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No. 20/2022 (May 16, 2022)
Record-breaking depth of field.
Researchers at the U.S. National Institute of Standards and Technology (NIST) have developed a nanophoton camera with a bifocal lens that has a record-breaking depth of field. The distance range at which the camera can generate sharp, high-resolution images ranges from 3 cm to 1.7 km.The researchers and designers were inspired by the eyes of trilobites, arthropods that inhabited the seas some 530 to 250 million years ago. Their organ of sight was composed of several thousand independent units with their own cornea, lens and light-sensitive cells. Dalmanitina socialis was particularly interesting as it produced lens assemblies with different refractive indices – an upper lens with a central bulge made of calcite and a lower lens made of organic compound. The body could simultaneously focus at extreme distances, allowing it to simultaneously search for food and patrol the waters for predators at distances greater than a kilometer.
Schematic of the Trilobite eyes that inspired the camera.
The upper lens with the central bulge was formed from calcite, the lower lens from an organic compound.
The upper lens with the central bulge was formed from calcite, the lower lens from an organic compound.
The researchers decided to create lenses in the shape of those in which trilobites were equipped. This was possible thanks to the technique of flat lenses called metasurfaces. They consist of millions of tiny pillars (about 600 nm high) made of titanium dioxide. Nanopillars operate at the subwavelength level – they scatter and capture light with great precision, and are therefore able to define the phase, spectrum, polarization and modality of light. This is a fundamental difference compared to standard lenses that use the phenomenon of refraction and propagation of visible light through glass optics. They enable recording of the light intensity, but no longer the direction of incidence.
The nanopillars are arranged perpendicular to the object and the sensor and aligned in such a way that each transmits light through different areas of the lens. At the extremes, some of the incoming light must pass through the longer and some through the shorter side of the pillar. On the longer path, the light passes through more material and is therefore deflected more. The opposite happens on the other wall. The nanopillars deflect the light so that distant objects (1.7 kilometers) as well as nearby objects (a few centimeters) are focused on a single plane. The next step is to use neural network algorithms to correct defects arising at intermediate distances (blur, chromatic aberration). The final image is sharp and free of aberrations over the entire depth-of-field range of several hundred meters.
This state-of-the-art imaging technique is in the early stages of testing, but could be a breakthrough in imaging systems, consumer photography, 3D imaging, optical microscopy, and machine vision systems.
How temperature affects battery operation
The nominal operating temperature of maintenance-free batteries varies and, depending on the model, is usually between 20 and 25°C. Working at other temperatures affects their performance.As the temperature drops, the capacity of the cells decreases, so in winter there are, for example, problems with starting a car engine. However, if the battery is not deeply discharged, low or even freezing temperatures should not damage it. Working at elevated temperatures causes a significant reduction to their service life. This is halved for each sustained increase in temperature of 8°C above the rated value. This means that, for example, a battery with a rated temperature of 25°C operated at 33°C will retain 50%, and at 41°C only 25% of the projected lifetime.
Emu battery with AGM (Absorbent Glass Mat) technology.
The dark elements are lead plates, while the light ones are glass - fiber layers soaked in electrolyte.
The dark elements are lead plates, while the light ones are glass - fiber layers soaked in electrolyte.
To achieve the maximum service life of a buffer battery:
- install the battery away from devices being heat sources (e.g. transformer, heat sink),
- keep at least 1.5 cm space around the battery and use devices with ventilation openings to ensure free air circulation,
- use effective, natural or forced ventilation or air conditioning,
- use a charging circuit with temperature compensation for the charging voltage if the operating temperature is supposed to exceed 25°C.
Configuring TERRA digital modulators with mobile devices.
TERRA MHD001P R86103 and MHD002P digital modulators R86104 can be configured via the Google Chrome web browser (for Android and Windows) and WebBLE GreenParkSoftware application (for iOS). Pairing and establishing communication between devices (smartphone, tablet, laptop) and the modulator is wireless via Bluetooth. To enable Bluetooth wireless communication of the modulators hold the "+" and "-" buttons simultaneously pressed on plugging in to the 230 VAC wall outlet, until the green LED starts blinking. Then run the Google Chrome browser and enter the address: mhd.mydtv.live. TERRA modulators can also be configured in the standard way using "+" and "-" buttons and the display located under the cover which is part of the enclosure.
