Welcome to the Spring 2021 issue of NAVIGATION. We present the latest research articles (papers) that have successfully completed the thorough review process managed by our associate editors and their expert reviewers. The topics span the broad range of PNT research from GNSS interference mitigation to better positioning of low Earth orbit satellites. And we feature an article on ION's GNSS software‐defined radio (SDR) metadata standard, which was adopted by the institute in January 2020. This standard will simplify the exchange of datasets between groups and promote the interoperability of satnav SDR systems. Here in “Navigator Notes,” in addition to highlighting the latest video abstracts of articles published in the journal and the most recent ION webinars, we announce the ION 2020 Samuel M. Burka Award winners and the five most downloaded NAVIGATION articles in 2020.

欢迎阅读《NAVIGATION》 2021年春季刊。我们介绍了最新的研究文章（论文），这些文章成功地完成了由我们的副编辑及其专家审稿人管理的彻底的审阅过程。这些主题涵盖了从GNSS缓解干扰到低地球轨道卫星更好定位的PNT研究的广泛范围。我们还将重点介绍ION的GNSS软件定义的无线电（SDR）元数据标准，该机构于2020年1月采用了该标准。该标准将简化组之间的数据集交换，并促进卫星导航SDR系统的互操作性。在“导航说明”中，除了突出显示该杂志上发布的文章的最新视频摘要以及最新的ION网络研讨会外，我们还宣布ION 2020塞缪尔·布尔卡奖和五个下载量最大的NAVIGATION 2020年的文章。