Surveying & GNSS

GNSS Best Practices

Global Navigation Satellite Systems power everything from mapping and surveying to navigation and geolocation. Survey-grade accuracy, though, comes from disciplined field practice. This guide walks through the workflow — preparation, base station setup, rover collection and post-processing — for clean, repeatable GNSS data.

Goal
Centimeter-level, repeatable positions in the field.
Method
A stationary base station correcting one or more roving receivers (RTK / DGNSS).
Key levers
Clear sky view, stable setup, accurate antenna height, good satellite geometry.

1. Understanding GNSS Fundamentals

Before getting into field practice, it helps to be clear on the building blocks:

  • GNSS satellites broadcast the signals used to determine a receiver’s position.
  • GNSS receivers capture those signals and compute their own location.
  • Base station — a stationary receiver that broadcasts correction data, sharpening the accuracy of the rover units working nearby.

2. Choose the Right Setup Software

To set up your base station and rover, we recommend the tools from Carlson Software, an industry leader in GNSS that has served the professional survey industry for over 40 years.

For GNSS setup we suggest SurvPC on Windows or Carlson Layout on Android. For demanding work, look at the Carlson Gama Engine, a high-end RTK engine with best-in-class accuracy.

Carlson Instruments

3. Pre-Survey Preparation

  • Make sure every piece of equipment — receivers, antennas, data collectors — is fully charged and in good condition.
  • Verify that firmware and software are up to date.
  • Scout the survey area for obstructions such as tall buildings, dense trees or steep terrain.

4. Base Station Setup

A solid base station is the foundation of differential GNSS (DGNSS) and real-time kinematic (RTK) surveys, both of which depend on it for high accuracy.

4.1 Location Selection

  • Choose a site with a clear, open view of the sky, free of obstructions.
  • Place the base somewhere stable and secure so it cannot move during the survey.

4.2 Setup Process

  • Antenna placement: mount the antenna on a stable tripod or fixed structure. Use a tribrach with an optical plummet to level and center precisely over a known point.
  • Antenna height: measure and record the height from the survey point to the antenna phase center.
  • Initialization: let the base acquire satellites for at least 15–30 minutes before you begin.

4.3 Logging and Transmission

  • Set the base to log raw data for post-processing, or broadcast real-time corrections over radio or internet (NTRIP).
  • Check the connection and logging status regularly throughout the day.
★

Measure the antenna height twice

An incorrect antenna height is one of the most common causes of a systematic vertical error across an entire survey. Record it, and confirm it, before you collect a single point.

5. Rover Unit Field Collection

  • Connect the rover to the base over radio or internet (NTRIP).
  • Let the rover initialize and reach a Fixed solution before collecting data.
  • Minimize multipath by staying clear of reflective surfaces — water, metal and glass near the survey area.
  • Work during good satellite geometry (a low PDOP — Position Dilution of Precision).

In Summary

Accurate GNSS results come from thorough preparation, a precise base station, disciplined field collection and careful post-processing. Follow these practices and you’ll capture high-quality data — whether the job is a quick mapping task or an intricate geospatial survey.

See Also

Setting Up GPS Carlson Software