Chapter Thirty-One Technical Support

  People often regard the image of a ventriloquist's dummy named Stooky, scanned by John Logie Baird in London on October 2, 1925, as the first television picture. He is also called the father of television.

  However, this view is controversial.

  Also in that year, American inventor Philo Farnsworth demonstrated his television system to his boss at Westinghouse.

  Although identical in time, John Logie Baird and Vladimir Zworykin's television systems were very different.

  Historically John Logie Baird's system was referred to as mechanical television, while Semyon Tsvetkov's system was referred to as electronic television.

  The main difference is due to the different transmission and reception principles. The development of television was complex and involved many inventors working on similar ideas at around the same time.

  The United States introduced the world's first black and white television in 1939, set a national color TV standard by 1953, and introduced color TVs in 1954.

  In 1951, American H. - Lo invented the three-gun shadow mask color CRT, and Lo Renqi invented the single-gun color CRT.

  In 1954, Texas Instruments developed the first all-transistor television receiver.

  At the same time that the Soviet Union successfully launched its first artificial satellite, Johns Hopkins University demonstrated that the Doppler shift of radio signals from an artificial satellite could be used to determine the parameters of a satellite's orbit.

  Although this is only a small advance logically, if we can get the satellite running track parameters, then we can calculate the location on earth.

  The concept of satellite navigation can be traced back to 1957, when the Soviet Union launched Sputnik, the first artificial satellite in human history.

  A precise electronic navigation system was successfully developed by the Massachusetts Institute of Technology Radiation Laboratory during World War II. It is a navigation system that uses radio waves with wavelengths and arrival times to calculate its location using triangulation methods.

  Although this device may have an error of over a kilometer, it was the most reliable navigation device for most aircraft and ships before the GPS global positioning system appeared.

  Beginning in 1960, the United States and Soviet Union began researching ways to use military satellites for navigation purposes, with most systems being developed for individual needs of either the Air Force or Navy.

  By 1961, the military had integrated all previous efforts into a single system, known as NAVSTAR. The Soviet Union also began development of a similar system called GLONASS, which was to begin commercial operation.

  All commercial operation of the NAVSTAR system was turned over to the U.S. Department of Transportation, specifically the U.S. Coast Guard, becoming part of the National Navigation Information Service.

  The physical basis theory of the GPS system proposed by Lan Weiming is not as profound as imagined. The basic assumption is that the person launching the satellite can always track the position of the satellite, and then the satellite can directly transmit this data to you.

  Satellites continuously transmit orbiting data and precise time data generated by the atomic clocks they carry. GPS receivers have a dedicated receiver for receiving wireless signals, and also have their own clock.

  When the receiver receives a signal from a satellite, it can be converted into location data through an internal microprocessor, that is to say, it can know how far this satellite is from us and where its direction is, but this position may be at some point on a large arc of the Earth's surface.

  When there are two satellite signals, the receiver calculates a location that is only a circular range formed by the intersection of two spherical signals. When this circular range reaches the surface of the Earth, there will be two intersections, so it can still only get a rough position.

  The third satellite signal will produce two intersection points in the three spherical signals, one of which will reach the surface of the Earth and the other point is on the other side of the satellite in space. Of course, GPS assumes that you are not at that point in space.

  When GPS continuously receives signals from 5 to 6 satellites or more, it can obtain more accurate positioning data. Each satellite produces a different spherical signal, and the receiver automatically calculates the common intersection point of all spherical signals.

  Because each satellite signal emitted is different, and sometimes even lost signals, the average value is used to improve accuracy.

  Receiving signals from more than three satellites allows us to know where we are, and by measuring the time delay between when a signal was sent and when it was received, we can determine if the satellite is still continuously sending signals. Therefore, a GPS receiver must be able to calculate its vertical position in three-dimensional space.

  Of course, not all countries recommend pilots to adopt GPS altitude data, at most it can only be used as a reference, because the accuracy of altitude depends on the frequency of individual satellites, and the altitude error is about two to three times that of horizontal error.

  For example, research institutions have tested ground elevations of about 30 meters, but the values sometimes appear as -60 meters.

  This situation is actually no concern for people driving boats, as they can only travel on a horizontal plane.

  But it is fatal for pilots.

  NAVSTAR consists of three parts.

  The first part is space, with 24 positioning satellites operating in six orbits at an altitude of 20,200 km and a speed of one revolution around the Earth every 12 hours. This ensures that each satellite passes over the same point on the Earth's surface at the same time every day, resulting in there always being 5-8 positioning satellites passing overhead anywhere on the Earth's surface.

