Global Navigation Satellite System (GNSS) IGS Final Analysis Center (AC) Clock Solution Product (daily files, generated weekly) from NASA CDDIS

This derived product set consists of Global Navigation Satellite System Final Satellite and Receiver Clock Product (30-second granularity, daily files, generated weekly) from the NASA Crustal Dynamics Data Information System (CDDIS). GNSS provide autonomous geo-spatial positioning with global coverage. GNSS data sets from ground receivers at the CDDIS consist primarily of the data from the U.S. Global Positioning System (GPS) and the Russian GLObal NAvigation Satellite System (GLONASS). Since 2011, the CDDIS GNSS archive includes data from other GNSS (Europe’s Galileo, China’s Beidou, Japan’s Quasi-Zenith Satellite System/QZSS, the Indian Regional Navigation Satellite System/IRNSS, and worldwide Satellite Based Augmentation Systems/SBASs), which are similar to the U.S. GPS in terms of the satellite constellation, orbits, and signal structure. Analysis Centers (ACs) of the International GNSS Service (IGS) retrieve GNSS data on regular schedules to produce GNSS satellite and ground receiver clock values. The IGS Analysis Center Coordinator (ACC) uses these individual AC solutions to generate the official IGS final combined satellite and receiver clock products. The AC clock products consist of daily station and satellite clock solution files, generated on a weekly basis with a delay of approximately 10 days (from the last day of the week). All satellite and receiver clock solution files utilize the clock RINEX format and span 24 hours from 00:00 to 23:45 UTC.

本衍生数据集集合包含来自美国国家航空航天局（National Aeronautics and Space Administration，NASA）地壳动力学数据信息系统（Crustal Dynamics Data Information System，CDDIS）的全球导航卫星系统（Global Navigation Satellite System，GNSS）最终卫星与接收机钟差产品（时间粒度为30秒，以每日文件形式存储，每周生成更新）。全球导航卫星系统可实现全球覆盖的自主地理空间定位。CDDIS收录的地面接收机GNSS数据集最初主要包含美国全球定位系统（Global Positioning System，GPS）与俄罗斯全球导航卫星系统（GLObal NAvigation Satellite System，GLONASS）的数据。自2011年起，CDDIS的GNSS档案库新增了其他GNSS系统数据：包括欧洲伽利略系统、中国北斗系统、日本准天顶卫星系统（Quasi-Zenith Satellite System，QZSS）、印度区域导航卫星系统（Indian Regional Navigation Satellite System，IRNSS）以及全球星基增强系统（Satellite Based Augmentation Systems，SBAS），上述系统在卫星星座、轨道与信号结构方面均与美国GPS相似。国际GNSS服务（International GNSS Service，IGS）的分析中心（Analysis Centers，ACs）会按固定周期获取GNSS数据，以生成GNSS卫星与地面接收机的钟差参数。IGS分析中心协调机构（Analysis Center Coordinator，ACC）会整合各分析中心的独立解算结果，生成官方的IGS最终组合式卫星与接收机钟差产品。分析中心的钟差产品为每日测站与卫星钟差解算文件，每周生成，生成延迟约为10天（以当周最后一天为起始计算）。所有卫星与接收机钟差解算文件均采用钟差RINEX格式，时间覆盖协调世界时00:00至23:45，跨度为24小时。