The Value of Near Wave Infrared Technologies - Research Paper Example

Near Wave Infrared Technology and Applications Institution Name Table of Contents Table of Contents 2 Introduction 3 Background 4 Sensor-based NIR systems 5 PIR motion-based detector 5 Pyroelectric Infrared Sensor (PIR) 6 Passive infrared sensor operating principles 6 Application of motion-based sensors near wave infrared sensors 7 Vision-based infrared systems 8 Infrared security cameras 8 Thermal imaging in infrared cameras 8 Night-vision performance 9 Rationale for using Infrared security cameras 10 Application of vision-based systems 10 Advantages of near wave infrared technologies 11 Disadvantages of near wave infrared technologies 12 Conclusion 13 References 15 Introduction The near infrared (NIR) light is a type of light with longer wavelength than the visible spectrum of between 700 and 1,100 nanometres that is outside the range of visible spectrum. Normally, a narrow range of wavelengths, also known as the near wave infrared, from between 380 nanometres (violet) to 700 nanometres (red) is detectable by the human eye (Ariff et al., 2010). The human vision is limited to a small section of the electromagnetic spectrum known as visible light (See Figure 2). The near wave infrared technologies consist of surveillance cameras or motion detectors. Nahatkar et al. (2012) divided security systems into two categories depending on their input mechanisms. These include the sensor-based systems that use simple movement or contact sensor to detect intrusion into a protected area and secondly, the vision-based systems, which consist of security cameras such as infrared imagery that use video or image capture to obtain input data on intrusion. Bangali and Shaligram (2013) suggested that the sensor-based systems use NIR motion sensors to detect intrusion. The vision-based sensors use a transmitter to transmit beams of invisible infrared light to a receiver that monitors signal and can detect changes in the signal through thermal imaging (Maeng et al., 2011). The sensor-based systems and vision-based systems use near wave infrared light in detection of intrusion (Sarhan (2013) Defence in Depth theory as an approach to protection of facilities for security as a discipline proposes a line of attack against unauthorised intrusion, destruction of assets, theft and protection of personnel and facilities. Expressed as a security theory, Coole and Brooks (2011) underpins Defence in Depth as critical for ensuring detection, deterrence, delay, response and recovery. Defence in Depth, according to Coole and Brooks (2014), is based on the premise that protection of assets should be enclosed by succession of barriers to limit penetration of unauthorised access and appropriate response and recovery. Indeed, Coole et al. (2012) argued that the Defence in Depth approach follows the systems approach, which Young and Leveson (2014) hypothesises that individual system components are also effective when they work as a whole. In which case, the infrared cameras and motion sensors are part of the security system whose effectiveness depends on other physical barriers, such as the wall, windows, human barriers, and perimeter fence (Beardsley, 2013). Hence, the functions of detect, delay and response are what drives the value of near wave infrared technologies. Therefore, this paper argues that near wave infrared technologies follow a systems approach that integrates procedures, people and equipment into the security or barrier system to ensure detection, deterring, delay and response to intrusions. Background Infrared radiation (IR) was unheard of until about 1800 when Herschel experiment created a monochromator that uses a thermometer to detect and measure energy distribution in sunlight. Traditionally, near wave infrared technologies have been associated with night vision and remotely controlling function. Until recently, the security applications were largely based on thermal imaging as surveillance and alerting military systems. Today, they are used in making motion detectors to detect intrusion. Infrared (IR) technology has been dedicated to security and surveillance, particularly, in the military field since its first application. Thermal-infrared imaging is applied extensively for military purposes, such as target acquisition, night vision, surveillance, environmental monitoring, homing and tracking. Hamamatsu (2011) suggests that a typical system for detection of infrared radiation can often configured as indicated below. Both the sensor-based systems and the vision-based sensors use the configuration. Figure 1: Typical system for detection of infrared radiation The infrared source includes silicon carbide, tungsten lamps or blackbody radiation. Infrared lasers that radiate infrared energy of a certain wavelength may as well be used. Transmission media include the optical fibres, atmosphere or vacuum. In order to focus or converge infrared radiation, optical lenses or sensors are used, although depending on their wavelengths (Hamamatsu, 2011). Sensor-based NIR systems The sensor-based systems use simple movement or contact sensor to detect intrusion into a