  For commercial considerations, most GPS satellite receivers are designed to track as many satellites as possible, but in fact, only four satellites can achieve the positioning effect.

  Each satellite has a lifespan of about seven and a half years. After this period, the orbit will shift and power will gradually be depleted.

  Each country capable of launching satellites has also made preparations in this regard, and three spare satellites are often kept in orbit. When a satellite suddenly fails, they can be used for emergency allocation.

  Secondly, it is composed of five monitoring centers located around the world, three ground antennas and main control stations located at air bases in various countries.

  Surveillance centers around the world are only passively tracking satellites and accumulating range data, which is then transmitted to the main control station. After updating and correcting navigation data there, it is transmitted to each satellite via ground antennas.

  The last part is the part consisting of GPS satellite receivers and users.

  September 12, 1958: Under the leadership of the founder of INTEL Corporation, the integrated circuit was invented and soon followed by the microprocessor.

  Computers designed from 1959 through 1963 are generally referred to as second-generation computers.

  Due to the extensive use of transistors and printed circuits, computers continued to shrink in size and increase in functionality, running FORTRAN and COBOL, and accepting English character commands. A large number of application software emerged.

  In 1960, the first structured programming language was introduced.

  In 1961, IBM introduced the APL programming language.

  In 1963, DEC introduced the first minicomputer.

  Computers built after 1963 are generally referred to as third-generation computers and used integrated circuits.

  This originated in military electronic devices during World War II and was widely used.

  In 1953, double-sided boards appeared and used electroplating processes to connect the circuits on both sides, with holes metallized.

  In 1960, multilayer boards appeared and later flexible circuit boards using polyimide.

  This led to the development of multi-layer printed circuit boards and integrated circuits, which in turn enabled the creation of high-performance electronic computers.

  On this basis, since 1957, Nanyang Federation began to build the automated command system of the military and continuously upgraded it.

  It generally consists of the following subsystems: information collection subsystem, information transmission subsystem, information processing subsystem, information display subsystem, decision control subsystem and execution subsystem.

  These subsystems are organically combined to form a unified whole.

  Information Collection System

  It consists of various reconnaissance devices configured on the ground, at sea, in the air and in outer space, such as reconnaissance satellites, reconnaissance aircraft, radar, sonar, optical cameras, remote sensors and other reconnaissance and detection equipment. It can collect information about the deployment of enemy forces, combat operations and battlefield terrain, weather conditions, etc.

  Information dissemination system

  It mainly consists of terminal, exchange, line and user equipment. The main channel terminal equipment includes wired electrical wave communication, microwave relay communication, scatter communication, satellite communication and optical communication equipment; the main switching equipment includes telephone, telegraph, data switch and so on.

  These devices are often combined into communication networks with multiple functions, rapidly and accurately transmitting various types of information in a confidential and uninterrupted manner.

  Information Processing Subsystem

  Composed of computer hardware and software.

  Information processing is the process of taking information input into a computer, through various software compiled according to predetermined goals, and performing comprehensive processing, classification, storage, retrieval, calculation, etc., and can assist commanders in formulating battle plans, simulating, comparing, and optimizing various plans.

  Commonly used military information processing includes document processing, data processing, intelligence retrieval, graphics processing, and image processing.

  Information Display Subsystem

  Composed of various devices that output visual information.

  Display devices are typically divided into two types: single-user display terminals and large-screen displays for commanders.

  Its function is to process and output various information from the system, including military intelligence, enemy and friendly situations, combat plans, orders and order execution, in multiple forms such as text, symbols, tables, graphics and images, and display them on each screen.

  Decision Monitoring Subsystem

  Consists of a monitor, keyboard, printer, multi-function telephone, recording device and so on.

  Usually assembled in the form of a workstation, to achieve human-computer interaction, used to assist command personnel in making decisions, issuing commands, and implementing command. It can also be used to change the working state of the command automation system and monitor its operation.

  Execute subsystem

  It can be an automated command system for executing commands of troops, or a device that automatically executes instructions, such as the guidance system of missiles and the fire control system of artillery. The execution situation of the command and the striking effect of the weapon can be fed back to the decision-making monitoring subsystem through the information collection system.

  All kinds of command automation systems will form an overall, coordinated and effective matching system.

  Strategic command automation systems will be further emphasized, tactical command automation systems will develop faster, and the combination with weapon systems will be closer.