ネタ | Cell phone jammers block some nasty signals道場 | ホビー・ゲーム | まにあ道

The evolution of the Internet of Things demands an increasing reliance on location services. Projections from various organizations indicate that a substantial 60% of IoT devices will utilize geographical location data. Notably, the market for large-scale outdoor positioning is poised for significant growth.

The world is witness to an exclusive club known as the Global Navigation Satellite System (GNSS), which stands as a pinnacle of navigation technology. Despite its limited membership, consisting of only four members, this club has managed to attract the attention of heads of state and has become a subject of extensive research for numerous top scientists and engineers.

The distinguished members of this club include the American GPS, European GPS (Galileo GALILEO), Russia's GLONASS, and China's Beidou COMPASS.Beidou, the newest participant hailing from China, has gained substantial momentum in its development. What is the latest update on Beidou? How does it impact our daily routines? This intriguing subject matter has sparked widespread interest. However, academic journals often inundate readers with technical terms, making it unappealing for the general public.

As the GPS locator market continues to thrive, there is a noticeable trend among certain individuals who wish to avoid being tracked through GPS signals. This has resulted in a surge in the demand for GPS signal jammers, which are products designed to block GPS signal tracking.

By utilizing a gps jammer , the GPS locator can be efficiently blocked. The jammer interferes with the normal functioning of the GPS locator, causing incomplete transmission of data to the locator monitoring platform. Similar to a mobile phone, the GPS locator needs to have a mobile phone card or IoT card inserted in order to transmit data. Therefore, if the GPS signal jammer can obstruct the signal transmission of the mobile phone card, it can effectively block the GPS locator.

Through the emission of radio interference waves, the anti-location jammer has the ability to disable the GPS locator within a designated electromagnetic range. This creates an electromagnetic environment similar to that of the signal-blocking device, effectively blocking GPS satellite signals. Consequently, data upload to the platform is hindered, rendering the device offline and incapable of normal operation.With the capability to effectively shield positioning signals such as GPS, Beidou, and base stations, this device is highly reliable. It operates at a transmission power of 5W and provides an adjustable effective shielding distance of 1 to 15 meters (pre-determined at the factory). By completely blocking the GPS locator within the vehicle space, it ensures non-operation without any adverse effects on human well-being.

On October 4, 1957, the Soviet Union's launch of the world's first artificial earth satellite marked the beginning of the space century for mankind. The United States closely monitored this development. Notably, mathematician Bill Guy and physicist George Weifenbach made a discovery at Hopkins's Applied Physics Laboratory. They identified a phenomenon wherein the frequency of this satellite had shifted, which was later determined to be the Doppler shift effect caused by relative motion.

The satellite's orbit selection is a critical consideration: low, medium, or high. If a low orbit is chosen, the launch cost will be reduced and accuracy will be enhanced. Nevertheless, it is important to bear in mind that global coverage would necessitate the deployment of 200 satellites.

In theory, the world can be covered by three satellites if placed in a high orbit. However, the challenges associated with launching high-orbit satellites are not the only concern. The more significant issue is the compromised positioning accuracy. This can be attributed to two reasons: firstly, the high altitude of the orbit leads to substantial errors, and secondly, the minimal relative speed between the geostationary orbit and ground objects makes it impractical to utilize the Doppler frequency shift solution method effectively.

Choosing a medium orbit provides a balanced solution, requiring only 24-36 satellites to cover the entire world. The considerable speed difference between the satellite and stationary objects on the ground facilitates the optimal utilization of the Doppler frequency shift method.

Considering the comprehensive factors outlined above, the United States opted for a medium-orbit constellation consisting of 24 satellites. The first satellite was launched in 1978, and the entire system became operational in 1995. Currently, there are 30 satellites, which are divided into two positioning modes: military and civilian. This approach is open to the international community.

Beidou generation criticized

After the loss of MH370, a lot of popular science appeared, making the public familiar with the term Doppler effect. Is the Doppler effect a good thing or a bad thing for satellites? It depends on what kind of satellite it is. This is a good thing for navigation and positioning satellites, because the greater the relative speed of the satellite relative to the measured object on the ground, the more obvious the Doppler effect, and the positioning will be more accurate. This is even the core principle basis for positioning navigation satellites.

However, the Doppler effect is a bad thing for communication satellites, because the frequency offset will cause communication failure and must be corrected. For example, the Asia-Pacific International Communications Satellite located over the Indian Ocean is fixed relative to the ground. The seven search signals sent by the missing MH370 in the final stage were measured by this satellite and found a frequency offset. This was originally data that was to be corrected, but it was not Thinking of this, it became the only evidence to speculate on the aircraft's trajectory. To sum it up in one sentence: Using communication satellites to position satellites has turned the Doppler effect, which was originally a bad thing, into a good thing.

The scale of Beidou II is similar to that of GPS, and the applied orbit and frequency are relatively consistent with those of European Galileo. This inevitably encounters the problem of competition for satellite orbits and frequencies. Satellite orbits and space frequencies are resources shared by mankind, so how should they be distributed? International rules do not divide them by country or population, but whoever takes advantage first will get it.

In 2005, the first satellite of the Galileo project was launched, but it was not activated. It only occupied the orbit but not the frequency. Why was it not activated? The reason was that there was no money, and activation required money, and Europe was a little tight on money. The first star of China's Beidou II generation also went up to the sky, and it was opened as soon as it went up. Now the orbit and frequency are occupied.

Galileo in Europe was tinkering slowly, while Beidou in China kept launching satellites one after another, and later even built a double satellite. Some frequencies of the Galileo project and Beidou II overlap, and both sides are in the field of international telecommunications. The alliance has been registered, and whoever gets it first will get it. China's fast pace has made Europe anxious, and it has put pressure on China through the United States, asking China to slow down and wait for the European people.