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DIPOL Weekly Review - TV and SAT TV, CCTV, WLAN
No. 12/2020 (March 23, 2020)
Neural hardware for faster image recognition. Scientists from the Technical University of Vienna (Technische Universität Wien, TUW) have developed an electronic system capable of object recognition, consisting of an image sensor, whose "pixels" are interconnected in a neural network. The parameters (connections) of the network can be modified and thus trained to recognize specific objects. This represents a new approach to image recognition, as such systems have thus far been built in the form of computer software. This time, the data is not analyzed by a computer but a specialized system that takes nanoseconds to provide information on what it can see at any moment.
The system was developed and manufactured at TU Vienna. It is based on photodetectors made of tungsten diselenide, an ultrathin material composed of only three atomic layers. The individual photodetectors, or the "pixels" of the camera system, are connected with the other layers of elements that make up the neural network. The electrical parameters of each connection can be modified to regulate its sensitivity and thus influence the result of image analysis. This can be done remotely through a computer. The scientists give an example of letter recognition, where users should regulate the sensitivity of individual connections step by step until each letter reliably generates a corresponding output signal. This is how the neural network is configured: some connections are strengthened, others weakened. Once the learning process is over, the computer will no longer be needed; the network will now work alone. If a given letter is presented to the sensor, it will generate the output signal within 50 nanoseconds, corresponding to the numerical code of the letter the system has just recognized.
The resolution of the system is low, but can be scaled up. In theory, it can be configured to distinguish between different objects (e.g. apples and bananas), but will be particularly useful in scientific experiments and other specialized applications, where extremely high speeds are required. It can be used to study short physical phenomena, e.g. cracking, or to detect which of several possible particles has just passed by.
Fever-screening cameras. In response to the current coronavirus threat, Hikvision has prepared a number of solutions that use thermal cameras to carry out precise temperature measurements in the 30° - 45°C range, with up to 0.5°C or 0.3°C accuracy (using a blackbody calibrator):
  • DS-2TD2636B/P
  • DS-2TD2617B/PA
  • DS-2TD1217B/PA
  • DS-2TP21B-6AVF/W/P
The cameras form part of Hikvision's design series, which means that customers will only get a price quote and the opportunity to purchase the device when a design is submitted to a distributor of Hikvision products.
The models listed above take one second to automatically detect individuals who suffer from a fever and show symptoms of infection. The cameras can be used wherever such measurements may be necessary to ensure safety, e.g. at entrances to companies, stores, etc.
All bodies with temperatures above absolute zero (0 K = -273.15 °C) emit infrared radiation. Based on the relationship that exists between radiation intensity and temperature, a thermal camera that picks up infrared rays is able to use their wavelengths to calculate the temperature of an object. The devices allow users to see the distribution of temperatures on the surface of a given body and meausre their values.
Calibrating optical power meters - certificates. Not unlike most instruments, optical power meters perform measurements with a certain degree of uncertainty, the value of which is usually specified in the product data sheet and confirmed by an attached certificate.
In the case of most cheaper optical meters, the certificate has no formal power and represents a mere declaration concerning the final quality of the product. The document is issued by the manufacturer, who is also the party responsible for the process of measurement and calibration. The latter is not required to conform to any specific standards and the calibration instruments used do not need to have the status of reference devices. In many cases, however, such a basic certificate is sufficient to confirm that the measurements will be reliable.
A basic calibration certificate issued by an optical power meter producer
Installers who require a higher-level certificate should choose products compliant with the ISO9001 and IEC17025 standards. In this case, relevant certificates can only be issued by producers who follow procedures specified in the ISO9001 quality management standard, or, better yet, by an external lab that has implemented the IEC 17025 guidelines.
The highest level of certification is offered by an accredited lab. Several dozen IEC 17025 accredited labs around the world perform calibration based on rigorous procedures defined in the European IEC 61365 standard or an American equivalent, i.e. TIA-455-221/FOTP-231. Meters with such certificates are top-quality devices, which, provided that full compliance with relevant standards is ensured, can serve as a reference device for the calibration of other instruments.
The two best known labs used by renowned measuring equipment producers are the American N.I.S.T (National Institute of Standard and Technology) and the Australian NMI (National Measurement Institute). In Poland, calibration can be performed at the LMEEiO (Laboratory of Electrical, Electronic, and Optoelectronic Metrology) in Warsaw. The institution is accredited by the Polish Center for Accreditation (PCA) and can calibrate any optical power meter.
It is worth noting that even if the device you have purchased does not come with a certificate issued by an accredited lab, you can independently request its calibration at an institution of this kind. The service is paid; a fee is charged for each wavelength included in the procedure. The lab, however, only performs calibration, without any adjustment. Thus, users are informed that their meter will show a specific deviation from the reference device. This deviation should be taken into consideration during every measurement, unless the meter has a manual calibration option. In this case, any errors identified in the lab can be corrected. A device thus calibrated can then be used to perform measurements of any kind and create measurement records.
Optical Power Meter: TM503N
The TM503N L5816 meter can be calibrated manually, which, together with calibration at an accredited lab, ensures the highest measurement accuracy (the lowest uncertainty).
