Frequently Asked Questions About GPS

GPS technology is one of those technologies that’s so common yet nobody really thinks about. Do people know how the satellites work? Do people even know that GPS is an acronym? Are they even interested in learning?

You are, obviously. Which is why you’re reading this article (and we’re glad you’re here). You want to learn more about GPS, and we want to teach you! So let’s begin:

What does GPS stand for?

GPS means “Global Positioning System.” It’s a system that uses a combination of satellite and radio technology to determine the position of GPS receivers located anywhere on the planet. GPS technology was developed in the 1960s, based on satellite navigation experiments conducted by the United States.

In 1978, the United States Department of Defense launched a series of satellites in order to build a network and advance the system for military applications. It wasn’t until the year 2000 that this “selective availability” was removed, which made GPS fully available to civilians for personal and commercial use. 

Who invented GPS?

GPS wasn’t invented by one person, but rather by a group of people: Roger L. Easton, Ivan A. Getting, and Bradford Parkinson.

• Roger Easton was a scientist and creator of the U.S. Naval Space Surveillance System, which was a crucial step in the development of GPS. 

• Ivan Getting was the founding president of The Aerospace Corporation, and pressed for an advanced system of satellites that could track rapidly moving vehicles.

• Bradford Parkinson was the first manager of the NAVSTAR GPS program. As an Air Force colonel, he met the challenge of combining existing discoveries and technologies to create a functioning system. 

• Dr. Gladys West isn’t part of the original group, but her computational work was also instrumental in this technology’s development. She was a mathematician who worked in the Naval Weapons Laboratory, made critical calculations that made it possible to determine the exact location of satellites and ensure the accuracy of the GPS system. 

Why is GPS free?

It originally wasn’t. At first, the US military wanted to restrict access to GPS for security reasons. But in 1983, the Soviet Union shot down a Korean passenger jet that strayed from its intended route. This was a mistake that GPS could’ve prevented, and so President Ronald Reagan allowed the public to use the system (albeit with reduced accuracy) in a program called Selective Availability. 

In 2000, President Bill Clinton ended Selective Availability and opened it up to full, unlimited access by private citizens and corporations. Full, free access to GPS technology allowed for more innovations like real-time, turn-by-turn driving directions, GPS tracking for packages, geofencing, and more. These advances have increased people’s safety and fueled productivity and economic growth for both the US and abroad.

How does Global Positioning work?

GPS relies on a process called “trilateration,” which is using the distance of three or more satellites to calculate location. The Federal Aviation Administration (FAA) explains that GPS receivers determine their location by computing the difference between the time that a satellite signal is sent, and the time it’s received. 

GPS receivers like smartphones and navigation hardware use this data to determine the satellite’s location and how far away it is. Data from one satellite narrows a receiver’s possible location down to a radius on Earth within that distance. A second satellite provides enough information to further narrow down the possibilities. The third satellite makes trilateration–determing a single exact location from three reference points–possible.

How do GPS satellites work?

GPS Satellites work mostly by transmitting data from atomic clocks. There are over 30 GPS satellites orbiting the Earth right now. These satellites constantly emit radio signals that broadcast the location of the satellite and the time each signal was sent.

This allows receivers to calculate their own location based on how long it takes the signal to reach them. Atomic clocks are too expensive to put in every GPS receiver, which makes it difficult to sync with satellites. To make up for this, GPS receivers constantly reset their clocks to match the time data sent by multiple satellites. Thus, GPS satellites help maintain the system by simultaneously delivering location and time information from their atomic clocks.

How do GPS trackers work?

GPS trackers contain both GPS receivers and data loggers / transmitters. Data loggers make it possible to see where a tracker has been. Data transmitters make it possible to track the real-time location and movements of a GPS tracker.

An example of a GPS tracker using a data logger is a digital camera. Photos can be geo-tagged with the location they were taken. Data transmitters are more common for GPS trackers that are used to monitor packages, assets, and vehicles in motion.

How does GPS work with cellphones?

While GPS transmits radio signals via satellites, cell phones use radio towers. These technologies can be combined into something called wireless-assisted GPS or enhanced GPS. 

Enhanced GPS makes it possible to determine a receiver’s location more quickly. Data about how far a phone is from nearby cell towers is added to data from GPS satellites. Most smartphones today have GPS ability and a data plan that supports transmission of maps and GPS data. 

This makes it possible to get turn-by-turn directions or track the whereabouts of a cellphone.

Can I use GPS without data?

GPS by itself doesn’t require a cellular connection to work. In fact, the technology is very popular for activities in remote locations where cellular data is scarce or nonexistent. That being said, latitude, longitude, and altitude are rarely useful for the average user. To get the full benefits of GPS, you’ll need to download apps and maps ahead of time that can translate GPS signals into the information you need.

Also note that using GPS trackers is a whole different story entirely, as they need a cellular connection in order to transmit their location to the user.

Does GPS work without Wi-Fi?

Yes, GPS works without Wi-Fi. However, there is a caveat. Many GPS devices like navigation systems, trackers, and smart watches have built-in technology that overlay a user’s GPS location on a map. Without these maps, most people will have trouble getting the most use out of GPS. For this reason, if you plan on using GPS on a smartphone or similar device, you should download maps and apps that can be used offline.

Does 5G interfere with GPS?

Sometimes. Under certain circumstances, 5G could potentially interfere with GPS. 

In April 2020, the FCC approved an application from a company called Ligado Networks to deploy 5G in a manner that may interfere with GPS. There was concern that Ligado’s proposed transmission power could “exceed the thresholds established by the GPS Adjacent Band Compatibility study to protect GPS users from harmful interference.”

Ligado wants to deploy a low-power, high-traffic 5G network on a radio band adjacent to GPS bands. The amount of traffic on the 5G network could drown out GPS radio signals and cause the technology to fail.