How Accurate Is GPS?
Has your Uber app ever displayed the wrong pick-up location on its map? Has Google Maps ever shown you standing on the opposite side of the street? You might be wondering how accurate are GPS unit coordinates.
The answer is: It all depends.
Various factors can affect GPS accuracy, so it’s not surprising when smartphone apps give you misleading data. Overall, though, GPS works well enough to pinpoint locations reliably. Depending on your device’s GPS technology, though, you could get accuracy anywhere from a millimeter to about five meters. How accurate is GPS, and how can you get more reliable information from the GPS positioning system? Let’s answer these and other questions so you can enjoy better accuracy.
How Does GPS Work?
The Global Positioning System (GPS) comprises over 30 navigation satellites that orbit the planet. These satellites constantly send signals to GPS receivers in smartphones or standalone GPS devices. A receiver then calculates its distance from four or more satellites to determine your location. But how accurate is that location? That is what we are going to discuss in this article!
Factors That Affect GPS Accuracy
Signal blockage and atmospheric conditions are two of the most common factors that can disrupt GPS accuracy.
Signal Blockage
Let’s say you’re standing in downtown New York City. You pull out your GPS device to get directions to a neighborhood restaurant. To your surprise, the device says you’re standing far down the street.
What happened?
More likely than not, your device got confused because a tall building blocked the GPS satellite signals.
If you walk into an underground garage, you might not get any location information at all.
When the environment around you blocks signals, you can’t expect a GPS device to calculate your location accurately. It just doesn’t have enough information to do the job.
Atmospheric Conditions
Heavy cloud coverage, storms, and other atmospheric conditions can also interfere with satellite signals. Those signals can bounce off thick cloud coverage, making it impossible for devices on the surface to calculate their locations. The signals might also ricochet off clouds and other obstructions, tricking your GPS unit into thinking it’s somewhere else.
Other Factors That Degrade GPS Accuracy
Equipment failure can also degrade GPS accuracy. For example, if a base station loses power, it can’t make necessary adjustments.
Luckily, equipment failures get addressed pretty quickly. The government and private companies know that people need accurate GPS. It goes far beyond ensuring you have good directions to reach a destination. Companies use GPS data to make vehicle fleets more efficient. Warehouses use GPS to manage inventories. Even farmers need reliable GPS to do their jobs well.
Given the importance of GPS in today’s economy and culture, equipment failures are serious concerns.
Real-World Reasons GPS Accuracy Matters
Obviously, people want GPS technology that provides accurate location data. In some cases, though, GPS accuracy matters more than others.
GPS Location Data Leads to Murder Conviction
In 2007, a 12-year-old babysitter died on a farm in Chenango County, New York. The suspect, George Ford Jr., said the girl died when he accidentally ran over her with his truck. Prosecutors debunked his testimony, though, by accessing location data from a LandAirSea device Ford’s wife had placed in the vehicle.
She’d wanted evidence of marital infidelity. Instead, she captured evidence showing that Ford had never visited the pasture where he says the accident happened. Instead, he spent three hours behind an abandoned farmhouse.
Prosecutors used this evidence to successfully argue that the girl had run away from Ford’s truck. Ford chased her down and intentionally ran over her with the vehicle.
Thanks to accurate GPS data, a man was convicted of killing a young girl.
GPS Accuracy Helps Predict Natural Disasters
An article published in Scientific American explains how scientists are using GPS to predict natural disasters. Their predictions could help save thousands of lives.
Using high-end GPS receivers intended for scientific research, experts have been able to:
- Compare shifts at different ends of transform faults, like the San Andreas Fault, to predict earthquakes
- Monitor the land around volcanoes to detect magma moving toward the surface, making it possible to predict volcanic eruptions earlier
- Measure snow and ice depth in places like Antarctica to collect information about the effects of climate change
- Measure the amount of water vapor in the atmosphere to predict floods
Accuracy of Different GPS Technologies And Devices
The GPS device you use can radically affect accuracy. Your smartphone contains a GPS chip that lets it receive satellite signals. Smartphones, however, are only accurate within 4.9 meters.
Many smartphone manufacturers take a dual-frequency approach to improve accuracy. For example, your mobile device might use GPS signals and cellular signals. Often called enhanced GPS and wireless-assisted GPS, information from both signals makes it possible for your phone to calculate your location more accurately.
If you don’t have access to your cellular network, though, this enhanced system doesn’t work.
Stand-Alone GPS Trackers
Stand-alone GPS trackers often offer better accuracy than multi-use smartphones. High-end GPS devices can measure distances as small as a millimeter.