protected area. Example includes passive infrared (PIR) motion detector. PIR motion-based detector PIR-based motion detectors are designed for detecting movement of animals, people or objects. Mostly, they are used in automatically-activated lighting systems and burglar alarms. Individual PIR sensor senses the changes in the degree of infrared radiation imposed upon it. The radiation varied dependent on the surface and temperature properties of the objects within the NIR system’s sensor field of view. Once an intruder passes in front of the background, such as a fence or wall, the temperature in the sensor’s field of view rises from room to body temperature. The sensor then converts the resultant change in the received infrared radiation into a change in the output voltage. This triggers detection. A typical protected facility such as an office space may have infrared motion detectors mounted to the ceiling, wall or overlooking perimeter fence. Once installed in place, the motion detectors use infrared light to create thermal image of the protected space (Ahmed et al.2011). Therefore, since each component in the office such as walls, floors, furniture and fabric has particular heat signature, the passive infrared detector develops a normal image of the room. When the image changes when a person, object or animal enters the protected area, the detectors identifies the image change. Signal is then sent to the security system’s control panel. Pyroelectric Infrared Sensor (PIR) Dhake and Borde (2014) noted that Pyroelectric Infrared Sensor (PIR) is essentially made of Pyroelectric Sensors designed to create electric signal in response to shifts in the incidental thermal radiation. The sensors’ functioning is based on the principle that living organisms radiate low-level of radiation. The sensor’s detection range is between 3 metres and 7 metres. In order to modify the sensor’s field of view (FOV), the detector has lenses at the front. To cover more extensive area, the detection lenses are split up into multiple sections. Each of the sectors is a Fresnel lens that condenses light, as a result, providing a range of NIR to the sensor. This allows the sensor to span over several degrees of width. Passive infrared sensor operating principles Otula et al. (2013) describe Passive infrared sensor as an electronic sensor designed to measure infrared light from objects within the configured field of view. All objects radiating temperatures above the absolute zero also radiate heat energy in the form of radiation. Since the radiation radiates wavelengths, it is invisible to the human eye. These wavelengths can be detected by electronic devices, such as NIR systems. Hers et al. (2013) explains that the term passive is used as it denotes the fact that passive infrared sensors do not radiate or generate any form of energy for purposes of detection. Instead, they function by detecting the energy radiated by other objects. Hence, it is significant to explain that the infrared sensors do not measure or detect heat per se. Instead, they detect the infrared radiation given off by objects that are different but usually associated with the objects temperature. Rogalski and Chrazanowski (2002) indicated that the infrared radiation uses the sensor face or front of the sensor as way of entry. At the centre of the passive infrared sensor, there is a solid state sensor manufactured from pyroelectric materials that can generate energy when exposed to heat. Application of motion-based sensors near wave infrared sensors To conclude, the motion-based infrared sensors detect intrusion and alert the human security personnel using an alarm system, who in turn respond to the intrusion. Oludele et al (2009) advises that interior intrusion detection measures are devised to detect penetration through perimeter barriers. According to Fema (2008), an interior sensor can be installed to a facility’s interior space or perimeter fence. Generally, an interior asset is a resource or facility contained within a space with sensors that protect the flows, walls and ceilings. The infrared sensor, which must activate once it detects intrusion, is an example of interior sensor. Vision-based infrared systems The vision-based infrared systems consist of security cameras such as infrared imagery that use video or image capture to obtain input data on intrusion or crime activities. Example includes the cameras with passive infrared (PIR) sensors such as smart CCTV cameras (Abidi et al., 2008). Infrared security cameras Nelson (2014) explains that infrared security camera systems consist of a set of infrared CCTV cameras (or night vision security cameras) that allows security personnel to monitor protected spaces with no or limited light. According to Fu et al. (2012), their key strength is the capacity to capture videos or images in no or low light. These cameras have infrared lens or sensors positioned at the outer edge of camera lens, which allow the camera to capture images in pitch darkness. Thermal imaging in infrared cameras Infrared imaging technology is an advanced technique for detecting and analysing scenes often imperceptible by the human eye (Leitner, 