标题： 改进OCARS目录中的源位置：一种初步方法 显示英文标题

标题： Improving source positions in the OCARS catalog: A first approach

摘要： OCARS（光学特性天文测量射电源）是一个综合的目录，包含与通过甚长基线干涉测量（VLBI）观测确定其坐标的天文测量射电源相关的各种附加数据。它包含了源坐标、目标类型、红移、光学和近红外星等信息。 直到现在，OCARS源的坐标仅仅是直接从输入目录复制过来的，因此系统性地表现出不均匀性。 这项工作首次尝试获取一组统一的无线电波源坐标，这些坐标已调整至国际天球参考框架（ICRF），更具体地说是第三个ICRF版本，即ICRF3。 将截至2024年12月的旧版OCARS源坐标和截至2025年3月的新版OCARS源坐标与ICRF3-SX目录中的源坐标进行比较，使用矢量球谐函数（VSH）技术显示，新OCARS位置相对于ICRF3框架的系统误差几乎完全消除。 显示英文摘要

摘要： OCARS (Optical Characteristics of Astrometric Radio Sources) is a compiled catalog of various additional data associated with astrometric radio sources whose coordinates have been determined from very long baseline interferometry (VLBI) observations. It contains source coordinates, object type, redshift, optical and near-infrared magnitudes. Until now, OCARS source coordinates were simply copied from input catalogs and, as a result, were systematically inhomogeneous. This work is the first attempt to obtain a unified set of radio source coordinates aligned to the International Celestial Reference Frame (ICRF), more specically to the third ICRF release, ICRF3. Comparison of the source coordinates in the old OCARS version as of December 2024 and the new OCARS version as of March 2025 with the ICRF3-SX catalog using the vector spherical harmonics (VSH) technique showed almost complete elimination of systematic errors in new OCARS positions relative to the ICRF3 frame.