizirani rezultati merenja. Zaključak: Merenja su dokazala da izračunata granična frekvencija i krivulja MTF predstavljaju granicu za stvarne performanse sistema. Potvrđeno je da MTF može biti pogodan za pronalaženje ograničenja i uskih grla sistema, kao i za poboljšanje ukupnih performansi sistema.