Abstract. The purpose of these historical notes is to present the early history of the Jicamarca Radio Observatory (JRO), a research facility that has been conducting observations and studies of the equatorial ionosphere for more than 50 years. We have limited the scope of these notes to the period of the construction of the observatory and roughly the first decade of its operation. Specifically, this period corresponds to the directorships under Kenneth Bowles, Donald Farley, and Tor Hagfors and the first period of Ronald Woodman, i.e., the years between 1960 and 1974. Within this time frame, we will emphasize observational and instrumental developments which led to define the capabilities of the Jicamarca incoherent scatter (IS) radar to measure the different physical parameters of the ionosphere. At the same time, we partially cover the early history of the IS technique which has been used by many other observatories built since. We will also briefly mention the observatory's early and most important contributions to our understanding of the physical mechanisms behind the many peculiar phenomena that occur at the magnetic Equator. Finally, we will put special emphasis on the important developments of the instrument and its observing techniques that frame the capabilities of the radar at that time.

中文翻译：

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贾卡马卡天文台的早期历史和不相干散射技术

摘要。这些历史记录的目的是介绍吉卡马卡射电天文台（JRO）的早期历史，该研究机构一直在进行赤道电离层的观测和研究50多年。我们将这些注释的范围限制在天文台的建设时期及其大致运行的最初十年。具体来说，这一时期对应于肯尼斯·鲍尔斯（Kenneth Bowles），唐纳德·法利（Donald Farley）和托·哈格福斯（Tor Hagfors）以及罗纳德·伍德曼（Ronald Woodman）的第一时期，即1960年至1974年之间的董事职位。在此时间范围内，我们将着重观察和仪器发展，定义Jicamarca非相干散射（IS）雷达测量电离层不同物理参数的能力。与此同时，我们将部分介绍IS技术的早期历史，此技术已被此后建立的许多其他观测所使用。我们还将简要提及天文台对我们理解磁赤道出现的许多奇特现象背后的物理机制的早期和最重要的贡献。最后，我们将特别强调该仪器的重要发展及其构成当时雷达能力的观测技术。