This document provides requirements and recommendation for space-based systems that, using satellite radionavigation services, provide high accuracy positioning of rovers. It is particularly intended for rovers whose operation requires meeting specific safety requirements, including in situations of low visibility. This document also provides methods to verify the system requirements, as well as complementary information on particular applications (Annex A), mobile mapping systems (Annex B) and augmented positioning (Annexes C and D).st edition 2021-07 Space systems — Space-based services for a high accuracy positioning system with safety requirements Reference number ISO/TS 22591:2021(E) ？ ISO 2021 ISO/TS 22591:2021(E) COPYRIGHT PROTECTED DOCUMENT ？ ISO 2021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publicat