Open Access on GNSS Permanent Networks Data in Case of Disaster

Earthquakes, as a natural phenomenon causing large physical and social destruction, are the subject of intensive research throughout the world. Spurred by the fact that in year 2020, two catastrophic earthquakes hit Croatia, in March with epicenter near Zagreb and December with epicenter near Petrinja, at the Faculty of Geodesy, University of Zagreb activities were initiated with the aim of strengthening the ability to react in these situations. Focus of those activities is on providing fast, adequate, and complete information on the disaster in the field of geodesy and geoinformatics. The research was focused on interpretation of kinematics of surface motion during the earthquake itself for what high rate permanent GNSS (Global Navigation Satellite System) network stations registrations are necessary. The Croatian earthquakes experience as well as the Mexico (June 2020) and Samosa earthquake (October 2020), pointed out, related to the use of high-rate registration GNSS data, that the primary problem in the use of this data is open access to the data itself. That is why this study has been launched - to gain a global picture of the availability of data from permanent GNSS networks around the world. The research included the collection and processing of information on open access policies for permanent GNSS networks data in the event of natural disasters with an emphasis on earthquakes. A global survey of institutions around the world responsible for managing GNSS permanent networks has been conducted. The survey contains three groups of questions that include general information on the type of permanent networks, models of access to network data and the readiness of countries to reach an international agreement on the opening data of the GNSS network in the event of a disaster. The results indicated that a high percentage of countries participating in the survey were ready to agree to open the data and introduce a common international portal through which scientists and researchers would be able to download GNSS permanent network data free of charge in the event of natural disasters.

地震作为一种会造成严重物理与社会破坏的自然现象，是全球各地开展深入研究的核心课题之一。2020年，克罗地亚接连遭遇两次灾难性地震：3月震中位于萨格勒布附近，12月震中位于佩特林贾附近。受此事件推动，萨格勒布大学大地测量学院启动了相关工作，旨在提升此类灾害情境下的应急响应能力。该类工作的核心目标是在大地测量与地理信息学领域，为灾害事件提供快速、适配且完整的信息支撑。本研究聚焦地震发生过程中的地表运动运动学解译，而这一工作需要依托高采样率永久全球导航卫星系统（Global Navigation Satellite System, GNSS）站网的观测数据。克罗地亚地震，以及2020年6月的墨西哥地震与2020年10月的萨摩萨地震的相关实践经验均表明，高采样率GNSS观测数据应用的首要障碍在于数据本身的开放获取渠道不足。正因如此，本研究得以启动，旨在全面掌握全球范围内永久GNSS站网的数据可获取性现状。研究内容包括收集并处理全球各国针对自然灾害（重点为地震）时的永久GNSS站网数据开放政策相关信息。团队对全球负责管理永久GNSS站网的机构开展了问卷调查，问卷包含三类问题：分别涉及永久站网的基本类型、网络数据的获取模式，以及各国是否愿意就灾害发生时开放GNSS站网数据达成国际统一协议。调查结果显示，参与调研的多数国家均同意开放相关数据，并支持搭建统一的国际门户网站，以便科学家与研究人员在自然灾害发生时可免费下载永久GNSS站网观测数据。