Greenwich hour angle

简明释义

格林尼治时角

英英释义

例句

1.In celestial navigation, understanding the Greenwich hour angle (格林威治时角) helps sailors calculate their longitude.

在天体导航中，理解Greenwich hour angle（格林威治时角）有助于水手计算他们的经度。

2.The Greenwich hour angle (格林威治时角) is essential for accurately determining the time of sunset in various locations.

准确确定不同地点日落时间的关键是Greenwich hour angle（格林威治时角）。

3.Navigators use the Greenwich hour angle (格林威治时角) to adjust their course when sailing across different time zones.

航海者使用Greenwich hour angle（格林威治时角）在穿越不同的时区时调整航向。

4.To find the local time, astronomers convert the Greenwich hour angle (格林威治时角) of the sun into hours.

为了找到当地时间，天文学家将太阳的Greenwich hour angle（格林威治时角）转换为小时。

5.The calculation of the position of a star relies heavily on the Greenwich hour angle (格林威治时角) to determine its angular distance from the Greenwich meridian.

星体位置的计算在很大程度上依赖于Greenwich hour angle（格林威治时角），以确定其与格林威治子午线的角距离。

作文

The concept of the Greenwich hour angle is essential in the field of astronomy and navigation. It refers to the angular measurement of time, expressed in degrees, that represents the angle between the Greenwich meridian and the meridian of a celestial body. This angle helps astronomers and navigators determine the position of objects in the sky relative to the Earth, enabling accurate positioning and timekeeping. Understanding the Greenwich hour angle is crucial for anyone involved in celestial navigation, as it provides a framework for calculating the local time based on the position of celestial bodies.To grasp the significance of the Greenwich hour angle, one must first understand the concept of the Greenwich meridian, which is the prime meridian at zero degrees longitude. This line runs from the North Pole to the South Pole and serves as the reference point for time zones around the world. The Earth rotates 360 degrees in approximately 24 hours, meaning it rotates about 15 degrees every hour. Therefore, the Greenwich hour angle can be calculated by determining how far a celestial object is from the Greenwich meridian in terms of degrees.For example, if a star is located directly above the Greenwich meridian, its Greenwich hour angle is 0 degrees. If the star is positioned 30 degrees west of the meridian, its Greenwich hour angle would be 30 degrees. Conversely, if it is 60 degrees east of the meridian, the Greenwich hour angle would be 300 degrees (360 - 60). This system allows navigators to pinpoint their location and the time at sea accurately.The Greenwich hour angle is also instrumental in the calculation of Universal Time (UT), which is based on the mean solar time at the Greenwich meridian. By knowing the Greenwich hour angle of a celestial body, one can convert local solar time to UT, facilitating communication and coordination across different time zones.In practical applications, sailors and aviators utilize the Greenwich hour angle when plotting courses or determining their position on a chart. They often use sextants to measure the altitude of celestial bodies, which, combined with the Greenwich hour angle, allows them to calculate their latitude and longitude accurately. This method of navigation has been used for centuries and remains relevant today, despite advancements in technology.In conclusion, the Greenwich hour angle is a fundamental concept in astronomy and navigation that aids in determining the position of celestial bodies relative to the Earth. Its significance extends beyond theoretical knowledge, as it plays a vital role in practical navigation and timekeeping. By understanding the Greenwich hour angle, individuals can enhance their skills in celestial navigation and contribute to the accuracy of global positioning systems. Overall, this concept exemplifies the intersection of science and practical application, highlighting the importance of precise measurements in our understanding of the universe.

“格林威治时角”这一概念在天文学和导航领域中至关重要。它指的是时间的角度测量，以度数表示，代表格林威治子午线与天体子午线之间的角度。这个角度帮助天文学家和导航员确定天空中物体相对于地球的位置，从而实现准确的定位和计时。理解“格林威治时角”对任何参与天体导航的人来说都是至关重要的，因为它提供了一个基于天体位置计算当地时间的框架。要理解“格林威治时角”的重要性，首先必须了解格林威治子午线的概念，它是零度经线的主子午线。这条线从北极延伸到南极，并作为世界各地时区的参考点。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，可以通过确定天体距离格林威治子午线的度数来计算“格林威治时角”。例如，如果一颗星星正好位于格林威治子午线正上方，则其“格林威治时角”为0度。如果这颗星星位于子午线以西30度，则其“格林威治时角”为30度。相反，如果它位于子午线以东60度，则“格林威治时角”为300度（360 - 60）。这个系统使导航员能够准确地确定他们的位置和海上的时间。“格林威治时角”在计算世界协调时间（UT）时也非常重要，UT基于格林威治子午线的平均太阳时间。通过知道天体的“格林威治时角”，人们可以将当地太阳时间转换为UT，从而促进不同时间区之间的沟通和协调。在实际应用中，水手和飞行员在绘制航线或确定他们在图表上的位置时会利用“格林威治时角”。他们通常使用六分仪测量天体的高度，这结合“格林威治时角”使他们能够准确计算自己的纬度和经度。这种导航方法已经使用了几个世纪，并且尽管技术有所进步，但今天仍然相关。总之，“格林威治时角”是天文学和导航中的基本概念，有助于确定天体相对于地球的位置。它的重要性超越了理论知识，因为它在实际导航和计时中发挥着重要作用。通过理解“格林威治时角”，个人可以提高他们在天体导航方面的技能，并为全球定位系统的准确性做出贡献。总体而言，这个概念体现了科学与实际应用的交汇，突显了精确测量在我们理解宇宙中的重要性。