VHF Radar Observations of Mid-latitude Sporadic-E and Spread-F at Damp Santiago, Puerto Rico

调查人员将使用位于波多黎各的两个甚高频（VHF）雷达系统搜索电离层中纬度的不规则现象。这些不规则现象在赤道地区相当普遍，但直到最近才在中纬度地区观察到。这些早期的探测并没有以一套全面的测量为特征，科学家们可以通过这些测量来研究这些不规则现象的来源和演变。由于去年在波多黎各部署了两个甚高频雷达系统，以支持美国宇航局的火箭运动，因此使用各种不同的观测仪器观察中纬度的不规则现象是一个独特的机会。尤其重要的是阿雷西博非相干散射雷达，其视场与甚高频雷达的视场大致一致。阿雷西博雷达是世界上最灵敏的非相干散射雷达，提供了研究环境电子密度、离子和电子温度的手段，在这些条件下，不规则现象会形成。大多数时候，阿雷西博的1000英尺天线用于射电天文观测，但研究人员在1999年获得了观测时间，以便与甚高频雷达进行协调测量。这一独特的数据集可用于研究中纬度散发E和传播F的起源和演变，这两种病毒都可能对导航和通信系统产生有害影响。

The investigators will search for mid-latitude irregularities in the ionosphere using two very high frequency (VHF) radar systems located in Puerto Rico. These irregularities are fairly common in the equatorial regions, but have only recently been observed at mid-latitudes. These earlier detections did not feature a comprehensive set of measurements by which scientists could study the source and evolution of the irregularities. Because two VHF radar systems were deployed in Puerto Rico last year to support a NASA rocket campaign, there is a unique opportunity to observe mid-latitude irregularities using a variety of different observing instruments. Especially important is the Arecibo incoherent scatter radar whose field of view roughly coincides with that of the VHF radars. The Arecibo radar is the world's most sensitive incoherent scatter radar, offering the means to study the ambient electron density and ion and electron temperatures within which the irregularities form. Most of the time, the 1000 ft antenna at Arecibo is used for radio astronomical observations, but the investigators have acquired observing time during 1999 to make the coordinated measurements with the VHF radars. This unique data set can be used to study the origin and evolution of mid-latitude sporadic E and spread F, both of which can potentially have deleterious effects on navigation and communication systems.