GNSS Best Practices

Global Navigation Satellite Systems (GNSS) provide valuable data for a myriad of applications, ranging from mapping and surveying to navigation and geolocation. To ensure the highest accuracy of GNSS recordings, meticulous field collection practices are essential. This article outlines the best practices for obtaining precise GNSS data, including setting up a base station.

1) Understanding GNSS Fundamentals

Before diving into field practices, it’s crucial to understand GNSS basics:

GNSS Satellites: Provide signals used to determine the precise location of receivers.
GNSS Receivers: Devices that capture satellite signals and calculate the receiver’s position.
Base Station: A stationary GNSS receiver that provides correction data to enhance the accuracy of other receivers in the field (rover units).

2) Choose the right Setup Software

In order to setup your base station and rover, we recommend utilizing the tools provided by Carlson Software, an industry leader within the world of GNSS. Carlson Software has served the professional survey industry for over 40 years.

For setting up GNSS we recommend using SurvPC for Windows or Carlson Layout for Android. In addition we recommend checking out the Carlson Gama Engine, a high end RTK engine with highest in-class accuracy.

3) Pre-Survey Preparation

4) Base Station Setup

Setting up a base station is critical for differential GNSS (DGNSS) or real-time kinematic (RTK) surveys, which require high accuracy.

4.1 Location Selection:

Choose a site with a clear view of the sky, free from obstructions.
Ensure the base station is in a stable and secure location to prevent movement 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 for precise leveling and centering over a known point.
Antenna Height: Measure and record the antenna height from the survey point to the antenna phase center.
Initialization: Allow the base station to initialize and acquire satellite signals for at least 15-30 minutes before starting the survey.

4.3 Logging and Transmission:

Set the base station to log raw data for post-processing or broadcast real-time corrections via radio or internet (NTRIP).
Regularly check the connection and data logging status.

5) Rover Unit Field Collection

Conclusion

Accurate GNSS recordings hinge on thorough preparation, precise base station setup, diligent field collection practices, and meticulous post-processing. By adhering to these best practices, surveyors can ensure high-quality GNSS data for their projects, leading to reliable and accurate results. Whether you’re conducting a simple mapping task or an intricate geospatial survey, these guidelines will help you achieve the best possible outcomes.