We outline the construction of a refined version of the New Luyten Two-Tenths (NLTT) catalog of high proper motion stars, which will contain improved astrometry and photometry for the vast majority of the ~59,000 stars in NLTT. The bright end is constructed by matching NLTT stars to Hipparcos, Tycho-2, and Starnet; the faint end by matching to USNO-A and the Two Micron All Sky Survey (2MASS). In this first paper, we detail the bright-end matching procedure. We show that for the majority of stars in his catalog, Luyten measured positions accurate to 1'' even though he recorded his results much more coarsely. However, there is a long tail of position errors, with one error as large as 11°. Proper-motion errors for the stars with small position errors are 24 mas yr-1 (1 σ) but deteriorate to 34 mas yr-1 for stars with inferior positions. NLTT is virtually 100% complete for V 11.5 and |b| 15°, but completeness in this magnitude range falls to ~75% at the Galactic plane. Incompleteness near the plane is not uniform, but is rather concentrated in the interval -80° l 20°, where the Milky Way is brightest.
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机译：我们概述了新的Luyten二十分之星（NLTT）的高适速运动星表的精简版本的构建，该目录将为NLTT的约59,000颗恒星中的绝大部分提供改进的天文测量和光度法。通过将NLTT恒星匹配到Hipparcos，Tycho-2和Starnet来构造明亮的一端。通过匹配USNO-A和“两微米全天候测量”（2MASS），获得了微弱的效果。在第一篇论文中，我们详细介绍了亮端匹配过程。我们显示，对于Luyten对他目录中的大多数恒星来说，即使他记录的结果要粗糙得多，其位置也精确到1英寸。但是，位置误差的尾巴很长，一个误差高达11°。位置误差较小的恒星的正常运动误差为24 mas yr-1（1σ），但位置较差的恒星的运动误差为34 mas yr-1。对于V 11.5和| b |，NLTT实际上是100％完整的。 > 15°，但在银河平面上，此量级范围内的完整性下降到〜75％。靠近平面的不完整度不是均匀的，而是集中在-80°展开▼
