The expansion of the Internet of Things necessitates an increasing demand for location services. Several institutions forecast that 60% of IoT devices will rely on geographical location data. Specifically, the market for extensive outdoor positioning is one that must not be overlooked.
The world is home to an exclusive club known as the Global Navigation Satellite System (GNSS), which has garnered immense interest from heads of state and the research community. With only four members, namely the American GPS, European GPS (Galileo GALILEO), Russia’s GLONASS, and China’s Beidou COMPASS, this high-end club has captivated the attention of top scientists and engineers worldwide.
China Beidou is an emerging participant, and it stands out as the participant with the most robust growth trajectory. What is the current status of Beidou? How does it influence our daily lives? This subject matter is undeniably captivating. Numerous scholarly publications delve into Beidou, yet these specialized articles often inundate ordinary individuals with technical jargon, rendering them disinterested in perusing such material.
Block GPS signal
With the continuous growth of the GPS locator market, there is a rising demand among individuals who wish to avoid being tracked by GPS signals. Consequently, these individuals are now seeking out products that can effectively block GPS signal tracking, commonly referred to as GPS signal jammers.
The gps jammer has the capability to successfully obstruct the GPS locator. By utilizing a jammer, it disrupts the regular functioning of the GPS locator, resulting in incomplete transmission of data to the locator monitoring platform. Similar to a mobile phone, the GPS locator requires insertion of a mobile phone card or IoT card to transmit data. Therefore, if the GPS signal jammer can impede the signal transmission of the mobile phone card, it can effectively block the GPS locator.
The anti-location jammer is capable of disrupting the GPS locator by emitting radio interference waves within a specific electromagnetic range. This effectively replicates the electromagnetic conditions required to block signals, rendering the GPS signal jammer ineffective and preventing data upload to the platform, thereby rendering the device offline and unusable.The device has the capability to efficiently block positioning signals like GPS, Beidou, and base stations. With a transmission power of 5W, it offers an adjustable effective shielding distance ranging from 1 to 15 meters (pre-set during manufacturing). By effectively blocking the GPS locator within the vehicle space, it ensures non-functionality without posing any harm to the human body.
Start with GPS
The commencement of the space era for humanity occurred on October 4, 1957, when the Soviet Union successfully launched the inaugural artificial earth satellite. This significant event captured the keen interest of the United States. Notably, within Hopkins’s Applied Physics Laboratory, mathematician Bill Guy and physicist George Weifenbach made a remarkable discovery. They observed a phenomenon wherein the frequency of this satellite had undergone a shift, later identified as the Doppler shift effect resulting from relative motion.
Considering the satellite’s orbit options, it is crucial to determine whether a low, medium, or high orbit should be adopted. Opting for a low orbit would result in reduced launch costs and enhanced accuracy. However, it is important to note that if global coverage is desired, a total of 200 satellites would be required.
Theoretically, three satellites can provide global coverage if placed in a high orbit. Nevertheless, the challenge lies not only in launching such satellites but also in the significantly reduced positioning accuracy. This is primarily due to two factors: the excessive altitude of the orbit leading to substantial errors, and the minimal relative speed between the geostationary orbit and ground objects, which hampers the effectiveness of the Doppler frequency shift solution method.
The medium orbit presents a balanced solution, requiring only 24-36 satellites to provide global coverage. Due to the orbital movement, the speed relative to the satellite remains significantly high, enabling the effective utilization of the Doppler frequency shift method, even when the objects on the ground remain stationary.
Taking into account the aforementioned thorough deliberations, the United States made the decision to opt for a constellation of 24 satellites in a medium orbit. The inaugural satellite was successfully launched in 1978, and the complete system became operational in 1995. Presently, there exist 30 satellites, categorized into two distinct positioning modes: military and civilian. This approach remains accessible to the global 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.