maximum useful frequency

简明释义

最大使用频率最高使用频率

英英释义

例句

1.Engineers must calculate the maximum useful frequency 最大有效频率 to ensure that radar systems operate efficiently.

工程师必须计算最大有效频率 maximum useful frequency以确保雷达系统高效运行。

2.In radio communication, the choice of frequency is crucial; operators often refer to the maximum useful frequency 最大有效频率 to optimize their signals.

在无线电通信中，频率的选择至关重要；操作员通常参考最大有效频率 maximum useful frequency来优化他们的信号。

3.For emergency services, knowing the maximum useful frequency 最大有效频率 is essential for reliable communication.

对于紧急服务而言，了解最大有效频率 maximum useful frequency对可靠通信至关重要。

4.The maximum useful frequency 最大有效频率 determines how far a signal can travel before it loses integrity.

在信号失去完整性之前，最大有效频率 maximum useful frequency决定了信号可以传播的距离。

5.During the summer months, the maximum useful frequency 最大有效频率 for HF communications can change significantly due to ionospheric conditions.

在夏季，由于电离层条件的变化，HF通信的最大有效频率 maximum useful frequency可能会显著变化。

作文

In the realm of radio communications, understanding the concept of maximum useful frequency is crucial for both amateur and professional operators. The maximum useful frequency (often abbreviated as MUF) refers to the highest frequency at which a radio wave can be transmitted and still be effectively received over a specific distance during a given period. This frequency is not constant; it varies depending on several factors, including the time of day, solar activity, and the specific propagation characteristics of the ionosphere. The ionosphere is a layer of the Earth's atmosphere that is ionized by solar and cosmic radiation. It plays a significant role in radio wave propagation, particularly for high-frequency (HF) communications. At certain times, the ionosphere reflects radio waves back to Earth, allowing them to travel beyond the horizon. However, this reflection is frequency-dependent, meaning that there is a point beyond which higher frequencies will not be reflected and will instead pass through the ionosphere into space. This point is defined as the maximum useful frequency. For example, during the day, the MUF tends to be higher due to increased solar radiation, which ionizes the ionosphere more effectively. Conversely, at night, the MUF decreases because the ionization levels drop, limiting the frequencies that can be used for long-distance communication. Understanding these variations allows operators to select the appropriate frequencies for their transmissions, ensuring that their signals are effectively received by distant stations.In practical terms, knowing the maximum useful frequency can significantly enhance communication efficiency. For instance, if an operator attempts to use a frequency above the MUF, their signal may become weak or entirely lost, leading to frustration and ineffective communication. On the other hand, staying within the limits of the MUF ensures that the signal is strong and clear, facilitating successful exchanges of information.Moreover, the maximum useful frequency is not solely determined by the ionosphere; it is also influenced by geographic location, season, and atmospheric conditions. For example, in regions closer to the equator, the MUF may be higher compared to polar regions, where the ionosphere behaves differently due to variations in solar radiation exposure. Additionally, during periods of increased solar activity, such as solar flares, the MUF can experience sudden changes, impacting communication reliability.In conclusion, the maximum useful frequency is a vital concept in radio communications that determines the highest effective frequency for transmission over a given distance. By understanding and utilizing the MUF, operators can optimize their communication strategies, ensuring that their signals reach their intended recipients. As technology continues to advance and our understanding of atmospheric science deepens, the implications of the MUF will only grow, highlighting the importance of this concept in the field of telecommunications. Whether for personal use or professional applications, mastering the maximum useful frequency is essential for anyone involved in radio communications.

在无线电通信领域，理解“最大有效频率”这一概念对业余和专业操作员来说都是至关重要的。“最大有效频率”（通常缩写为MUF）是指在特定距离内，在给定时间内可以有效接收的最高传输频率。这个频率并不是恒定不变的；它会因多个因素而变化，包括一天中的时间、太阳活动以及电离层的具体传播特性。电离层是地球大气层的一部分，受到太阳和宇宙辐射的电离。它在无线电波传播中扮演着重要角色，特别是在高频（HF）通信中。在某些时段，电离层会将无线电波反射回地球，使其能够超越地平线进行传播。然而，这种反射是频率依赖的，这意味着存在一个临界点，高于该频率的无线电波将无法被反射，而是穿透电离层进入太空。这个点被定义为“最大有效频率”。例如，在白天，由于太阳辐射增加，电离层的电离效能更强，因此MUF往往较高。相反，在夜间，由于电离水平下降，MUF降低，从而限制了可以用于远程通信的频率。理解这些变化使得操作员能够选择适当的传输频率，确保他们的信号能够有效地被远方的站点接收。在实际应用中，了解“最大有效频率”可以显著提高通信效率。例如，如果操作员尝试使用超过MUF的频率，他们的信号可能会变得微弱或完全丢失，导致沮丧和无效的通信。另一方面，保持在MUF的限制内可以确保信号强大且清晰，从而促进信息的成功交流。此外，“最大有效频率”不仅仅受电离层的影响；它还受到地理位置、季节和气象条件的影响。例如，在靠近赤道的地区，MUF可能会比极地地区更高，因为极地地区由于太阳辐射暴露的变化，电离层的表现有所不同。此外，在太阳活动增强的时期，例如太阳耀斑，MUF可能会经历突然变化，影响通信的可靠性。总之，“最大有效频率”是无线电通信中的一个重要概念，它决定了在给定距离内有效传输的最高频率。通过理解和利用MUF，操作员可以优化他们的通信策略，确保他们的信号到达预定接收者。随着技术的不断进步和我们对大气科学理解的加深，MUF的影响只会增大，突出这一概念在电信领域的重要性。无论是个人使用还是专业应用，掌握“最大有效频率”对于任何参与无线电通信的人都是必不可少的。