Ocean Surface Topography Mission (OSTM) /Jason-2: Orbital Information (NODC Accession 0044985)

This accession contains the descriptions for the OSTM/Jason-2 orbital information, which is served through the NOAA/NESDIS Comprehensive Large Array-data Stewardship System (CLASS): http://www.class.noaa.gov

OSTM/Jason-2 is a follow-on mission to Jason-1, which takes over and continues the TOPEX/Poseidon and Jason-1 missions. OSTM/Jason-2 involves Centre National d'Etudes Spatiales (CNES), NASA and 2 new partners: the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and NOAA in order to 1) ensure continuity of high quality measurements for ocean science, and 2) provide operational products for assimilation and forecasting applications. OSTM/Jason-2 was launched on 20 June 2008 and reached its nominal repetitive orbit on 4 July 2008. The start of cycle 1 occurred on 12 July 2008.

These files are produced by CNES for offline (IGDR, GDR) data production. For GPSP1, intermediate level-1 data files are in "RINEX" format and from the Global Positioning System (GPS) receiver and are used to compute precise GPS orbits for the spacecraft. For TLE: Two Line Element files are used to determine the position and velocity of the satellite. Within CLASS, they will be used directly to determine each orbit's equator crossing longitude and time which subsequently are used to support spatial search. For MOE and POE, medium-precision and precision orbital ephemeris files are from the DORIS system. All members of the Orbital Information family were made unrestricted on 15 December, 2008.

Other data/products associated with OSTM/Jason-2 are also provided through CLASS. They are: Level-2 Geophysical Data Records (GDRs), ancillary and auxiliary data files used to generate Level-2 products, quality reports from the near real-time altimetry validation system (NRTAVS) and telemetry data. The descriptions of these data products can also be accessed in other accessions at NODC.

本存档包含OSTM/Jason-2轨道信息的相关说明，该数据通过美国国家海洋和大气管理局/国家环境卫星、数据与信息服务中心综合大型数据管理系统（NOAA/NESDIS Comprehensive Large Array-data Stewardship System, CLASS）提供服务，访问链接为：http://www.class.noaa.gov

OSTM/Jason-2是Jason-1的后续任务，承接并延续了TOPEX/Poseidon与Jason-1两项任务的观测工作。该任务由法国国家空间研究中心（Centre National d'Etudes Spatiales, CNES）、美国国家航空航天局（National Aeronautics and Space Administration, NASA），以及两家新合作伙伴——欧洲气象卫星开发组织（European Organisation for the Exploitation of Meteorological Satellites, EUMETSAT）与美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）联合实施，旨在达成两大目标：1）为海洋科学研究提供高质量测量数据的连续性保障；2）为数据同化与预报应用提供业务化产品。OSTM/Jason-2于2008年6月20日发射升空，并于2008年7月4日进入标准重复轨道任务状态，首个任务周期于2008年7月12日启动。

此类文件由法国国家空间研究中心（CNES）制作，用于离线（IGDR、GDR）数据生产。针对GPSP1数据：一级中间数据文件采用RINEX格式（RINEX），源自全球定位系统（Global Positioning System, GPS）接收机，用于计算航天器的精密GPS轨道。针对TLE数据：两行轨道根数（Two Line Element, TLE）文件用于确定卫星的位置与速度，在CLASS系统中将直接用于计算每条轨道的赤道穿越经度与时刻，后续将用于支持空间检索服务。针对MOE与POE数据：中精度与精密轨道星历文件源自DORIS系统。所有轨道信息系列数据集均于2008年12月15日开放全量访问权限。

其他与OSTM/Jason-2相关的数据/产品也通过CLASS系统提供，具体包括：二级地球物理数据记录（Geophysical Data Records, GDRs）、用于生成二级产品的辅助数据文件、近实时测高验证系统（Near Real-Time Altimetry Validation System, NRTAVS）生成的质量报告，以及遥测数据。上述数据产品的说明文档也可在国家海洋数据中心（National Oceanographic Data Center, NODC）的其他存档中获取。