GNSS/GPS Reference Stations: The Backbone of Modern Surveying

Surveyors, civil engineers, and construction crews across the U.S. rely on GNSS/GPS reference stations to deliver the precision required for roads, subdivisions, commercial developments, and environmental projects. These reference stations serve as the backbone of RTK (Real-Time Kinematic) GPS workflows, providing the corrections that allow rovers to achieve centimeter-level accuracy.

Without a properly set up reference station, even the most advanced GNSS receivers like the Hemisphere S631 or GeoMeasure Nano 7 can produce data that is off by feet, leading to rework, project delays, and costly errors. 

According to industry estimates, survey inaccuracies can add 5–10% in unexpected costs to infrastructure projects, which is a significant impact on tight budgets. At Bench Mark, we’ve helped U.S. crews get the most out of their equipment. This guide will cover everything you need to know to ensure reliable, precise, and consistent field data.

How GNSS/GPS Reference Stations Work
Common Mistakes with Reference Stations
Best Practices for Reference Stations
Accuracy Starts with Your Reference Station
FAQ

How GNSS/GPS Reference Stations Work

A GNSS/GPS reference station is a fixed receiver that continuously calculates its position using satellite signals. Because the station’s true location is precisely known, it can measure small satellite errors in real time and broadcast correction data to nearby rovers. This enables survey crews to convert standard GNSS measurements, often accurate to meters, into centimeter-level positions.

Think of the reference station as an anchor for your project. Every rover in the field relies on it to align measurements. If the reference station is unstable, improperly located, or incorrectly configured, the errors propagate to every point collected by your team. That’s why proper setup is not “turn it on and go.” It includes choosing the right location, using the correct base mode, and ensuring stability for the duration of your survey.

Common Mistakes with Reference Stations

Even experienced teams occasionally make errors that compromise data quality. Below are three of the most frequent mistakes, and how to avoid them:

Mistake 1: Using Known Points Without True Coordinates

Symptom: Rover shows an error such as “Too far from known point to set up base.”

Cause: The base station is being placed over a survey monument with only local coordinates (Northing/Easting) rather than geodetic coordinates (latitude/longitude). Many surveyors assume local coordinates are enough, but software like FieldGenius requires geodetic data for the Known Point setup.

Fix: Use the Local Transformation to Point mode. This links the GPS location of the base to the local project grid, ensuring all points are properly referenced. Always verify whether your “known” point is geodetic or local before starting.

Mistake 2: Averaging the Base Across Multiple Days

Symptom: Data collected on consecutive days is shifted consistently, often by a foot or more.

Cause: The Averaged Position method was used on the second day rather than returning to the same saved coordinates. The base’s estimated position changes slightly each day, creating systematic offsets.

Fix: Always save your base coordinates after the first day and use Known Point setup on subsequent days. Only use Average Position for initial, first-day setups. This ensures consistency across multiple survey days and avoids costly rework.

Mistake 3: Multiple Local Transformations Without Resetting

Symptom: Points on the same location are inconsistent between days. Data appears “wonky” or rotated.

Cause: A new Local Transformation is created each day, but the GPS coordinates vary slightly. The software tries to tie each new set of coordinates to the same local point, creating chaos.

Fix: Save both the GPS and local coordinates after the first transformation. On return visits, use Known Point setup with the saved transformation or reset and carefully redo the Local Transformation if necessary.

Best Practices for Reference Stations

Beyond avoiding mistakes, adopting solid habits ensures consistent, reliable data:

• Stable Tripod Setup: Even slight movement can propagate significant errors to your rover.
• Open Sky Placement: Avoid trees, buildings, and reflective surfaces that cause multipath errors.
• Mark Base Points: Use nails, flags, or stakes to easily return to the same position.
• Double-Check Coordinates: Verify both geodetic and local coordinates before collecting data.
• Document Everything: Keep a log of base setups, project configurations, and environmental conditions for future reference.
• Leverage Software Resources: Search for tutorials, cheat sheets, and troubleshooting guides, available anytime in the field.

Accuracy Starts with Your Reference Station

Investing time in proper base setup and training also provides long-term benefits: crews work faster, make fewer mistakes, and produce data that meets or exceeds industry standards. By combining well-trained operators, solid field practices, and accessible resources, your team can maximize the performance of advanced GNSS equipment.

GNSS/GPS reference stations are the heart of RTK workflows. Set them up correctly, and survey teams will collect high-precision data efficiently and reliably. Proper training and consistent workflows reduce errors, improve efficiency, and save significant costs on U.S. infrastructure projects.

A well-maintained and properly configured reference station improves data and underpins every measurement your team takes and every decision made on the project. Treat your reference station like the backbone it is, and your surveys will reward you with precision, efficiency, and confidence.

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