2013). The near wave technology cameras use the nightglow concept of viewing objects even when it is dark (Fu et al., 2012). Infrared CCTV cameras are able to detect light beyond the limited range of the human eye (730-110 nanometre). This makes them applicable for night-time surveillance. These NIR thermal imaging cameras capture heat radiated by warm objects, which stand out in cool backgrounds. Within this background, warm blooded animals and humans are easily visible during night or day (FLIR, 2014). Figure 2 below shows the spectral response, or the visible light of a typical human eye with luminous radiometric conversion. Figure 2: Visible light colour spectra (Honeywell, 2013). Night-vision performance The Johnson Criteria, proposed by Johnson (2005), can be used to explain the night-vision performance. In Honeywell’s (2013) view, the criteria present security personnel with a standard approach for evaluation of night vision performance in order to achieve excellent night-vision once infrared illumination is understood. As stated by Borissova and Mustakerov (2009), in order to solve the problem of night-vision, based on the Johnson Criteria, night-time performance parameters have to be clearly described on what is to be detected with the camera. The Criteria proposes four simple classifications called the DCRI, for Detection, Classification, Recognition and Identification (Yeh et al., 2004). Detection implies that human-sized objects can be established to be present at a scene. Classification means that an object can be classified as human, animal or object. Recognition implies that the human-sized object is determined to be a threat. Identification means that the human-sized object is positively identified to be a specific individual (AlliedScientific, 2014). Rationale for using Infrared security cameras The challenge to security professional is ensuring the video footage is effective in 24 hours a day, and 7 days a week across the year. Night vision is central to attaining this objective. Krapels (2007) explains that when it comes to night vision, the capacity to see in darkness, whether through technical or biological means, is ensured by combining two approaches, sufficient intensity range and adequate spectral range. Intrusions or illegal activities mostly happen in the cover of the night when it is dark, since monitoring protected areas to detect intruders without a means of visual sight is a challenge (Fletcher, 2011). While spotlights can be used to observe what is happening, they may tend to modify the very behaviour being observed. It is based on this premise that cameras that employ the use of near wave technology come in handy. According to Ariff et al. (2010), infrared camera enables surveillance personnel to observe the intruders at safe and unnoticeable distance and to monitor their activities as they happen, yet without or with minimal artificial lighting. Consistent with the view, Zeng et al. (2014) suggested that a suitable method of performing night surveillance is application of night vision technique, in particular near-infrared (NIR) cameras is critical. The cameras operate in low-light environments since the system can provide own NIR light source. Application of vision-based systems To conclude, the vision-based infrared systems intrusion alerts the human security personnel who in turn respond to the intrusion. Rogalski and Chrazanowski (2002) explained that Infrared technology is used in security surveillance activities, specifically during night surveillance. Currently, infrared technology is divided into two types, namely the infrared photography camera and the thermal camera. The photography cameras use NIR sensor such as the night vision technology, while the thermal cameras apply the heat sensor concept (Krapels et al., 2007). As explained by Ariff et al. (2010), the night vision is sensitive to infrared source. Additionally, it is not detectable by the human eye. It can therefore show visuals in dark places. The infrared filters are used for enhancing the night vision. They are also designed for photographic effect with a range of wavelengths (700-925 nm). This makes them effective for monitoring protected environments at night when there is limited light. Advantages of near wave infrared technologies Using near wave infrared technologies in motion detection has several advantages. Ohaname et al. (2012) noted that when active infrared is used as a sensor to detect intrusion, it ensures fast response. Additionally, it is not affected by acoustic or mechanical noise. Using vision-based near wave infrared technologies in image capturing has also several advantages. Since atmospheric phenomenon referred as night sky radiance discharges between five and seven time more illumination compared to the light from the stars, with the infrared camera and the night radiance (or nightglow), objects can be viewed with great clarity during moonless nights (Chong, 2004). Additionally, resolutions of the sensor tend to be high, although light sources such as on-coming cars or spotlights can cause glares, hence resulting to sensor blooming. The sensors can be made to be extremely