The primary objective of the LC-HERC2 project is to evaluate whether the sensitivity of low-cost GNSS receivers can be significantly enhanced by utilizing external atomic clock corrections. To achieve this, the research team installed Septentrio mosaic-X5 receivers at the Corinth Rift Laboratory (CRL) at two specific sites: UPT1, which is supplied with an external rubidium clock, and UPT2, which utilizes an internal clock. These receivers were co-located with professional geodetic stations via signal splitters to ensure simultaneous data acquisition from shared antennas for comparative analysis. The resulting dataset consist of 1 Hz RINEX observation data from low-cost stations UPT1, UPT2 & geodetic-grade station PAT0 (EUREF CORS station), and real-time Precise Point Positioning (PPP) outputs from UPT1 & UPT2 processed with BNC software (including Cartesian ECEF coordinates, NMEA formatted logs, phase and code residuals, and tropospheric zenith total delay records). Any additional information is available upon resonable request to the Authors. Acknowledgement: The study (project ID: C2_TA3-88-2_1) was supported by Transnational Access (TA) activity by the Geo-INQUIRE project. Geo-INQUIRE is funded by the European Union (GA 101058518).