local hour angle

简明释义

地方时角)

英英释义

例句

1.To find the local time of sunset, we need to consider the local hour angle of the sun.

要找到日落的当地时间，我们需要考虑太阳的地方时角。

2.The astronomer calculated the local hour angle to determine the position of the star in the sky.

天文学家计算了地方时角以确定星星在天空中的位置。

3.The formula for calculating the local hour angle involves the observer's longitude.

计算地方时角的公式涉及观察者的经度。

4.During the astronomy lecture, the professor explained the significance of the local hour angle in celestial mechanics.

在天文学讲座中，教授解释了地方时角在天体力学中的重要性。

5.In navigation, the local hour angle helps sailors determine their longitude.

在导航中，地方时角帮助水手确定他们的经度。

作文

The concept of local hour angle is essential in the field of astronomy and navigation. It refers to the angle that represents the time since a celestial object, such as a star or the sun, has crossed the observer's local meridian. Understanding this concept is crucial for astronomers and navigators alike, as it helps them determine the position of celestial bodies in the sky at any given time.To grasp the significance of local hour angle, one must first understand how time is measured in relation to the Earth's rotation. The Earth rotates 360 degrees in approximately 24 hours, which means it rotates about 15 degrees every hour. Thus, when we talk about the local hour angle of a celestial body, we are essentially discussing how far that body is from the local meridian, measured in degrees. For example, if the sun is directly overhead at noon, its local hour angle is 0 degrees. As the day progresses and the sun moves across the sky, its local hour angle increases. By the time it reaches 3 PM, the sun will have moved 45 degrees west of the local meridian, resulting in a local hour angle of 45 degrees. Conversely, in the morning, before noon, the local hour angle would be negative, indicating that the sun is east of the local meridian.This measurement is not only important for understanding the position of the sun but also for other celestial objects. For instance, astronomers use the local hour angle to track stars and planets throughout the night sky. By knowing the local hour angle of a particular star, they can predict when it will rise or set relative to the observer's location. This knowledge is particularly useful for stargazers and amateur astronomers who want to observe specific celestial events.Moreover, the local hour angle plays a vital role in celestial navigation. Navigators use this concept to determine their position on Earth based on the positions of stars. By measuring the local hour angle of a known star at a specific time, navigators can calculate their latitude and longitude, enabling them to navigate accurately across oceans and vast distances.In summary, the local hour angle is a fundamental concept in both astronomy and navigation. It provides a way to measure the position of celestial bodies relative to the observer's local meridian, facilitating the tracking of these objects across the sky. Whether one is an experienced astronomer or a novice stargazer, understanding the local hour angle is key to unlocking the mysteries of the night sky. As we continue to explore the universe, this concept will remain an indispensable tool for those seeking to comprehend the celestial mechanics that govern our world.

“地方时角”这一概念在天文学和导航领域中至关重要。它指的是自某个天体（如恒星或太阳）越过观察者的地方子午线以来的时间角度。理解这一概念对天文学家和导航员来说都至关重要，因为它帮助他们确定任何给定时间天空中天体的位置。要掌握“地方时角”的重要性，首先必须了解与地球自转相关的时间测量方式。地球在大约24小时内旋转360度，这意味着它每小时旋转约15度。因此，当我们谈论某个天体的“地方时角”时，实际上是在讨论该天体距离地方子午线的角度，以度为单位进行测量。例如，如果太阳在中午正好在头顶上，那么它的“地方时角”就是0度。随着时间的推移，太阳在天空中移动，它的“地方时角”会增加。当太阳到达下午3点时，它将向西移动45度，导致其“地方时角”为45度。相反，在早晨中午之前，“地方时角”将是负值，表示太阳位于地方子午线的东侧。这一测量不仅对于理解太阳的位置很重要，还适用于其他天体。例如，天文学家使用“地方时角”来跟踪夜空中的星星和行星。通过知道特定星星的“地方时角”，他们可以预测它何时会相对于观察者的位置升起或落下。这一知识对想要观察特定天文事件的星空爱好者和业余天文学家尤其有用。此外，“地方时角”在天文导航中也发挥着至关重要的作用。导航员利用这一概念根据星星的位置来确定他们在地球上的位置。通过在特定时间测量已知星星的“地方时角”，导航员可以计算出他们的纬度和经度，从而使他们能够在海洋和广阔的距离上准确导航。总之，“地方时角”是天文学和导航中的一个基本概念。它提供了一种测量天体相对于观察者地方子午线位置的方法，便于跟踪这些物体在天空中的移动。无论是经验丰富的天文学家还是初学者，理解“地方时角”都是解锁夜空奥秘的关键。随着我们继续探索宇宙，这一概念将仍然是那些寻求理解支配我们世界的天体力学的重要工具。