sensitive, hence allowing them to count individual photons (SensorsUnlimited, 2014). Additionally, NIR systems improve the view, just within the range of illuminator employed for use (Kallhammer, 2006). Kallhammer (2006) also argues that the key benefit of NIR systems is that they are cost-effective. A synergy potential is also realised from incorporating the hardware of the NIR night-vision system with related functions, such as warning on intruders. The dual functionality improves the cost advantage for the NIR systems. Disadvantages of near wave infrared technologies Ohaname et al. (2012) expressed concern about the use of motion-based new wave infrared technologies in intruder detection. In their view, the system is only effective for use in detecting intrusion in idle or still areas. In which case, it is not appropriate for use in places such as malls that are filled with human movement. In image capturing, the vision-based infrared systems have several downsides. While infrared waves travel in a straight line, they are vulnerable to reflectance, refraction, diffraction, and absorption. These affect the quality of thermal imaging and effectiveness of CCTV cameras in detection of crime. Koretsky et al. (2013) explains that reflectance is the process where the direction that happiness at the surface of an object is reversed. Refraction refers to the shifting of the angle that happens at the boundaries of various surfaces. Usually, various wavelengths have different refraction angles (Koretsky et al., 2013). Diffraction refers to the deflection that happens at the edges of observable objects. Absorption refers to tendency of the colour surfaces to absorb some light and reflect the remainder. Usually, a combination of these factors affects light, hence influencing the quality of CCTV lighting. Kallhammer (2006) pointed out that the NIR systems' detection range is dependent on the reflectivity, since different types of clothing may have different reflectivity. This means that detection distance is vulnerable to impairment. Each wavelength reacts differently to certain light. In regards to the night vision, the dampness, fog and light disturbances may affect the image and, as a result, be subjected to poor imaging (Nelson, 2014). This may affect the visual image of the system. At the same time, when the infrared filter is used, it helps in reducing and optimising the effects of such disturbances. Based on the systems approach, a major disadvantage is that these systems cannot work without the human element. As a solution to some of the image problems, Kallhammer (2006) suggests that suitable image processing may offer significant improvement to the image appearance, where the images will have to most gain. In his view however, elimination of the high degree of clutter in NIR images using image processing stills remains to be seen. Despite this, with sufficient intruder detection performance, the image may not often be visible. Additionally, increased clutter level in NIR systems may not be an issue anymore. Conclusion Near wave infrared technologies follow a systems approach that integrates procedures, people and equipment into the security or barrier system to ensure detection, deterring, delay and response to intrusions. This is mainly because they cannot function independently to ensure detection, deterring, delay and response to intrusions in order to ensure Defence in Depth. Essentially, the near wave infrared technologies divided security systems into two categories depending on their input mechanisms. They therefore consist of surveillance cameras or motion detectors. The sensor-based systems use simple movement or contact sensor to detect intrusion into a protected area while the vision-based systems consist of security cameras such as infrared imagery that use video or image capture to obtain input data on intrusion. As interior intrusion detection measures, they are designed to detect penetration through perimeter barriers by complementing other physical security elements, such as the human security personnel and the alarm system. The motion-based infrared sensors are used in making motion detectors that detect intrusion and alert the human security personnel through an alarm system, who in turn respond to the intrusion. Further, the sensor-based systems use NIR motion sensors to detect intrusion. The vision-based sensors use a transmitter to transmit beams of invisible infrared light to a receiver that monitors signal and can detect changes in the signal through thermal imaging. When an intruder passes in front of the background such as a fence or wall, the temperature in the sensor’s field of view rises from room to body temperature. The sensor then converts the resultant change in the received infrared radiation into a change in the output voltage. This triggers detection. Using near wave infrared technologies in motion detection ensures fast response to intrusion. Additionally, they are not affected by acoustic or mechanical noise. They also have high resolution. However, the systems are only effective for use in detecting intrusion in idle or still areas. They are also vulnerable to