Simple and intuitive, the configuration allows users to quickly set up all the required parameters
Digital HDMI-->DVB-T modulators are ideal for systems where the content from one or two sources is supplied to multiple TV sets. This is the case, for example, in hotel systems equipped with older TV sets that cannot receive DVB-T2/HEVC signal.
Batch time synchronization in Hikvision devices.
The iVMS-4200 application allows batch synchronization in all devices that have been added to the application. Incorrect time setting can cause many problems. In the case of CCTV systems, it can make it difficult to determine the exact time of an incident, and in the case of video door entry systems it can cause problems with correct operation of tags according to a schedule. Synchronization can be done in a number of ways, such as when adding to an app or when directly logging into a device. For a batch update the time in iVMS-4200, after adding devices, go to: Menu -> Tool -> Batch Time Sync.
Batch time synchronization for Hikvision devices using iVMS-4200
Fiber optic distribution frames in multi-family buildings – cabling in blocks of flats?
In the case of FTTH networks in multi-family buildings, the prevailing concept is to provide each apartment with a separate fiber optic cable, which starts in the telecommunications/server room. Such an approach has its advantages, the first of which is its simplicity – the subscriber cables are laid in parallel with other multimedia cables (copper coaxial cables and twisted pairs) in a star topology. Splicing is only done on the fiber ends and takes place in the apartments and technical room.An alternative to the above solution is the fiber optic topology based on the use of multifiber trunk cable, couplers/intermediate boxes and subscriber cables on the sections leading directly to the apartments. The advantages of such a solution include primarily:
- significantly faster and easier fiber splicing in the technical room due to a reduced number of cables (the same number of fibers, but less cables means faster splicing),
- dividing the network into segments eliminates the problem of large numbers of cables entering/leaving the main cabinet – easier to deploy, much less space required in shafts,
- price – one 24J cable is cheaper than twelve 2J cables,
- possibility to use prefabricated cables with connectors because of dividing cable routes into shorter sections.
Location of fiber optic boxes in a building – the concept of multifiber optic buses
The disadvantage of this approach is, if factory terminated cables are not used, the need for additional intermediate splices in the floor boxes.
Transmission of HDMI and USB signals in fiber optic cables.
Whenever the DVR viewing and control is to be carried out from a remote room (e.g. surveillance center), there is a need to transmit HDMI and USB signals. If the cable distance does not exceed 100 m the H3613 converters can be used and connected with a standard twisted-pair cable cat. 5e.If the distance exceeds 100 m, the user should use an active device, e.g. the N29915 switch, to extend the signal by another 100 m. However, in the case of such connections it is better to use fiber optic cable. The maximum fiber optic cable length depends on the media converters used and can be up to 40 km in case of Ultimode L10025 media converters.
Application diagram of fiber optic media converters with HDMI + USB converters
 | Horizontal straight-through joint GFP2FS for DAC cable L56040 is designed for two cables with outer diameter not exceeding 6.5 mm. Due to its small size it is an excellent solution for FTTH network cabling. It is the joint of choice in case of repair of DAC cables. It can be used directly in the ground, in wells, cable ducts, cable trays and also in outdoor cabling. The joint has mounting holes to allow installation on flat surfaces. | |
 | Channel amplifier: WWK Alpha+ Telmor R89864 is designed for SMATV antenna systems for receiving DVB-T/T2 digital terrestrial television in multi-family buildings, residences, hotels, boarding houses, holiday homes, schools, hospitals, etc. The amplifier is dedicated to difficult reception conditions with signals of various levels, transmitted from several directions. | |
 | The optical kit SAT/RTV OTX 1310 KIT TRIAX A9860 is used for installation with fiber optic technology. Using the kit you can create systems that enable transmission of satellite SAT, terrestrial DVB-T2 and FM/DAB radio signals. This technology is distinguished by low attenuation, low interference, and, most importantly, allows to transmit signals over long distances. | |
Worth reading
How to disarm NVR using an alarm input? If the building has other systems besides the surveillance system, e.g. intelligent building system, access control system, or alarm system, it is worth considering the implementation of the DVR disarming function. When activated, it disables notifications that are generated by alarm events (motion detection, crossing the virtual line, etc.). The incidents are normally recorded in the system, the record is kept, but it is possible to disable alarm actions, such as: sound warning, sending e-mail messages, activation of alarm output or sending notifications to the client application...>>>more
How to connect the signal from the Satel Integra 32 control panel to an alarm input of the DVR, using a relay
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