Efficacy of Detection Sensor Technologies - Literature review Example

An Evaluation of the Efficacy of Detection Sensor Technologies Student’s Name Institution Affiliation An Evaluation of the Efficacy of Detection Sensor Technologies Introduction Detention sensor technologies find application in different fields mainly as a proactive measure against specific risks or incidences. Many detection sensor technologies capitalize on specificity and accuracy as a measure of efficacy. Presently, there are many types of detection sensor technologies in the market. According to Fay (2007), dual detection technologies are designed to lessen fake distress notifications. The principle behind this detection system is that an alarm will not go off until both sensors have recognized an event. Moreover, the efficacy of the dual detection technologies depends on the how the system is combines their individual strengths to achieve better functionality. Currently, dual detectors are available in the market but many experts feel that their efficacy may not be as high as theorized. Therefore, this discussion looks at the principles of these detection systems and the extent to which they are effective. Dual Technology Sensors The dual technology sensors combine two sensors techniques to achieve greater functionality. One such sensor is the passive infrared sensor in combination with another sensor technique such as microwaves. As the name suggests, it detects infrared radiation of lying between the range of 0.45 and 0.75 micrometers. According to Garcia (2008), this type of sensors finds wide application volumetric detection. It works by detecting the temperature differences in the environment or interception of the rays. One of the ways it does this is by reacting to the infrared rays transmitted by an object in the environment. For instance, it can respond to the heat energy emitted by the human body thereby detecting presence (Kaushik & Celler, 2006). When detecting obstruction, the sensor reacts to the changes in milieu radiation. The system can also sense movements. The PIR detection unit is capable of segmenting recognition patterns and sending electrical signals that communicate movement within the environment. To achieve this level of functionality, the system uses logic circuitry to differentiate between possible scenarios or events. The detection unit sets off the alarm if the received signal pattern does not match any of the programmed sets. Consequently, it means that any object that can cause a temperature differential within the environment is likely to trigger the alarm. Also, the system is likely to be set off by any rapid localized transmission changes. The underlying principle of this type of sensor is the magnitude of the heat difference between the obstructing object and the milieu. The system has a minimum resolvable temperature that is considered appropriate. Otherwise, a drastic thermal gradient sets out a different milieu energy pattern. Different elements in the environment could create hot spots, thereby interfering with the efficacy of the detection system. For instance, if there is heater in a room installed with a PIR sensor, switching it on could create a rapid temperature changes that could set off a bogus distress call. Also, simple events such as intense sunrays streaming in from a window can use enough temperature difference to trigger a false alarm. Lastly, this detection system is not animal proof. Insects and pets can easily set off a false distress signal. Vibrations too can set off incorrect alarms. This is because the vibrations can cause thermal sources to seem as interference activities, hence, setting off the distress signal. Also, electromagnetic fields can affect the alarm systems (Moghavvemi & Seng, 2004). Simple gadgets such as hand held radios are capable of causing significant electromagnetic disturbances that could compromise the system. Additionally, poor housekeeping practices could compromise the system. For instance, sizeable amounts of garments or any other wrapper materials could defeat the sensor. Also persons moving in slow motion can beat the system. The explanation for this type of reaction is that the system’s field view can be distracted. Garcia (2008) notes that simple techniques such as tape masking can distort the detection system’s field of view thereby converting to thwart accurate sensor function. The second type of sensors is the microwave sensor. According to Woodhouse (2006) microwave sensing technologies interacts well with other radiations. Objects are capable of emitting microwaves; the detection units expose these waves. The sensors detect electromagnetic radiation frequency of about 10GHz. There are different designs of microwave detectors; nonetheless, the working principle remains the same. For instance, monostatic microwaves both a transmitter and receiver and their detection scope is about 400 feet (Landoll, 2011). They offer restricted protection within a given space. The second design for microwave detection technologies is the bistatic microwave that has an independent transmitter and receiver. It has up to four times the detection scope as the monostatic designs and offers more than localized detection. Microwave sensors applied in motion detection in combination with PIR methods are most likely to have a monostatic design. In this type of configuration, the recognition system is likely to have one antenna that both broadcasts and receives the electromagnetic radiations. In order to detect intrusion, the system measures the magnitude of Doppler shift. Thus, if there is any movement within the sensor region, the detection unit measures the changes in Doppler frequency and if the aptitude and duration is abnormal then an alarm is set off. The system sends out radiation of known frequency and if there is no intrusion or obstruction then transmission sent back to the receiver is within the expected range of frequencies. However, the proximity to the sensor affects the frequency rates. Consequently, the system achieves optimum sensitivity when the target object is further away from the sensor compared to when it is closer. Secondly, the shape and design of the antennae affects the efficacy of the system because the detection patterns changes depending on the design (Kharkovsky & Zoughi, 2007). The accurate detection pattern has asymmetrical points at certain regions. Consequently, if an object happens to be within an undetectable region then the system may fail to recognize the intrusion. Despite the weaknesses, this system is beneficial because microwaves can penetrate surfaces such as walls, hence, offering a wider range of protection. On the other hand, this strength can expose the system to excessive interferences, hence, increasing the chances of false alarms. Thus, a combination of PIR and microwave sensors allows the system to achieve heightened sensitivity, thereby, reducing instances of false alarm (Babich & Martin, 2008). Also, the system is able to cover a wider detection scope, because microwaves penetrate walls and other surfaces. Additionally, the system to some extent is able to deal with interferences that are likely to trigger the alarm by ensuring