DIPOL Weekly Review – TV and SAT TV, CCTV, WLAN

Graphene bolometers for quantum processors.

Physicists from Aalto University and VTT Technical Research Center in Finland have developed a new detector to measure energy quanta with unprecedented speed and accuracy. The detector the team of scientists is working currently on is a bolometer that measures the energy of the incoming radiation, giving feedback on how much it heats the detector.

Measuring qubit energy is at the heart of quantum computers. Most quantum computers now record a quibit energy state by measuring the voltage it induces. However, there are some issues involved in measuring the voltage. Firstly, voltage measurement requires extensive amplification circuits which may reduce the scalability of a quantum computer. Secondly, such circuit uses too much power. Finally, voltage measurements involve quantum noise which brings errors in the reading of the qubit. Quantum computer scientists hope to be able to solve all those problems by using bolometers to measure the qubit energy. The team led by professor Möttönen has developed a bolometer that is fast enough and extremely sensitive, which makes it ideal for this job.

Changing the gold and palladium alloy to graphene resulted in a 100-fold acceleration of the detector while maintaining a low noise level.

The first detector developed by a team of scientists from Finland was a bolometer based on a gold and palladium alloy with an unparalleled low noise level. However, it turned out to be too slow to measure qubits in quantum computers. The breakthrough happened when the detector based on gold and palladium alloy was replaced with the one made of graphene. Graphene has a very low heat capacity which makes it possible to quickly detect very small changes in its energy. The speed of detecting energy differences makes graphene ideal for measuring qubits and other experimental quantum systems. By changing the gold and palladium alloy to graphene, the team has built a bolometer that can take measurements in much below a microsecond, as fast as the technology currently used to measure qubits. Switching to graphene has led to a 100-fold increase of the detector speed while maintaining the same noise level.

HD-TVI cameras in a TV system.

Converting the A/V signal from computers, players or CCTV cameras etc., into high-frequency RF signal used in terrestrial television systems requires the use of a modulator. Such device has one or multiple A/V inputs (RCA, HDMI, etc., depending on the type) and an RF output (commonly known as the antenna output), and it allows you to watch the video and listen to the sound on the selected channel on all TVs connected to the system. For the receiver, the program added to the system is just another terrestrial television channel.

RF modulators can be divided into several groups. The main criterion is the type of signal at the RF output. Analog, which are slowly coming out of common use, and digital DVB-T and DVB-C can be distinguished. Other sub-divisions may be based on the kind and number of inputs and channels, output frequency range, support for HDCP protocol etc.

Incorrect cleaver height as a reason for bad optical fiber cleft.

Proper preparation of the ends of optical fibers is the basis for successful fiber splicing. Even the best and most expensive splicer will not be able to properly connect dirty or improperly cut fibers. For this reason, care for the cleanliness of fiber optic tools is extremely important. A good, clean and well-adjusted fiber optic cleaver guarantees correct and precise cleaving of fibers.

Before proceeding with the adjustment of the cleaver height, it is good to find out whether the blade in the tool is set too high or too low. Of course, it may happen that the installer is not able to determine that during the initial assessment. A good practice then is to deliberately lower or raise the blade to the extreme positions. After reaching one of the extreme positions, gradually lower/raise the blade to set the optimal position. The effect of each change in height should be checked on the splicer display. It is important to do that for two fibers. It may also happen that the fiber looks good on one side and on the other not. It is also important to tighten all stabilizing bolts after changing the height. They also have a slight but still noticeable effect on the blade position.

More tips on how to properly position the blade can be found in the article Cleaving optical fibers without secrets – blade adjustment.

An example of a bad result caused by too high blade position.
The fiber end face is jagged. A characteristic feature of fibers cleft with a blade set too high is damage to the fiber core (in the bright area).

An example of an improper result caused by a little too low blade position.
The fiber is not cleft throughout the entire cross-section (visible a "clove"). The shape and size of the "clove" may of course vary.

Corridor mode in Hikvision cameras.

Most Hikvision IP cameras have the corridor mode which it is particularly useful for monitoring sites with great height in relation to width. It allows to watch a high scene with one camera mounted at a short distance from the area of ​​interest. For example, if the camera image is displayed in the 16:9 aspect ratio, it will be displayed in 9:16 when the corridor mode is enabled. To use this functionality, when installing the camera, rotate it 90° from its normal position.

Basics of IP addressing – part 5.

The previous issue discussed the details of the gateway. Another important parameter is the network port. Network port is a term related to the TCP/IP protocol. They are used on the Internet to distinguish between various services and connections. Protocol ports are marked with integers ranging from 1 to 65535. Some ports (from 1 to 1023) are reserved for standard services, e.g.:

With the port number, it is possible to identify not only the processes, but also well-known services running on distant systems, so it can be considered as a service identifier. For example, if a host is also a web server, it has to open the port 80 when web resources have to be shared with another host.
The DNS will be discussed in detail in the following issue of this Weekly Review.

Nestat – displays active TCP network connections, and ports the computer is listening

Heat maps in stores.

Heat map is a visualization of camera image analysis showing the movement of customers. They show the key parameters for the seller, i.e. where the customers move and how much time they spend at specific shelves. This information can be used to better organize the store space and arrange products on shelves.
The visualization is available in the form of spatial statistics represented by colors applied to the store plan. Red in the image indicates most frequented places and blue corresponds to the areas with the lowest customer occupancy.

An in-store heat map

This function is perfect for supermarkets, discounters and smaller stores. The heat map function is available on the Hikvsion fisheye line 6 and iDS series cameras.

Optical and copper TV/SAT system in a hotel. The designer was given three main objectives to meet. First of all, the system has to cover 5 buildings of a large complex. The system is to distribute the DVB-T signal from a local transmitter and 15 satellite programs in the form of a digital DVB-T signal ...>>>more

Diagram of the optical/copper SMATV system distributing the programming

Reliability and modernity