Standards Development

Scope

This GNSS metrology document aims to provide a methodological reference framework for assessing the performance of GNSS based positioning terminals (GBPT) using GNSS (Global Navigation Satellite Systems) technology. In this document, the GBPT is specifically used for various types of vehicles—such as cars, drones, trains, and ships—and not for any timing-related applications.

This document is the first part of the ISO 25082 series, specifically developed to structure interactions with clients within the context of test engineering activities. It sets precise conditions for receiving client requests and presenting test results, thereby ensuring clear, effective communication that meets the expectations of both parties.

Please see draft for Figure 1 — Place of the standard within the V-model conceptualization of the key stages in test engineering

The document defines and characterizes specific operational needs, then translates them into technical requirements, thereby forming a solid foundation for designing relevant and representative test scenarios for various use cases. The approach ensures that the systems tested not only meet operational expectations but also fulfill the desired functionalities for their intended applications.

To ensure alignment between requirements and actual performance, the fundamental principle of an assessment is based on measuring the deviations between a reference trajectory, considered ideal but subject to measurement uncertainties, and the trajectories recorded by the Device Under Test (GBPT) to a representative scenario. This comparison process methodically quantifies key parameters such as the accuracy, availability, and reliability of GBPT, taking into account the diverse environmental and operational conditions they may face.

In this context, the metrics commonly used to define performance are systematically identified, defined, and classified by their features. These metrics include positioning, velocity, and attitude errors, as well as indicators such as service continuity and availability, performance over time, and data reliability. Each of these metrics can play a critical role in evaluating the overall performance of a GNSS Based Positioning Terminal (GBPT) across varied and sometimes complex scenarios.

These same metrics also serve as the basis for defining performance classes to be applied to establish a declaration of compliance. By structuring performance assessments around these indicators, it is possible to ensure that the obtained results meet normative requirements and align with the expectations of clients and certification authorities.

Furthermore, this document defines the minimum requirements to consider before selecting the most appropriate testing method from a metrological perspective. The goal is to choose an approach that ensures the validity and reliability of measurements. In addition to their representativeness, the results are repeatable and reproducible from one test to another for the same GBPT and scenario. This methodological rigor is essential for obtaining consistent and comparable data.

For the test results are presented in a structured manner to meet the client's expectations, especially in cases where the results shall comply with type certification requirements. Clarity, precision, and rigor in presenting the measured performance are indispensable to ensure that a GNSS Based Positioning Terminal meets the standards and regulations in effect.

Finally, this document is primarily aimed at accredited testing laboratories responsible for applying it within the scope of their engineering testing services. It defines the minimum requirements needed to ensure clear and effective communication with fitness-for-purpose-based clients and stakeholders. By rigorously applying these requirements, any organization seeking to plan GNSS tests can optimize the efficiency of its processes while ensuring the production of reliable and accurate results.