The ILRS: approaching 20 years and planning for the future
The ILRS: approaching 20 years and planning for the future
复制标题
DOI：
10.1007/s00190-019-01241-1
复制
发表时间：
2019-11-01
影响因子：
4.4
通讯作者：
Schreiber, Ulrich
中科院分区：
文献类型：
--
作者：
Pearlman, Michael R.;Noll, Carey E.;Schreiber, Ulrich
国际激光测距服务（ILRS）由国际大地测量学协会（IAG）于1998年建立，旨在支持大地测量学、地球物理学、基本常数和月球研究方面的项目，并为国际地球自转服务提供对维护和改进国际地球参考系（ITRF）至关重要的数据产品，ITRF是地球和地月系统变化的公制测量基础。来自激光测距的其他科学产品包括精确的地面站的地心位置和运动、卫星轨道、地球重力场的组成及其时间变化、地球方向参数、精确的月球星历表和关于月球内部结构的信息。激光测距系统已经在测量到空间中远程光学接收器的单向距离，并在地球和空间的远程地点之间进行非常精确的时间传输。ILRS与IAG的全球大地观测系统密切合作。ILRS开发(1)产品一致性所需的标准和规范，以及(2)最大化网络效率所需的优先级和跟踪策略。该服务收集、合并、分析、存档和分发卫星和月球激光测距数据，以满足各种科学、工程和业务需求，并鼓励新技术的应用，以提高其数据产品的质量、数量和成本效益。ILRS与(1)设计和建造反反射目标的新卫星任务合作，以最大限度地提高数据质量和数量，以及(2)优化科学数据产量的科学计划。自成立以来，ILRS已经发展到包括分布在世界各地的40个激光测距站。ILRS站跟踪从低地球轨道到地球同步轨道高度的90多颗卫星以及月球表面的后向反射器阵列。应用范围已扩大到包括时间传递、远距离目标的异步测距、自由空间量子通信和空间碎片跟踪。激光测距技术正朝着更低能量、更高重复频率（kHz）、单光子敏感探测器、更短的脉冲宽度、更短的正常点间隔（以更快的数据采集）、更多的通道交错、远程访问自动化到自主操作，以及用于实时更新和决策的嵌入式软件的方向发展。给出了Yarragadee站的通道交错示例（见图4）；低轨道卫星的跟踪通常在低轨道卫星和全球导航卫星系统通过的间隙进行。新的卫星阵列提供了更紧凑的目标，并继续为卫星和月球开发更轻、更便宜的阵列。该服务目前提供ITRF业务产品，包括每日/每周的台站位置和每日分辨率的地球方向产品；最近确定了LAGEOS/埃塔龙-1和埃塔龙-2卫星轨道文件每周合并的流程。新产品正在通过目前正在进行的系统错误监测试点项目进行测试。本文将概述该服务中正在进行的活动、目前设想的前进道路以及当前的问题和挑战。
The International Laser Ranging Service (ILRS) was established by the International Association of Geodesy (IAG) in 1998 to support programs in geodesy, geophysics, fundamental constants and lunar research, and to provide the International Earth Rotation Service with data products that are essential to the maintenance and improvement in the International Terrestrial Reference Frame (ITRF), the basis for metric measurements of changes in the Earth and Earth-Moon system. Other scientific products derived from laser ranging include precise geocentric positions and motions of ground stations, satellite orbits, components of Earth's gravity field and their temporal variations, Earth Orientation Parameters, precise lunar ephemerides and information about the internal structure of the Moon. Laser ranging systems are already measuring the one-way distance to remote optical receivers in space and are performing very accurate time transfer between remote sites in the Earth and in Space. The ILRS works closely with the IAG's Global Geodetic Observing System. The ILRS develops (1) the standards and specifications necessary for product consistency, and (2) the priorities and tracking strategies required to maximize network efficiency. The service collects, merges, analyzes, archives and distributes satellite and lunar laser ranging data to satisfy a variety of scientific, engineering, and operational needs and encourages the application of new technologies to enhance the quality, quantity, and cost effectiveness of its data products. The ILRS works with (1) new satellite missions in the design and building of retroreflector targets to maximize data quality and quantity, and (2) science programs to optimize scientific data yield. Since its inception, the ILRS has grown to include forty laser ranging stations distributed around the world. The ILRS stations track more than ninety satellites from low Earth orbit (LEO) to the geosynchronous orbit altitude as well as retroreflector arrays on the surface of the Moon. Applications have been expanded to include time transfer, asynchronous ranging for targets at extended ranges, free space quantum telecommunications, and the tracking of space debris. Laser ranging technology is moving to lower energy, higher repetition rates (kHz), single-photon-sensitive detectors, shorter pulse widths, shorter normal point intervals for faster data acquisition, and increased pass interleaving, automated to autonomous operation with remote access, and embedded software for real-time updates and decision making. An example of pass interleaving is presented for the Yarragadee station (see Fig. 4); tracking of LEO satellites is often accommodated during break in LEO and GNSS passes. New satellites arrays provide more compact targets and work continues on the development of lighter less expensive arrays for satellites and the moon. The service now provides operational ITRF products including daily/weekly station positions and daily resolution Earth orientation products; the flow of weekly combination of satellite orbit files for LAGEOS/Etalon-1 and -2 has recently been established. New products are under testing through a pilot project on systematic error monitoring currently underway. The article will give an overview of activities underway within the service, paths forward presently envisioned, and current issues and challenges.