GEONET Station is the facility that receives signals from GNSS satellites. The information, obtained by signal analisys, coming down from space is also used to understand crustal movement. So you could say, "This is a power spot that connects the vibrations of the universe with the energy of the earth!" Sure I won't, it is too spirtual. :-)
If you see it without any prior knowledge, you might think, "Isn't it emitting strange radio waves? ", "Isn't it collecting undesirable information?" There might be people who are suspicious about it. In order to avoid unnecessary misunderstandings, a nameplate explaining the intentions and history of the project is indispensable.
The explanations vary slightly depending on decades, but one of the most detailed explanations I've seen is for the GEONET Station "Nisshin" (940063), at the Nisshin City Civic Hall, which borders the east side of Nagoya City. The text is deliberately carved into stone and placed at the foot of the pillar, but what is the reason for this level of detail? The possible reasons are as follows, I guess some of them may be right (all of them?).
-- It is located behind the bus stop of a busy civic hall so a detailed explanation was necessary.
-- There were several art and historical objects nearby, so It couldn't afford to defeat.
-- There was an enthusiastic person in charge local office of GSI.
The following is a composite of two photos of the inscription and the text I read. Some words I could not read and some sentences I bolded. Please take a look.
GPS observation station
The Geospatial Information Authority of Japan (GSI) call this stainless steel structure "GPS observation station". The GPS observation station consists of a tower, antenna, receiver, and communication equipment. At the top of the tower, there is an antenna for receiving radio waves from GPS satellites orbiting 20,000 km in the sky. The inside of the tower, receivers and communication equipments are working. At the base of the tower, power supply cables and telephone lines to transmit observation data to the GSI in Tsukuba City, Ibaraki Prefecture.
The GSI calculate and process the data observed at GPS stations around the country to determine the exact location of GPS stations, as well as to determine the expansion and contraction of the land. These results are used as standards for various types of surveying and as basic data for earthquake prediction research.
The term GPS is an abbreviation for "Global Positioning System". GSI has translation it in Japanese, but the abbreviation GPS is used in normal.
GPS is a positioning system developed and operated by the United States to aid in the navigation of ships, aircraft, etc. It is a system that receives radio signals ????? from GPS satellites and calculates the three-dimensional position coordinates of the receiving point in real time worldwide. The positional accuracy of a single observation point is only a few tens of meters, but by conducting simultaneous observations at multiple points, the relative positions of the observation points can be accurately determined.
Geographical Survey Institute, Ministry of Construction
Now, let's read through this text.
In the first paragraph, the outline of the system is described, including materials, structure, and components.
In the second paragraph, it explains how the data obtained will be useful. The term "Calculating the exact location" is used elsewhere, but I feel originality to the expression "stretching and shrinking of the land". The term "earthquake prediction" is no longer in use.
In paragraph 3, it explains the original notation, translation, and abbreviation of GPS. In paragraph 4, after explainings of its main use, to get to the heart of the matter.
In the second sentence of paragraph 4, some letters couldn't be read because blurred, but easy to guess. I think the appropriate word is "broadcast" rather than "transmit". It might convey the nuance that the satellite only sends signals, and the receiver is responsible for positioning calculations.
The last sentence , in bold, expresses the essence of the GEONET. I guess it's useless to build facilities all over the country whose positional accuracy alone is only a few tens of meters. But once multi-points simultaneous observations made, they can determine the position of each points in good accuracy, below centimeter order. In fact, this is why nation-wide CORS network has been developed. This is it, the secret of birth of GEONET!
Visiting many places and gaining more knowledge, I could realize that this is the "core" of the story. Again, I've never seen a very detailed explanation like this, and I wondered how it was made.