NASA’s Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) carries a laser altimeter that fires 10,000 pulses per second towards Earth and records the travel time of individual photons to measure the elevation of the surface below. The volume of data produced by ICESat-2, nearly a TB per day, presents significant challenges for users wishing to efficiently explore the dataset. NASA’s National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC), which is responsible for archiving and distributing ICESat-2 data, provides search and subsetting services on mission data products, but providing interactive data discovery and visualization tools needed to assess data coverage and quality in a given area of interest is outside of NSIDC’s mandate. The OpenAltimetry project, a NASA-funded collaboration between NSIDC, UNAVCO and the University of California San Diego, has developed a web-based cyberinfrastructure platform that allows users to locate, visualize, and download ICESat-2 surface elevation data and photon clouds for any location on Earth, on demand. OpenAltimetry also provides access to elevations and waveforms for ICESat (the predecessor mission to ICESat-2). In addition, OpenAltimetry enables data access via APIs, opening opportunities for rapid access, experimentation, and computation via third party applications like Jupyter notebooks. OpenAltimetry emphasizes ease-of-use for new users and rapid access to entire altimetry datasets for experts and has been successful in meeting the needs of different user groups. In this paper we describe the principles that guided the design and development of the OpenAltimetry platform and provide a high-level overview of the cyberinfrastructure components of the system.

NASA 的冰、云和陆地高程卫星 2 (ICESat-2) 携带激光高度计，每秒向地球发射 10,000 个脉冲，并记录单个光子的传播时间，以测量下方表面的高度。ICESat-2 产生的数据量接近每天 1 TB，这对希望有效探索数据集的用户提出了重大挑战。NASA 的国家冰雪数据中心 (NSIDC) 分布式主动归档中心 (DAAC)，负责归档和分发 ICESat-2 数据，提供任务数据产品的搜索和子集服务，但提供交互式数据发现和可视化工具所需的评估给定感兴趣领域的数据覆盖率和质量超出了 NSIDC 的职责范围。OpenAltimetry 项目是 NASA 资助的 NSIDC 之间的合作项目，UNAVCO 和加州大学圣地亚哥分校开发了一个基于网络的网络基础设施平台，允许用户按需定位、可视化和下载地球上任何位置的 ICESat-2 表面高程数据和光子云。OpenAltimetry 还提供对 ICESat（ICESat-2 的前身任务）的高程和波形的访问。此外，OpenAltimetry 支持通过 API 访问数据，从而为通过 Jupyter 笔记本等第三方应用程序进行快速访问、实验和计算提供机会。OpenAltimetry 强调新用户的易用性和专家对整个测高数据集的快速访问，并成功地满足了不同用户群体的需求。