LandAirSea GPS trackers fall somewhere between smartphones and the high-end devices often used by the military. You can expect LandAirSea’s stand-alone GPS devices to give you accuracy within 1.8 meters. Like with other civilian GPS trackers, you get improved accuracy when the device can communicate with satellite and cellular signals.
Improving The Accuracy of GPS Signals
GPS’s accuracy has improved over the decades. Here are some of the technologies that make the system more effective.
Differential Global Satellite Positioning (DGPS)
Differential GPS uses ground-based reference stations to improve the accuracy of GPS calculations. Early global navigation satellite systems (GPSS) were only accurate within 20 to 30 meters. The ground stations made it possible for some receivers to calculate accuracy within millimeters.
DGPS’s usefulness depends on how close you are to a reference station. The farther away you get, the less effective they are.
Assisted GPS (A-GPS)
A-GPS refers to the multi-signal technologies that typically use cellular data to supplement GPS data, resulting in greater accuracy. It’s the same technology LandAirSea uses to boost positioning accuracy in the LandAirSea 54, LandAirSea Overdrive, and LandAirSea SYNC.
Smartphones vs. Standalone GPS Units – Which Are More Accurate?
The GPS on your smartphone might help you find your nearest Chinese restaurant or grocery store, but it’s not as precise as you think. Smartphones are usually accurate within a 4.9-meter radius, which is less than a high-quality standalone GPS device. That 4.9-meter radius might mean your Uber driver picks you up on the opposite side of the street. Or you turn up at the wrong building for an important job interview and wonder how accurate are GPS unit coordinates anyway?
Take a device like the LandAirSea 54, which according to US News, is the best budget solution for tracking vehicles, assets, and people via 4G LTE. This mini GPS tracker has a location accuracy of 1.8 meters (5.97 feet). That means it’s far more accurate than an iPhone or Samsung Galaxy. How? The answer comes in the way the technology works. Cell phones use something called cellular triangulation to determine position. Although this is usually good enough to help you navigate your way home, it is far less accurate or reliable than real time GPS tracker. This is because GPS trackers use actual GPS signals to determine location vs cell towers.
Learn more about GPS satellite tracking here: https://landairsea.com/blog/what-is-satellite-tracking/
Why Is GPS Tracking Accuracy Important?
You might think that a couple of meters won’t make a difference when it comes to GPS. That’s not true for everyone. Many business leaders need maximum GPS accuracy when carrying out day-to-day tasks, and smartphones just won’t provide them with the precision they need. Take a busy warehouse with thousands of products, for example. Say a manager attaches a standalone GPS asset tracker to an item so she can quickly locate it later. A GPS accuracy of 1.8 meters (compared to 4.9 meters) could save her a considerable amount of searching time.
That’s why standalone GPS products provide much more value than smartphones.
How Accurate Are GPS Unit Coordinates? It’s Not Always The Device
Sometimes, it’s not the GPS tracking unit that’s inaccurate but the mapping software the device relies on to determine a location. Some mapping programs have mislabelled buildings, missing roads, and badly-drawn maps. Often, GPS device manufacturers have no control over these maps and can’t make changes themselves.
LandAirSea products use various mapping programs such as Google Earth, Google Maps, and the Silvercloud App, as well as GPS technologies such as geofencing.
Other Benefits Of GPS Devices
As well as typically being more accurate than smartphones, standalone GPS devices provide the following benefits:
- Batteries in standalone GPS devices last for much longer than those in smartphones. LandAirSea products, for example, come with a battery that lasts for up to 12 months. You can even use Powersaver mode to conserve battery life.
- You can attach smaller GPS devices to vehicles and high-value items and track inventory, assets, and employees. LandAirSea products provide you with real-time location data that you can use to improve workplace productivity, enhance customer service, and prevent theft and loss. You can attach one of these devices to an item with the provided magnets or adapter cables.
- GPS devices are generally more robust than delicate smartphones. Designed to be used in various weather conditions and terrains, devices such as the LandAirSea 54 provide extreme durability.
Final Word
How accurate are GPS unit coordinates? It all depends on the device. While signal blockage, atmospheric conditions, and other factors can impact GPS quality in any product, standalone devices are often more accurate than smartphones. Investing in one of these devices can ensure you determine the right location when tracking inventory, vehicles, and other high-value assets.
Learn more about LandAirSea’s incredible range of GPS trackers for security, performance, customer service, asset protection, and inventory management.