A brief guide to GIS terminology

Like many industries, the GIS field is full of acronyms and niche terminology. Keeping them straight—and understanding their nuance—can be challenging. That’s why we wrote up this brief—yet ever-growing—guide to the most common acronyms and buzzwords in GIS.

What is GIS?

GIS stands for geographic information system. A GIS is a computer system for capturing and managing geographic and global positioning data. A GIS combines hardware, such as a GNSS receiver or base station, with software to create user-friendly displays of geographic information. In the utilities industry, for example, GIS may be used to create a map displaying the location of assets, such as pipes, sewer lids, and fire hydrants, within municipal boundaries.

What is GNSS?

GNSS stands for global navigation satellite system. It’s a generic term for a satellite network that provides geopositioning, timing, or navigation data and doesn’t refer to any specific group or constellation of satellites. A GNSS receiver can receive signals from many systems, the four systems with global coverage for RTK are GPS, GLONASS, BeiDou, and Galileo.  SBAS signals are available for sub-meter applications. 

What is RTK?

RTK stands for real-time kinematics. RTK corrections can be applied to GNSS data in real time or in post-processing. In real time, a GNSS receiver receives a real-time stream of RTK corrections from a nearby base station that calculates the receiver’s location to within a single centimeter on earth. In post-processing, RTK corrections are applied to GNSS data after the data has been collected and uploaded to the appropriate application.

What is SBAS?

SBAS stands for Satellite-Based Augmentation System. An SBAS is a regional system of geostationary satellites and ground systems that augments GNSS data to achieve greater accuracy and precision. An SBAS may cover a single country, such as the Wide Area Augmentation System (WAAS) operated by the FAA in the United States, or a larger region, such as the European Geostationary Navigation Overlay Service (EGNOS) in the European Union.

What is sub-meter accuracy?

Sub-meter accuracy is the level of precision delivered by SBAS GNSS data. Contrary to what the name suggests, sub-meter accuracy does not guarantee accuracy within one meter. Generally, sub-meter accuracy is accurate within roughly two meters, but there is no formal guarantee of accuracy range or any way to mathematically prove SBAS coordinates. That being said, SBAS is sufficient for a wide variety of applications.

What is sub-centimeter accuracy?

Sub-centimeter accuracy, or centimeter-level accuracy, is the level of precision delivered by RTK-corrected GNSS data. Centimeter-level accuracy is reliable and provable, thanks to real-time kinematics, and is valuable for applications where greater precision is required. 

Whether you’re new to GIS or have years of experience in the field, you can trust E38 Survey Solutions to provide reliable GIS solutions and unmatched customer support. We can help you upgrade your fleet, expand your business, or break into the field with the right combination of receivers, base stations, and other GIS tools.

Talk to a member of our team >