Satellite navigation device

A satellite navigation device, also called a satnav device or GPS/GNSS device, uses satellites to find out where you are. It can show your spot on a map and tell you how to get to places.

There are four main systems that help find your location: the United States' Global Positioning System (GPS), the European Union's Galileo, Russia's GLONASS, and China's BeiDou. These systems work together to give better results.

A satellite navigation device can find your location and the time, no matter the weather, almost anywhere on Earth. It needs to see four or more satellites in the sky. Today, many cars have these devices built-in. Smartphones can also find your location using help from nearby cell towers.

History

Further information: Global Positioning System § History

Satellite navigation devices started during the Cold War. The United States and Russia made them first for their militaries. Later, other countries made systems for everyone.

In 1960, the US Navy used satellites to help ships. Over time, the technology got better. In 1983, after an airplane accident, President Ronald Reagan let people use the system too, but it was not very exact at first. The first commercial GPS device, the Magellan NAV 1000, came out in 1989. Soon, cars started having navigation systems. By 2000, everyone could use the full system.

These systems became popular and cheaper. Many companies made them, and now most smartphones have GPS. Besides the US GPS, other countries have their own systems, like Russia's GLONASS, the European Union's Galileo, and China's BeiDou Navigation Satellite System.

Technical design

GNSS devices have different abilities. Some can pick up weak signals quickly, helping them find your location fast when you're outside. Even when signals are weak, like inside a building, these devices can still work by using extra power to find faint signals.

The signals from GPS satellites are weak when they reach Earth. They become even weaker by the time they reach a device on the ground. Some devices are made to pick up these weak signals, which lets them work even inside buildings, though they might not work everywhere. These special devices can sometimes see through walls or thick materials to find your location.

Types

Consumer GNSS navigation devices come in several forms:

• Dedicated GNSS navigation devices: These are special tools made just for finding your way. Some are small and easy to carry, good for hiking or biking. Others are made to use in cars and can show maps and give directions.
• Modules that connect to computers: These devices need to be linked to a computer to work. They can record trips and are useful for activities like hiking and making maps.
• Converged devices: Many modern devices, like phones and cameras, have GNSS as one of their features. These can also show maps and help with finding places.

Almost all smartphones today have GNSS, which lets them show maps and help with navigation. There are many apps for this, such as Google Maps Navigation, Apple Maps, and Waze.

Dedicated devices can be used while moving. Hand-held ones have batteries that last for hours and are good for activities far from power outlets. They are built to be strong and some can even work in water. Some devices for cars have touch screens and can store maps on memory cards.

Modern devices often show maps and can give step-by-step directions, sometimes talking to you. Companies that make these devices include Navman products, TomTom products, Garmin products, Mio products, Navigon products, Magellan Navigation consumer products, Satmap Systems Ltd, and TeleType products.

Other GNSS devices need to be connected to a computer, like a home computer, laptop, or smartphone. They can connect using different methods, such as USB or Bluetooth. These devices usually need the user to install special software to make them work. Some come with software already.

Applications

Vehicle navigation

An automotive navigation system uses satellites to find your location. It can show you maps and give you directions. It can even help self-driving cars. It can show traffic and suggest better routes. It can also point out places like restaurants or gas stations.

Aviation

Aviators use satellite navigation to fly safer and more efficiently. This helps pilots fly without needing help from the ground. It can guide them to airports without special equipment. Some GPS units help pilots see better in poor weather. Many airlines now require pilots to use GPS. These devices give information to computers that control the plane and show courses to pilots.

Military

The military uses satellite navigation devices for soldiers, vehicles, ships, planes, and missiles. Before May 2000, only the military could use the most accurate GPS signals. Now, everyday devices can also get very precise location information using a method called Differential GPS.

Risks

GPS maps and directions can sometimes be wrong. This may cause people to get lost or end up in unexpected places, like private driveways that aren’t actual streets.

There are also privacy concerns with satellite navigation devices. When using these devices on phones or other gadgets, they might share your location with apps and advertisers. This means companies could know where you go and what you do. Some employers also use these tools to track their workers, even when they’re not working. This can feel like an invasion of privacy.