If you’re using GPS for construction layout, staking, or machine control, you may be wondering: Do I need a GPS base station?
The answer is yes, but you may not need to purchase one. We’ll start by defining what a base station is and comparing a local to a network base.
What is a GPS Base Station?
A GPS base station is a stationary GNSS antenna that sends correction data to a GPS rover or machine-control system. Both local and network bases perform the same basic function: providing correction data that helps the rover achieve accurate positioning. The difference is where the base is located and how your rover receives its corrections.
Local Base Station
A local base is set up at or near your jobsite, usually over a known control point or on a semi-permanent mount. It communicates with your rover or machine through radio, internet, or both. The downside is that a local base generally requires setup each day unless it can remain mounted on the same point. Radio range can also be affected by trees, hills, buildings, and other obstructions. A general rule of thumb, radio corrections can be transmitted up to about a mile over water.
A local base may be a good choice if you:
- Work in areas without a network base
- Have unreliable cellular service
- Work on large or remote projects
Network Base Station
A network base is a permanent GPS base station that sends correction data to your rover via cellular/the internet. Many state DOTs and private organizations operate these networks, with some offering free access and others requiring a subscription. A network rover does not require an onsite base setup making it a convenient option for many contractors.
A network base may be a good choice if you:
- Work within an established network
- Have reliable cellular service
- Want minimal setup time
- Don’t want to purchase a local base
How Far Can You Be From a Network Base?
One of the most important factors is the distance between your jobsite and the nearest network base station. This is known as the baseline.
As a general guideline, it is recommended to stay within approximately 15 miles of a network base, with closer being better. However, the actual usable distance can vary based on the network, satellite constellations, correction method, and jobsite conditions.
Your surroundings matter, too. Heavy tree coverage, hills, and tall buildings can affect GPS performance, so two jobsites the same distance from a base may not have the same results.
Your current equipment and future plans should also factor into the decision. If you operate multiple rovers, a local base may become more cost-effective as opposed to paying for multiple network subscriptions.
How Do I Know If I Need to Buy a Base Station?
Before purchasing a local base, ask yourself the following questions (or give us a call at 207-800-5369):
1. Is there a network available?
Find out whether a state or private GPS base station network covers the area where you work. If you’re unsure, a simple Google search with your state’s name followed by “NTRIP”. Or feel free to reach out to us and we’ll be happy to check for you. If there is no base network available, you will need to purchase a base station or utilize a subscription-based service.
2. How far is your jobsite from the nearest base?
Determine your baseline distance. Google Earth can be useful for estimating the distance.
3. Do you have reliable cellular service?
Network bases require an internet connection. If you can’t reliably access the internet from your jobsite, a local base may be a better option.
4. How many GPS systems do you use?
Consider both your current fleet and your plans for future GPS rovers and machine-control systems.
If a network provides adequate coverage, your jobsite has reliable cellular service, and the network meets your equipment requirements, you may not need to purchase a local base station at all.
Need Help Choosing a GPS Base?
If you’re unsure which option makes sense for you, the SiteBoss team can help you evaluate your setup and determine what you actually need. Send us a message or give us a call at 207-800-5369. We’ll be happy to assist you!
Whether you’re purchasing your first construction GPS system or replacing/supplementing an existing setup, we’ll help you find the right solution without paying for equipment you don’t need.