reflectance, refraction, diffraction, and absorption. These affect the quality of thermal imaging and effectiveness of CCTV cameras in detection of crime. References Abidi, B., Naragam, N., Yao, Y. & Abidi, M. (2008). Survey and analysis of multimodal sensor planning and integration for wide area surveillance. ACM Computing Surveys, 41(1). article 7 Ahmed, A., Ahmed, T., Ullah, S. & Islam. M. (2011). Controlling and securing a Digital Home using Multiple Sensor Based Perception system Integrated with Mobile and Voice technology. International Journal of Information and Communication Technology Research 1(5), 189-196 AlliedScientific. (2014). White Paper: Short Wave Infrared (SWIR) for Surveillance Applications in Defense. Retrieved: Ariff, M., Majid, Z., Setan, H. & Chong, A. (2010). Near-Infrared Camera For Night Surveillance Applications. Geoinformation Science Journal 10(1), 38-48 Bangali, J. & Shaligram, A. (2013). Design and Implementation of Security Systems for Smart Home based on GSM technology. International Journal of Smart Home 7(6), 201-208 Beardsley, J. (2013). Security 101: Understanding the Common Layered Security Concept. The Valley Business Journal Borissova, D. & Mustakerov, I. (2009). A generalized optimization method for night vision devices design considering stochastic external surveillance conditions. Applied Mathematical Modelling 33(11), 4078-4985 Chong, A. (2004). Digital near-infrared camera for 3D Spatial Data Capture. Paper Presented at SIRC 2004 – The 16th Annual Colloquium of the Spatial Information Research Centre University of Otago, Dunedin, New Zealand November 29th-30th 2004 Coole, M., P., & Brooks, D., J. (2011). Mapping the organizational relations within physical security’s body of knowledge: A management heuristic of sound theory and best practice. Proceedings from the fourth Australian security and intelligence conference. Perth. Western Australia Coole, M. & Brooks, D. (2014). Do Security Systems Fail Because of Entropy? Journal of Physical Security 7(2), 50-76 Coole, M., Corkill, J. & Woodward, A. (2012). Defence in Depth, Protection in Depth and Security in Depth: A Comparative Analysis Towards a Common Usage Language. Originally published in the Proceedings of the 5th Australian Security and Intelligence Conference, Novotel Langley Hotel, Perth, Western Australia, 3rd-5th December, 2012 Corsi, C.(2012). Infrared: A Key Technology for Security Systems. Advances in Optical Technologies, 1-15 Dhake, P. & Borde, S. (2014). Embedded Surveillance System Using PIR Sensor. International Journal of Advanced Technology in Engineering and Science 2(1), 31-36 Fema. (2008). Incremental Protection for Existing Commercial Buildings from Terrorist Attack: Providing Protection to People and Buildings. Risk management Series Fema 459 Fletcher, P. (2011). IS CCTV Effective in Reducing Anti-Social Behaviour. Internet of Criminology 1-41 FLIR (2014). IR Spectral Bands and Performance. Retrieved: Fu, Q., Wang, J., Lin, G., Suo, H. & Zhao, C. (2012). Short-Wave Near-Infrared Spectrometer for Alcohol Determination and Temperature Correction. Journal of Analytical Methods in Chemistry 1-7 Hamamatsu (2011). Characteristics and use of infrared detectors. Retrieved: Hers, V., Corburgy, D., Joslet, L., Hermant, P., Demarteaue, J. & Hermanne, J. (2013). New concept using Passive Infrared (PIR) technology for a contactless detection of breathing movement: a pilot study involving a cohort of 169 adult patients. J Clin Monit Comput 1(1), 1-10 Honeywell. (2013). Honeywell Night Vision Security. Retrieved: Kallhammer, (2006). Night Vision: Requirements and Possible Roadmap for FIR and NIR Systems. Retrieved: Johnson, C. (2005). The Role of Night Vision Equipment in Military Incidents and Accidents. retrieved: Koretsky, G., Nicoll, J. & Taylor, M. (2013). A Tutorial on Electro-Optical/ Infrared (EO/IR) Theory and Systems. IDA Document D-4642 January 2013 Krapels, K, Driggersm R. & Garcia, J. (2007). Performance of infrared systems in swimmer detection for maritime security. Optics Express 15(19), 1-14 Leitner, M. (2013). Crime Modeling and Mapping Using Geospatial Technologies. New York: Springer Science and Business Media Maeng, H., Choi, H., Park, U., Lee, S., Jain, A. (2011). NFRAD: Near-Infrared Face Recognition at a Distance. International Joint Conf. Biometrics, Washington D.C., October, 2011 Nahatkar, S., Gaur, A. & Pattewar, T. (2012). Design of a Home Embedded Surveillance System with Pyroelectric Infrared Sensor & Ultra-Low Alert Power. International Journal of Advanced Research in Electronics and Communication Engineering 1(3), 86-90 Nelson, B. (2014). Near Infrared Camera Integrated Into James Webb Space Telescope. BizJournals. Retrieved: Ohaname, C., Azubogu, A., Ifeagwu, E. & Ohaname, L. (2012). Design and Implementation of an IP-Based Security Surveillance System. IJCSI International Journal of Computer Science Issues 9(1), 391-400 Oludele, A., Ogunnusi A., Omole O. & Seton O. (2009). Design of an Automated Intrusion Detection System incorporating an Alarm. Journal of Computing, 1(1), 149-157 Otula, G., Otwori, S. & Ogingo, O. (2013). PIR and GSM Based Buglar Security System. Project