ISO 17123-8:2015

Overview

ISO 17123-8:2015 specifies standardized field procedures for testing the precision and repeatability of Global Navigation Satellite System (GNSS) field measurement systems, especially those operating in real-time kinematic (RTK) mode. Developed by the International Organization for Standardization (ISO), this part addresses GNSS RTK equipment and their ancillary devices as used in geodetic, surveying, and various industrial measurement applications. The procedures provided are intended as practical field verifications to assess the suitability of specific GNSS RTK instruments for immediate project tasks, ensuring accuracy and compliance with existing standards.

Key Topics

• GNSS Field Measurement Systems: Covers systems using current (such as GPS and GLONASS) and future satellite navigation technologies (such as GALILEO), operating in real-time kinematic (RTK) mode.
• Field Procedures: Includes both a simplified and a full test procedure for determining precision. The simplified procedure offers quick verification, while the full procedure provides in-depth statistical assessment and repeatability analysis.
• Measurement Precision and Uncertainty: Focuses on evaluating the repeatability of GNSS measurements, as well as assessing and quantifying measurement uncertainty for both position and height.
• Influence Factors: Identifies key factors that can affect measurement results, such as satellite configuration, atmospheric conditions, multipath interference, and instrument setup.
• Statistical Evaluation: Describes methods for performing statistical tests, calculating standard deviations, and creating an uncertainty budget according to ISO and GUM (Guide to the Expression of Uncertainty in Measurement) principles.

Applications

• Land Surveying & Construction: Ensures GNSS RTK systems meet needed precision for construction site layouts, boundary determinations, and topographic surveys.
• Industrial Measurements: Verifies real-time kinematic GNSS equipment for use in industrial positioning, machine guidance, and structural monitoring applications.
• Building & Engineering Projects: Provides a reliable method for confirming that GNSS RTK instruments and their ancillary equipment are suitable for specific building and engineering tasks, complying with project precision requirements.
• Quality Control: Helps operators detect equipment issues early, verify repeatability in the field, and document GNSS receiver performance in alignment with organizational or regulatory standards.
• Instrument Comparison & Selection: Offers a consistent basis to compare different GNSS RTK systems and select the most appropriate solution based on documented field performance.

Related Standards

Adoption of ISO 17123-8:2015 is most effective when used in tandem with other key standards:

• ISO 17123-1: Theory of field procedures for geodetic and surveying instruments.
• ISO 17123-2: Procedures for testing levels.
• ISO 17123-5: Testing procedures for total stations.
• ISO 12858-2: Guidelines for ancillary devices (tripods) for geodetic instruments.
• ISO 3534-1: Statistical vocabulary and symbols.
• ISO/IEC Guide 98-3: Guide to the expression of uncertainty in measurement (GUM).
• ISO/IEC Guide 99: International vocabulary of metrology.

Practical Value

Through standardized procedures, ISO 17123-8:2015 directly supports professionals in surveying, construction, geodesy, and industry with:

• Reliable Field Verification: Supports confident deployment of GNSS RTK systems by objectively confirming their suitability for specific projects.
• Consistent Documentation: Provides a recognized framework to document and communicate measurement precision and uncertainty.
• Risk Reduction: Minimizes project risks by ensuring GNSS equipment performance limitations are identified and addressed before critical measurements are undertaken.

For anyone relying on GNSS RTK measurement systems in professional practice, ISO 17123-8:2015 bridges the gap between manufacturer specifications and real-world field performance, ensuring measurement reliability and consistency.