Amplifying DVB-T signals in large shared systems. In large shared terrestrial TV systems used in multi-family buildings, hotels, and public buildings with several dozen or more outlets, broadband amplifiers should be avoided and instead replaced with channel amplifiers that allow to equalize signal levels in all channels.
Twin Channel Amplifier: Terra at420 (UHF, analog TV & DVB-T, AGC)
View of the Terra at440 R82511 four-channel amplifier
Terra amplifiers are highly selective:
40 dB attenuation just 2 MHz outside the channel boundary
The greatest advantage of the device is its ultraselctive SAW (Surface Acoustic Wave) filter. The image above shows the amplification of one channel and the selective signal weakening in neighboring channels. TERRA's at440 amplifiers (R82511) are ideal for systems that distribute signals over neighboring channels.
The same image in several receivers. Signal HD HDMI-to-IP converters enable users to connect a source of HD content to an HD-enabled television/monitor, using a CAT5e/6 twisted pair cable. The set includes transmitter and receiver units.
The IP signal from the transmitter may be applied to an Ethernet switch and split among multiple receivers. The bit rate of the compressed signal at the output of the transmitter equals about 15 Mbps. The output signal can only be decoded by a dedicated receiver; this cannot be achieved with a PC equipped with a network card. The signal is transmitted over a multicast connection (a c. 15 Mbps stream).
An application of the H3613 HDMI > IP converter/extender set and additional two H3613R receivers (point-to-multipoint configuration with an Ethernet switch)
Emergency power supply in a PoC system PoC, or Power over Coaxial, is a system of allowing for the transmission of power supply via the video coaxial cable. As the cabling carries power along with the video signals, the installation of the system is considerably simpler - each camera is connected with the system via a single coax or a twisted pair of wires from a minimum cat. 5e cable.
HD-TVI TURBO HD 4.0 DVR: Hikvision DS-7204HQHI-K1/P (4ch, 1080p@15fps, H.265, HDMI, VGA, PoC) HD-TVI Turbo HD 3.0 Camera: Hikvision DS-2CE56D0T-VPIR3E (ceiling, 1080p, 2.8-12mm, 0.01 lx, IR up to 40m) HD-TVI TURBO HD 4.0 Camera: Hikvision DS-2CE16D0T-VFIR3E (compact, 1080p, 2.8-12 mm, 0.01 lx, PoC, IR up 40m)HD-TVI TURBO HD 4.0 Camera: Hikvision DS-2CE16D8T-ITE (compact, 1080p, 2.8 mm, PoC, 0.005 lx, IR up to 20m)21.5UPS CyberPower UT850EG(FR)
A CCTV system with PoC emergency power supply
The implementation of emergency power supply is also simplified; in the event of a power outage, a UPS will ensure supply to the monitor and the cameras. In such situations, th built-in battery of the UPS will keep all the connected devices working for some time. The average backup time depends on the UPS model (battery capacity) and power consumption. For example, the CyberPower UT850E-FR N9723 UPS can supply power for about 20 minutes at a load of 90 W and for about 30 minutes at a load of 60 W.
New products offered by DIPOL
Keystone F/IEC Module: LogiLink NK0020
Keystone F/IEC Module: LogiLink NK0020 J2311 allows to connect two coaxial cables terminated with F and IEC plugs. The modules can be directly placed in patch panels and outlets compliant with the Keystone standard.

Ceiling IP Camera: Hikvision DS-2CD2347G1-L (4MP, 2.8mm, 0.0014 lx, white light up to 30m, WDR, H.265, ColorVu)
Ceiling IP Camera: Hikvision DS-2CD2347G1-L K00311 is an ideal solution for all those who wish to expand their CCTV systems to include a camera that allows to monitor the scene in the color mode around the clock and thus detect all the necessary details. The camera has been fitted with a 4 MP 1/1.8" Progressive Scan CMOS sensor manufactured in the BSI (Backside Illumination) technology, which stands out for its ultra high sensitivity and ability to capture the image even in very low-light conditions.
Fiber-optic Cable: Fibertechnic DAC Z-XOTKtcdD 12J (12x9/125 ITU-T G.652D)
Fiber-optic Cable: Fibertechnic DAC Z-XOTKtcdD 12J L79212 is designed for installataion directly in the ground. It has a HDPE sheath with high crush resistance (4000 N), which also makes it resistant to low temperatures. It can be employed on the last mile of a FTTH system, as well as in any installation that requires terrestrial cables, where casing pipes cannot be used for additional protection.
Worth reading
The best TV for DVB-T2? A change in terrestrial TV broadcasts has been underway in Europe: the current DVB-T system is being gradually phased out and replaced with a more effective standard, DVB-T2, based on HEVC video compression (also known as H.265 and MPEG-H Part 2). In order to receive DVB-T2 channels, TV devices must be able to decode the new video compression format...>>>more
When buying a new TV, make sure it supports the DVB-T2 standard and the HEVC codec (also known as H.265 or MPEG-H Part 2).
Fiber optic cables guide
Fiber-optic cables guide
 
George Popescu
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