A review of researches related to ultra low frequency (ULF) waves studied using a midlatitude coherent decameter radar located near Ekaterinburg (EKB), Russia is presented. The radar was constructed similar to SuperDARN radars. During the experiment conducted in 2013–2015 three of its beams were surveyed successively with the integration time of 6 s providing time resolution of 18 s at each beam. In a few cases, data received in the nighttime ionosphere showed signatures of the drift compressional mode. In one of them, the wave exhibited clear dependence of frequency on azimuthal wave number $m$, which corresponds with the theory of drift compressional waves. In another case, merging of the drift compressional and Alfvén modes at some critical value of $m$ was shown. A number of the observed waves’ frequencies were compared with the Alfvén ones inferred from the spacecraft data. The results showed that in a large part of cases waves had sub-Alfvénic frequencies. This finding complies with the assumption that at least a part of the waves observed with the radar should be identified with the drift compressional mode, whose frequency can be lower than frequency of field line resonance (FLR). Additionally, a case of simultaneous spacecraft and radar wave observation was presented. As the wave had poloidal structure, diamagnetic properties, and its frequency was considerably lower than the minimal frequency of the FLR, it was assumed that it was some kind of compressional mode, apparently the drift compressional wave.

介绍了与使用位于俄罗斯叶卡捷琳堡 (EKB) 附近的中纬度相干十米雷达研究的超低频 (ULF) 波相关的研究综述。该雷达的构造类似于 SuperDARN 雷达。在 2013-2015 年进行的实验期间，它的三个光束被连续测量，积分时间为 6 秒，每个光束的时间分辨率为 18 秒。在少数情况下，夜间电离层接收到的数据显示了漂移压缩模式的特征。其中之一，波表现出明显的频率依赖于方位角波数$米$，这与漂移压缩波理论相对应。在另一种情况下，在某些临界值处合并漂移压缩和阿尔文模式$米$被显示。许多观测到的波的频率与从航天器数据中推断出的阿尔芬波的频率进行了比较。结果表明，在大部分情况下，波具有亚阿尔芬频率。这一发现符合这样的假设，即雷达观测到的波中至少有一部分应该被识别为漂移压缩模式，其频率可能低于场线共振 (FLR) 的频率。此外，还介绍了一个同时进行航天器和雷达波观测的案例。由于该波具有极向结构、抗磁特性，并且其频率远低于 FLR 的最小频率，因此假设它是某种压缩模式，显然是漂移压缩波。