We carry out analyses of some parameters of the galactic spiral arms, in the currently available samples. We present a catalog of the observed pitch angle for each spiral arm in the Milky Way disk. For each long spiral arm in the Milky Way, we investigate for each individual arm its pitch angle, as measured through different methods (parallaxes, twin-tangent arm, kinematical, etc), and assess their answers. Second, we catalog recent advances in the cartography of the Galaxy (global mean arm pitch, arm number, arm shape, interarm distance at the Sun). We statistically compare the results over a long time frame, from 1980 to 2017. Histograms of about 90 individual results published in recent years (since mid-2015) are compared to 66 earlier results (from 1980 to 2005), showing the ratio of primary to secondary peaks to have increased by almost a factor of 3. Similarly, many earlier discrepancies (expressed in r.m.s.) have been reduced by almost a factor 3.

中文翻译：

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约束银河系中星系旋臂的俯仰角

我们在当前可用的样本中对银河旋臂的一些参数进行了分析。我们提供了银河系盘中每个螺旋臂观测到的俯仰角的目录。对于银河系中的每条长螺旋臂，我们调查每条螺旋臂的俯仰角，通过不同的方法（视差、双切臂、运动学等）测量，并评估它们的答案。其次，我们编目了银河系制图的最新进展（全球平均臂距、臂数、臂形状、太阳臂间距离）。我们从 1980 年到 2017 年的很长一段时间内对结果进行了统计比较。 近年来（自 2015 年年中以来）发表的大约 90 个个人结果的直方图与 66 个早期结果（从 1980 年到 2005 年）进行了比较，