Future road applications will require positioning accuracy on the order of one or a few decimeters and a convergence time measured in seconds. A high-accuracy service (HAS) provided by the Global Navigation Satellite System becomes a key enabler to meet these requirements. In particular, the Galileo program has committed to provide a free HAS. This entails several design challenges; namely, to achieve the necessary performance for all users, high-accuracy messages must be optimally formatted, encoded, and broadcast. This article presents an overview of satellite-based HASs and evaluates different transmission schemes based on field and laboratory results, proposing some recommendations for the implementation of an HAS. The article concludes that satellite-based, high-accuracy messages, such as Galileo's, can provide fast convergence and sufficient accuracy worldwide, even in low-visibility environments.

中文翻译：

---

道路应用的高精度卫星信息分析

未来的道路应用将需要一分米或几分米的定位精度和以秒为单位的收敛时间。全球导航卫星系统提供的高精度服务 (HAS) 成为满足这些要求的关键推动因素。特别是，伽利略计划承诺提供免费的 HAS。这带来了一些设计挑战；也就是说，要为所有用户实现必要的性能，必须对高精度消息进行最佳格式化、编码和广播。本文概述了基于卫星的 HAS，并根据现场和实验室结果评估了不同的传输方案，为实施 HAS 提出了一些建议。文章的结论是，基于卫星的高精度信息，例如伽利略的，