Trimble xFill is an advanced GNSS correction technology designed to maintain accurate positioning when RTK corrections are temporarily unavailable. The system works as a backup correction service that seamlessly fills gaps in RTK connectivity by switching to satellite-delivered Trimble RTX corrections. When an RTK connection is interrupted due to signal loss, poor mobile coverage, or network issues, Trimble xFill automatically continues providing positioning corrections. This ensures that surveyors can maintain accurate positioning without interrupting field operations. Trimble xFill is commonly used with Trimble GNSS receivers in applications such as land surveying, construction layout, infrastructure mapping, and geospatial data collection, where continuous positioning accuracy is critical. Through the Topotronix platform, professionals can access positioning technologies such as Trimble xFill, helping maintain reliable GNSS performance and uninterrupted workflows during surveying and mapping projects.