is submitted to the department of Electrical and Electronic Engineering in partial fulfilment for the award of Bachelor of Science degree in Telecommunication and Information Engineering at Dedan Kimathi University Of Technology Rogalski, A. & Chrazanowski, K. (2002). Infrared Devices and Techniques. Opto-Electronics Review 10(2), 111-136 Sarhan, Q. (2013). An Integrated Real-Time Vision Based Home Security System. International Journal of Advancements in Research & Technology 2(5), 331-336 SensorsUnlimited (2014). Why SWIR? What is the Value of Shortwave Infrared? Retrieved: Yeh, S., Lin, H., Shie, W. & Lee, W. (2004). The Application of Security Mechanisms Based on Wireless Infrared Data Communications with IrDA. Journal of Information, Technology and Society 1(1) 89-93 Young, W. & Leveson, N. (2014). An Integrated Approach to Safety and Security Based on Systems Theory. Communications Of The ACM. 57(2), 31-35 Zeng, S., Amandus, H.E., Amendola, A.A., Newbraugh, B.H., Cantis, D.M. and Weaver, D. (2014). Minimum Requirements for Taxicab Security Cameras. Journal of Transportation Technologies, 4, 216-255. Read More

Therefore, this paper argues that near wave infrared technologies follow a systems approach that integrates procedures, people and equipment into the security or barrier system to ensure detection, deterring, delay and response to intrusions. Background Infrared radiation (IR) was unheard of until about 1800 when Herschel experiment created a monochromator that uses a thermometer to detect and measure energy distribution in sunlight. Traditionally, near wave infrared technologies have been associated with night vision and remotely controlling function.

Until recently, the security applications were largely based on thermal imaging as surveillance and alerting military systems. Today, they are used in making motion detectors to detect intrusion. Infrared (IR) technology has been dedicated to security and surveillance, particularly, in the military field since its first application. Thermal-infrared imaging is applied extensively for military purposes, such as target acquisition, night vision, surveillance, environmental monitoring, homing and tracking.

Hamamatsu (2011) suggests that a typical system for detection of infrared radiation can often configured as indicated below. Both the sensor-based systems and the vision-based sensors use the configuration. Figure 1: Typical system for detection of infrared radiation The infrared source includes silicon carbide, tungsten lamps or blackbody radiation. Infrared lasers that radiate infrared energy of a certain wavelength may as well be used. Transmission media include the optical fibres, atmosphere or vacuum.

In order to focus or converge infrared radiation, optical lenses or sensors are used, although depending on their wavelengths (Hamamatsu, 2011). Sensor-based NIR systems The sensor-based systems use simple movement or contact sensor to detect intrusion into a protected area. Example includes passive infrared (PIR) motion detector. PIR motion-based detector PIR-based motion detectors are designed for detecting movement of animals, people or objects. Mostly, they are used in automatically-activated lighting systems and burglar alarms.

Individual PIR sensor senses the changes in the degree of infrared radiation imposed upon it. The radiation varied dependent on the surface and temperature properties of the objects within the NIR system’s sensor field of view. Once an intruder passes in front of the background, such as a fence or wall, the temperature in the sensor’s field of view rises from room to body temperature. The sensor then converts the resultant change in the received infrared radiation into a change in the output voltage.

This triggers detection. A typical protected facility such as an office space may have infrared motion detectors mounted to the ceiling, wall or overlooking perimeter fence. Once installed in place, the motion detectors use infrared light to create thermal image of the protected space (Ahmed et al.2011). Therefore, since each component in the office such as walls, floors, furniture and fabric has particular heat signature, the passive infrared detector develops a normal image of the room. When the image changes when a person, object or animal enters the protected area, the detectors identifies the image change.

Signal is then sent to the security system’s control panel. Pyroelectric Infrared Sensor (PIR) Dhake and Borde (2014) noted that Pyroelectric Infrared Sensor (PIR) is essentially made of Pyroelectric Sensors designed to create electric signal in response to shifts in the incidental thermal radiation. The sensors’ functioning is based on the principle that living organisms radiate low-level of radiation. The sensor’s detection range is between 3 metres and 7 metres. In order to modify the sensor’s field of view (FOV), the detector has lenses at the front.

To cover more extensive area, the detection lenses are split up into multiple sections. Each of the sectors is a Fresnel lens that condenses light, as a result, providing a range of NIR to the sensor.

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