that both sensors are configured to detect almost similar level of interference (Walsh, 2003). This is because the system has an in built microprocessor that needs a certain signature and signal intervals to deliver a recognition pattern interpretable by the system. Also, the type of circuitry for the system allows for individual timing protection incase either of the system should the detection unit malfunction. Thus, this type of system is more expensive than the ordinary detection technologies. The efficacy and functionality is improved. Fennelly (2004) notes that another type of dual technology sensor is the PIR/ultrasonic sensor. This type of sensor combines PIR and ultrasonic sensor mechanisms to achieve better detection. Dilouie (2008) advises that the decision to use this dual technology detection system needs to be based on the physical and functional capabilities of the system. For example, an ultrasonic detection systems are more suitable for areas with little movement activities. They are ideal for spaces with many corners but vibrations easily compromise them. The system can detect motion sent from an object to the sensor or form the sensor to the object. Moreover, it can detect similar levels of complete torso movement as the PIR sensors. Ultrasonic sensors apply the Doppler principle just like the microwave sensors. They recognize movement within a space by reflecting ultrasonic sound waves from the object to the detection unit. Thus, if there is a movement with the space, the detection system records a change in time taken for the sound waves to bounce back. This principle faces some challenges as they are affected by airflow. A strong air current will interfere with the bounce back time, thereby, triggering a false alarm or create a delay time that could compromise the overall security. Consequently, this detection unit works well only in spaces with far above the ground air drifts, lofty ceilings and open areas (Jones & Fielder, 2005). A combination of both PIR and Ultrasonic sensors provides protection against glass breaks, strong sensations, and force changes. The system consists of digital logic circuits (Honey, 2007). This type of circuit aids the system to identify sounds waves due to glass breaks, and vibrations. When detecting vibration the combination of both techniques works to confirm the presence of an intruder by responding to the resultant shock wave or force. When checking for pressure changes the system records any differential changes in pressure and in case there is any changes in normal and preset fluctuations then the alarm is set off. However, Morawski (2006) does not find this type of combinations effective. He points out that the ultrasonic detection is simple to distract, thereby, compromising the security. It is possible to deflect the ultrasonic waves using fabric; hence, an intruder can control these waves and navigate through the system. Moreover, reliance on sound waves is not effective as they could be manipulated to produce a configuration pattern recognizable by the system. They are easily triggered off; causing too many false alarms that can lead to one ignoring a real alarm. Recommendations It appears that the efficacy of dual detector systems is not as high as theorized. Therefore, to address some of the concerns and discredits it is critical that experts find efficient ways of combining both technologies to achieve better results. Currently, it appears that dual technologies are merged to build on both strengths rather than complement on individual vulnerabilities. Thus, there is need to look into ways how such combinations can complement each other by tackling each other’s weaknesses During the discussion, it is clear that the functionality of the detection systems is based on the extent of sensitivity of the system. Whereas this is the fundamental principle, there is need to consider whether better circuitry can improve functionality as opposed to modifying sensitivity only. There is need to compute improved logic circuits with better precision. If possible, inclusion of artificial intelligence technologies can help not only boost functionality but also efficacy of the entire system The dual sensors in the market have quite sophisticated but are not fool proof. There is need to investigate some of the techniques or events that are likely to affect efficacy. By understanding how these events affect the system, designers, and security experts can create more secure systems that cannot be compromised. Additionally, it is crucial to consider the concerns and suggestions of the end user regarding functionality in order to create a better performing product Conclusion Dual technology systems are a combination of two sensor methods that aim to increase sensitivity in order to detect an event or movements. The PIR/Microwave dual technology and the PIR/Ultrasound technologies provide enhanced security to different spaces. Each of the technologies capitalizes on its strengths to deliver better performance; however, based on the discussions it is evident that the dual combination has eliminated their individual weaknesses. Therefore, there is need look into ways to improve their circuitry, and incorporate other technologies in order to improve the efficacy of detection system. Taking up such recommendations will enable experts not only focus on combining different sensor methods to achieve greater strengths but to address the individual weaknesses of each system. References Babich, T. S., & Martin, C. D. (2008). U.S. Patent No. 7,375,630. Washington, DC: U.S. Patent and Trademark Office. DiLouie, C. (2008). Lighting controls handbook. Lilburn, GA: Fairmont Press. Fay, J. (2007). Encyclopedia of security management: Techniques & technology (4th ed.). Boston: Butterworth-Heinemann. Fennelly, L. J. (2004). Effective physical security. Amsterdam: Elsevier Butterworth Heinemann. Fielder, W. J., & Jones, F. H. (2005). The lit interior. Oxford: Architectural Press. Garcia, M. L. (2008). The design and evaluation of physical protection systems. Amsterdam: Elsevier/Butterworth-Heinemann. Honey, G. (2007). Intruder alarms. Oxford: Newnes. Kaushik, A. R., & Celler, B. G. (2006, August). Characterization of passive infrared sensors for monitoring occupancy pattern. In Engineering in Medicine and Biology Society, 2006. EMBS'06. 28th Annual International Conference of the IEEE (pp. 5257-5260). IEEE. Kharkovsky, S., & Zoughi, R. (2007). Microwave and millimeter wave nondestructive testing and evaluation-Overview and recent advances. Instrumentation & Measurement Magazine, IEEE, 10(2), 26-38. Landoll, D. J. (2011). The security risk assessment handbook: A complete guide for performing security risk assessments. Boca Raton, FL: CRC Press. Moghavvemi, M., & Seng, L. C. (2004, November). Pyroelectric infrared sensor for intruder detection. In TENCON 2004. 2004 IEEE Region 10 Conference (Vol. 500, pp. 656-659). IEEE. Morawski. (2006). Security Now- A Guide to Electronic Security. lulu.com. Walsh, J. (2003). Asset protection and security management handbook. Boca Raton, FL: Auerbach Publications. Woodhouse, I. H. (2006). Introduction to microwave remote sensing. Boca Raton: Taylor & Francis. Read More

