Quasi‐thermal noise (QTN) spectroscopy has been extensively used as an accurate tool to measure electron density and temperature in space plasmas. If the antenna length to radius ratio is sufficiently large, a typical measured spectrum clearly shows a resonance at the electron plasma frequency and a lower frequency plateau that quantify the electron distributions. The Wind spacecraft, with its long, thin antennas, is considered the mission par excellence for the implementation of the QTN method. However, a major issue in applying QTN spectroscopy is contamination from signals other than the ubiquitous plasma noise in the vicinity of plasma frequency, affecting the measured spectra and confusing their physical interpretation. In this work, we present a new method for selecting the observations of uncontaminated QTN, distinguishing it from other plasma and spacecraft effects. The selected measurements are used to obtain accurate values for both thermal and suprathermal electron parameters. Testing of the method on 1.5M observations under various conditions in the solar wind, including slow and fast wind and solar transients, confirms the reliability and accuracy of the method with no systematic flaws.

中文翻译：

---

准热噪声谱法确定航天器太阳风电子参数

准热噪声（QTN）光谱已被广泛用作测量空间等离子体中电子密度和温度的精确工具。如果天线的长度与半径之比足够大，则典型的测量频谱将清楚地显示出在电子等离子体频率和较低的平稳频率上的共振，该共振频率量化了电子分布。带有细长天线的“风”飞船被认为是实施QTN方法的卓越任务。但是，应用QTN光谱法的一个主要问题是来自等离子频率附近普遍存在的等离子噪声以外的信号污染，从而影响了所测量的光谱并混淆了其物理解释。在这项工作中，我们提出了一种选择未污染QTN观测值的新方法，区别于其他等离子体和航天器的影响。所选的测量用于获取热和超热电子参数的准确值。在太阳风的各种条件下，包括慢速和快速风以及太阳瞬变，在1.5M观测条件下对该方法进行测试，证实了该方法的可靠性和准确性，没有系统性缺陷。