When discussing high-tech activities such as space navigation and interstellar exploration, (Galaxy Positioning System, referred to as GPS for short, no, this is the galaxy level, and it must be distinguished from the one on the earth~) is a key technical support system that cannot be avoided! It is like driving and navigation on Earth, but its scope of action has expanded to the vast and boundless Milky Way, and even further galaxy space… Its core and fundamental function, in short, is to help spacecraft, detectors, and even interstellar shuttles that may appear in the future, accurately know their momentary position information in the huge galaxy, and can assist them to plan the most reasonable and energy-saving routes, and finally safely arrive at the distant, pre-set destination planet or space station. The system is not built casually. It requires a lot of precise and complex satellites – which should be called space beacon satellites or navigation reference satellites – deployed at different key locations in the galaxy. These satellites are like conscientious cosmic beacons, constantly sending radio waves containing their own precise coordinate data and accurate time signals to all directions. After receiving signals from at least four satellites at different locations, a series of complex and troublesome calculations are carried on the spacecraft, such as measuring the tiny time difference between the signal being transmitted from the satellite to being received, and taking into account the characteristics of the speed of light propagation in the universe and various possible gravitational field interference factors, etc., you can in turn calculate the coordinates of the three-dimensional space where you are currently in. Isn’t it amazing?
1. Satellite Constellation Construction Module : This is the "skeleton" part of the entire Galaxy Positioning System. Without it, everything is free from discussion. First of all, you need to carefully select and reasonably distribute the navigation satellites within the galaxy, which require hundreds or thousands of navigation satellites, with specific requirements on galaxy size and navigation accuracy. The orbital design of these satellites is also super exquisite and cannot be distributed in a mess. It is necessary to ensure that any possible navigation area in the galaxy can receive stable signals from four navigation satellites at the same time. This is a basic prerequisite for realizing positioning! Some satellites may operate in vast deep space orbits far away from other celestial bodies and relatively stable gravitational environments, and are mainly responsible for providing large-scale, basic framework positioning reference standards; while some satellites may be deployed in some galaxies with relatively large passenger flow and frequent spacecraft activities, so as to improve the location signal coverage density and positioning accuracy level of the region. Provide global procurement services for weak current intelligent products!
2. Signal transmission and coding specification module : The universe and space environment are too complex. Interstellar dust, gravitational magnetic field interference, and various Wave (electromagnetic wave) background noise from distant stars may have adverse effects on the normal transmission of navigation signals. Therefore, signals used for galaxy navigation must adopt very advanced and reliable encoding methods at the beginning of design. Just like when we write a letter, we need to write the words clearly and use languages that others can understand, this encoding not only contains the satellite's own accurate space-time location information—for example, timestamps that are accurate to nanoseconds or even higher, as well as detailed three-dimensional coordinate parameters represented by a certain galaxy coordinate system, but also has strong anti-interference ability, that is, we are not afraid of being "polluted" and messed up by those cosmic noises, ensuring that the signal can still maintain a relatively high clarity and integrity after transmission at a very long distance, so that the receiving instruments on the spacecraft can be interpreted smoothly and accurately.
3. Data processing and positioning solution module : This part is like the "brain" center of the entire system! After the spacecraft receives a pile of raw signal data from different satellites, it cannot be used directly. It must be carried out through a ship-based computer or a special data processing unit for complex decoding, screening and calculation work. This is not a simple addition, subtraction, multiplication and division. It involves correction of the relativistic effect – because in high-speed motion and strong gravitational field environments, some wonderful distortions will occur in time and space. If not corrected, there will be no accurate results; there is also dynamic compensation for slight deviations in satellite orbits; and various delay effects that may occur on the propagation path of signals, such as the comprehensive consideration of factors such as the slight "slow down" by interstellar gases. By using complex astrological algorithms that seem difficult to understand and cannot be understood by ordinary people – no, it is a high-tech positioning algorithm, and finally calculate the precise position, flight speed and current time information of the spacecraft at the current moment under the selected galaxy coordinate system.
When using the Galaxy Positioning System, you may have some common confusions and questions. I will try to answer them below:
Q: If a navigation satellite has a small number of temporary failure problems, such as a few satellites suddenly stop working, will the entire Galaxy positioning system be paralyzed immediately and lose its positioning ability?
Answer: Generally speaking, this situation will not happen! In order to ensure the overall reliability and continuous operation capability of the system, Galaxy Positioning System will introduce multiple backup mechanisms and failure redundant design solutions when designing. When certain satellites cannot provide services normally due to some unexpected situations, the system will automatically and in real time switch to other satellite signals in normal working conditions; and the control center will quickly start the backup satellite launch plan, or mobilize redundant satellites in backup orbit to replace those failed satellites, so short and small number of satellite failures usually do not have too large impact on the continuous stability of the entire system.
Comparing the Earth GPS we use on a daily basis, the difference between them is not a little small
Coverage: Earth GPS can only serve the very limited near-Earth space area around the earth and its surroundings; while the Galaxy Positioning System is facing the entire huge galaxy scale, and the gap in service scope is simply a world of difference. One is "community express delivery" and the other is "global – no – free shipping for all galaxies"!
Accuracy requirements: The positioning on the earth, the accuracy of meter-level and centimeter-level accuracy is sufficient to meet daily applications in many scenarios; but at the galaxy scale, distance is measured by the difference between light years and seconds, so although the requirements for positioning accuracy may not be as "fine" as that on the earth in relative numerical values as on the earth, the absolute error must be controlled within a reassuring range that does not affect the safety of interstellar navigation, and the technical challenges behind this are also completely different levels.
4. Standard module of the coordinate reference system : We earthlings use latitude and longitude to represent location, so what should we use in the vast Milky Way? This requires a unified coordinate reference system standard that is recognized and followed by all civilizations or organizations in the entire galaxy! The establishment of this coordinate reference system usually selects some remote celestial bodies in the entire galaxy that are relatively fixed, have very stable brightness, and can be accurately observed – such as certain types of Cepheid variable stars, or the stable locations where some supermassive black holes are located, etc., as the most basic and fundamental positioning reference points. All the orbital parameters of navigation satellites and the positioning results obtained by the spacecraft will eventually be converted into this unified coordinate system for representation and mutual transmission, so as to ensure that the position information between different spacecraft and different galaxy sites can be recognized and understood, and there will be no chaotic situation of talking with each other.
5. Time synchronization maintenance module : Doing positioning in a space of such a large scale in the universe. If time is not synchronized, then the trouble will be huge, and the positioning result will be errored to 100,800 miles away! Therefore, all navigation satellites in the system must maintain a height and accurate time synchronization state. This synchronization work is not done once and for all, everything will be fine. The ground – no, it should be called the galaxy control center, which will continuously and continuously closely monitor and adjust the clock of each satellite. Considering that the gravitational field strengths in various regions in the galaxy are different and the satellites operate very quickly, according to Einstein's theory of relativity, these factors will cause a tiny but must not be ignored time expansion effect. Therefore, scientists at the Control Center need to conduct extremely precise forward-looking prediction and compensation correction of satellite clocks based on these complex cosmic environmental factors to ensure that all time signals are as uniform as well as trained soldiers!
I personally think that R&D and successful deployment are not just a great and amazing scientific and technological achievement, but also an indispensable "infrastructure"-like key support for a series of grand blueprints such as realizing large-scale interstellar exploration, promoting exchanges between different planetary civilizations, and carrying out intergalactic resource development and cooperation! It has made the originally vast and disorienting deep space of the universe become as clear as our city blocks, illuminating the way forward for brave universe explorers and leading to the unknown and hopeful sea of stars.
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