19 July 1977

The world’s first Global Positioning System (GPS) signal was transmitted from Navigation Technology Satellite 2 (NTS-2) and received at Rockwell Collins in Cedar Rapids, Iowa, at 12:41 a.m. Eastern time (ET).

The Global Positioning System (GPS) is a satellite-based navigation system that provides location and time information to users anywhere on or near the Earth’s surface. It was developed and is operated by the United States Department of Defense (USDOD). GPS was primarily designed for military use but has since become a crucial tool for civilian applications, ranging from navigation and mapping to scientific research and everyday consumer devices.

Satellites: The GPS system consists of a constellation of at least 24 satellites orbiting the Earth at about 20,200 kilometers (12,550 miles) above the surface. These satellites are spread across six orbital planes to ensure global coverage.

Ground Control Stations: On the Earth’s surface, there are several ground control stations that monitor and maintain the GPS satellite constellation. These stations keep track of the satellites’ positions and health, and they make adjustments to the satellites’ orbits when necessary.

User Receivers: GPS receivers are devices that the general public, as well as various industries and sectors, use to access and utilize GPS signals. These receivers process signals from multiple satellites to calculate the receiver’s precise location, speed, and time.

Triangulation: GPS receivers determine their position by triangulating their distance from at least four satellites in the GPS constellation. By measuring the time it takes for signals from multiple satellites to reach the receiver, the device can calculate its distance from each satellite and pinpoint its position accurately.

Accuracy: The accuracy of GPS varies depending on the number of satellites in view and the quality of the GPS receiver. Most consumer-grade GPS receivers can provide a location accuracy within a few meters, while advanced military and scientific-grade receivers can achieve centimeter-level accuracy.

Selective Availability (SA): Historically, the military introduced SA to intentionally degrade the accuracy of civilian GPS signals for security reasons. However, in 2000, the U.S. government discontinued SA, resulting in a significant improvement in the accuracy of GPS for civilian use.

GPS has become an integral part of modern life, with applications in various sectors, including:

Navigation: GPS is widely used for personal navigation in smartphones, car navigation systems, aviation, marine navigation, and more.
Mapping and Surveying: GPS enables accurate mapping, surveying, and geographical information systems (GIS) applications.
Emergency Services: GPS helps emergency services locate and respond to distress calls more effectively.
Timing and Synchronization: Many critical systems, such as financial transactions, telecommunications, and power distribution, rely on GPS for precise timing and synchronization.
Agriculture: GPS is used in precision agriculture for optimized planting, irrigation, and harvesting.
Geocaching and Outdoor Activities: GPS is used by geocachers and outdoor enthusiasts for treasure hunting and location-based gaming.

19 July 1981

In a private meeting with U.S. President Ronald Reagan, French President François Mitterrand reveals the existence of the Farewell Dossier, a collection of documents showing the Soviet Union had been stealing American technological research and development.

19 July 1903

Maurice Garin wins the first ever Tour de France.

Maurice Garin won the first Tour de France, on July 19th, 1903, by a margin of almost three hours.
Products of the bicycling craze of the 1890s in France included an army regiment mounted on bicycles and numerous flourishing bicycle-connected businesses as well as a public appetite for races. Besides track events in ‘velodromes’, there were long-distance road races, from Paris to Vienna and St Petersburg, for instance, and from Paris to Rome. The Tour de France, which began as a newspaper circulation-booster, was an unexpected by-product of the Dreyfus Affair. In 1899 the bicycle newspaper Le Vélo , which sold 80,000 copies a day, ran a pro-Dreyfus piece that caused a fierce falling out with a major advertiser, the bicycle manufacturer Comte Dion. With other manufacturers, including Clément and Michelin, Dion started a rival sports sheet called L’Auto. The editor was Henri Desgranges, winner of the world one-hour record in 1893. When one of his assistants suggested a race round France, Desgranges saw the possibilities.

The first race in 1903 took nineteen days in six formidable stages, from Paris to Lyon, Marseille, Toulouse, Bordeaux, Nantes and back to Paris. The stages varied in length from 274km to as much as 467km, with a total distance of just over 2400km. A parade of cars, festooned with advertising and throwing free samples to spectators, travelled two hours ahead of the cyclists. Of sixty competitors from France, Belgium, Germany and Switzerland, including professional team riders and freelance amateurs, twenty-one finished the gruelling course and the race was won by a Frenchman, Maurice Garin, ‘the Little Chimney-Sweep’, by a margin of close to three hours. The last finisher came in two days behind.

Garin also won the second race in 1904, but he and the next three finishers were all disqualified for cheating. The early races were notorious for mayhem. Riders strewed broken glass and nails in the road to cause punctures behind them, competitors were given drinks that made them sick, many got surreptitious tows from cars or motorbikes, some were held up and delayed by hired thugs. The excitement was intense and L’Auto’s circulation more than doubled. Le Vélo went bankrupt.

19 July 1553

Lady Jane Grey is replaced as Queen of England by Mary I of England after only nine days on the throne.

6804,Lady Jane Dudley (née Grey)

Tragic Lady Jane Grey is remembered in British history as the monarch with the shortest reign… just nine days.
Why was Lady Jane Grey’s reign as Queen of England so short?

Lady Jane Grey was the eldest daughter of Henry Grey, Duke of Suffolk and she was the great-grand-daughter of Henry VII.She was proclaimed Queen after the death of her cousin, the protestant King Edward VI, son of Henry VIII. She was actually fifth in line to the throne, but was his personal choice as she was a Protestant.Edward’s half-sister Mary, Henry VIII’s daughter with Catherine of Aragon, was actually next in line for the throne but as a devout Catholic, was out of favour.

Edward wanted to keep England firmly Protestant and he knew that Mary would take England back into the Catholic faith.John Dudley, Duke of Northumberland, was Protector to King Edward VI. He persuaded the dying young king to will his crown to Lady Jane Grey, who by coincidence just happened to be the Duke’s daughter-in-law.

Edward died on 6th July 1553 and Lady Jane ascended to the throne with her husband Lord Guildford Dudley at her side – she was just sweet sixteen.

Lady Jane was beautiful and intelligent. She studied Latin, Greek and Hebrew and was fluent in French and Italian.
Queen Mary IHowever the country rose in favour of the direct and true royal line, and the Council proclaimed Mary queen some nine days later.

Unfortunately for Lady Jane, her advisors were grossly incompetent, and her father was partly responsible for her untimely execution as he was involved in an attempted rebellion.This was the Wyatt rebellion, named after Sir Thomas Wyatt, who was an English soldier and a so-called ‘rebel’.

In 1554 Wyatt was involved in a conspiracy against the marriage of Mary to Phillip of Spain. He raised an army of Kentish men and marched on London, but was captured and later beheaded.After the Wyatt rebellion was quashed, Lady Jane and her husband, who were lodged in the Tower of London, were taken out and beheaded on 12th February 1554.
Guildford was executed first on Tower Hill, his body taken away by horse and cart past Lady Jane’s lodgings. She was then taken to Tower Green within the Tower, where the block was waiting for her.

19 July 1952

paavo nurmi
The 1952 Summer Olympic Games were opened in Helsinki, Finland. The games were officially known as the Games of the XV Olympiad. A total 69 nations with 4955 athletes took part in 149 events in 17 sports. The Olympic flame was lit by the Finnish runner Paavo Nurmi. These Olympics were the first competed in by the Soviet Union, Israel and China. Taiwan withdrew in protest at China’s inclusion. The USA, Soviet Union and Hungry won the most medals.