The system has a minimum resolvable temperature that is considered appropriate. Otherwise, a drastic thermal gradient sets out a different milieu energy pattern. Different elements in the environment could create hot spots, thereby interfering with the efficacy of the detection system. For instance, if there is heater in a room installed with a PIR sensor, switching it on could create a rapid temperature changes that could set off a bogus distress call. Also, simple events such as intense sunrays streaming in from a window can use enough temperature difference to trigger a false alarm.

Lastly, this detection system is not animal proof. Insects and pets can easily set off a false distress signal. Vibrations too can set off incorrect alarms. This is because the vibrations can cause thermal sources to seem as interference activities, hence, setting off the distress signal. Also, electromagnetic fields can affect the alarm systems (Moghavvemi & Seng, 2004). Simple gadgets such as hand held radios are capable of causing significant electromagnetic disturbances that could compromise the system.

Additionally, poor housekeeping practices could compromise the system. For instance, sizeable amounts of garments or any other wrapper materials could defeat the sensor. Also persons moving in slow motion can beat the system. The explanation for this type of reaction is that the system’s field view can be distracted. Garcia (2008) notes that simple techniques such as tape masking can distort the detection system’s field of view thereby converting to thwart accurate sensor function. The second type of sensors is the microwave sensor.

According to Woodhouse (2006) microwave sensing technologies interacts well with other radiations. Objects are capable of emitting microwaves; the detection units expose these waves. The sensors detect electromagnetic radiation frequency of about 10GHz. There are different designs of microwave detectors; nonetheless, the working principle remains the same. For instance, monostatic microwaves both a transmitter and receiver and their detection scope is about 400 feet (Landoll, 2011). They offer restricted protection within a given space.

The second design for microwave detection technologies is the bistatic microwave that has an independent transmitter and receiver. It has up to four times the detection scope as the monostatic designs and offers more than localized detection. Microwave sensors applied in motion detection in combination with PIR methods are most likely to have a monostatic design. In this type of configuration, the recognition system is likely to have one antenna that both broadcasts and receives the electromagnetic radiations.

In order to detect intrusion, the system measures the magnitude of Doppler shift. Thus, if there is any movement within the sensor region, the detection unit measures the changes in Doppler frequency and if the aptitude and duration is abnormal then an alarm is set off. The system sends out radiation of known frequency and if there is no intrusion or obstruction then transmission sent back to the receiver is within the expected range of frequencies. However, the proximity to the sensor affects the frequency rates.

Consequently, the system achieves optimum sensitivity when the target object is further away from the sensor compared to when it is closer. Secondly, the shape and design of the antennae affects the efficacy of the system because the detection patterns changes depending on the design (Kharkovsky & Zoughi, 2007). The accurate detection pattern has asymmetrical points at certain regions. Consequently, if an object happens to be within an undetectable region then the system may fail to recognize the intrusion.

Despite the weaknesses, this system is beneficial because microwaves can penetrate surfaces such as walls, hence, offering a wider range of protection. On the other hand, this strength can expose the system to excessive interferences, hence, increasing the chances of false alarms.

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