How Cell Phone Tracking Works

Before GPS was introduced to most mobile phones, triangulating a phone’s location using any of the many techniques available to law enforcement or other government agencies was the only way to track it. 

Most cell phone tracking apps today access the GPS location of the phone and provide feedback to the user via an app or software program. It is necessary to examine each model of cell phone to see the options available for tracking down the desired phone.

What is GPS?

GPS (Global Positioning System), a U.S. satellite-based navigation method, uses a network 24 satellites to provide 3-D data to GPS receivers around the globe. The United States Department of Defense (DoD), maintains the satellites. 

They were initially deployed for military purposes only. The U.S. Government decided in the 1980s to allow civilian use of the satellites and has since removed any restrictions that had been placed on civilian GPS accuracy. GPS can be used by anyone and is available 24 hours a days in any weather. GPS is free to use and there are no subscription or setup fees.

How does GPS work?

The 24 GPS satellites orbit the Earth twice daily in a specific orbit. The satellite transmits information to Earth during their journeys. The information is received by all satellites. 

A GPS receiver calculates the GPS receiver’s exact location by comparing when the satellite transmitted the signal to when the receiver received it. This gives the distance between the satellite and the receiver. 

This difference is used by the GPS receiver to determine the receiver’s position and display it on a chart or map. GPS receivers need at least three GPS satellite signals to receive a 2D position that includes latitude and longitude. 

This is also necessary to track movement. The 3D position (latitude, longitude and altitude) of the GPS receiver unit can be determined if there are at least four satellites visible.

How does the GPS Signal work?

Two low-power radio signals are transmitted by GPS satellites and are called L1 or L2. The L1 signal, which is transmitted at 1575.42MHz (UHF), is intended for civilian use. The signal travels along the line of sight and will penetrate glass, plastic, and clouds. However, most solid objects will stop it. 

The signal contains three pieces of information: almanac data and ephemeris. A pseudorandom code is also included. The code includes an identification for the satellite that is transmitting the information. The ephemeris data includes the current date, time, satellite status, and, most importantly, the GPS signal portion used to determine a location. 

The receiver will know the location of the satellite during the day by the almanac data part of the signal. Each GPS satellite transmits almanac data which indicates the orbital information of the satellite it is tracking, as well as for the other satellites in the constellation.

What factors can affect the accuracy of GPS on cell phones?

Before we get into the details of GPS tracking apps for cell phones, let’s review some factors that could affect the signal accuracy and throw off the location. These factors include signal multipath, ionosphere delays and signal multipath.

  • Atmospheric Delays: The GPS satellite signal travels slower through the Earth’s atmosphere (both Ionosphere, and troposphere). The GPS system uses a scientific model that incorporates an average delay to correct for errors, but there may still be an observable error if there’s an unusual amount.
  • GPS Signal Multipath – When the GPS signal travels slowly because of reflections from tall buildings or large mountains, it can cause delays. This can cause errors in the GPS signal accuracy, and could also affect the location information provided by mobile phone tracking apps.
  • GPS Receiver Clock Problems – The clock built into a GPS receiver or cell phone is not as accurate as the atomic clocks used in satellites. This error isn’t as severe as the others, but it can cause GPS accuracy to be thrown off.
  • Total Number of GPS Satellites Observable – The more GPS satellite signal visible to a GPS signal the better the positioning data will be. The receiver will not be able to provide accurate location information if less than two satellites can be seen.
  • Intentional degradation of GPS signal – While not being used currently (since May 2000), the U.S. Department of Defense still has the ability to cause intentional degradation of GPS signal. This capability is also known as Selective Availability (SA).

Popular Cell Phone Tracking Applications

There are many options to track a phone depending on its model. This task is available on all major smart phones, including Android, iPhone, and Windows.

  • Family Orbit
  • netnanny
  • Norton family safe
  • Numbertrackerpro