Azimuth

Measure the distance between stars

So much for the observation of constellations such as the night sky in general and the generation of high-quality photographs, it is important to know the concepts of azimut and elevation. That is the topic of the post. You have to know what the azimuth is and what it is for in order to get the most out of the photos in which you can see the Sun and the moon at the same time or to find certain constellations in the sky.

In this post we teach you everything about azimuth and how to use it.

What is azimuth?

Azimuth

Both azimuth and elevation are two coordinates that are centered on define the position of a celestial body in the sky when we observe it from a specific position and in a certain time. That is, it is used to be able to know the position that the Sun, the moon or another star will have at any time, depending on the position in which we find ourselves. If we want, for example, to visualize some constellation in the sky such as the Great Bear we can look for certain stars that allow us to detect them. To do this, we use elevation and azimuth.

Many photographers use these coordinates to find the position of the moon in broad daylight and to take incredible photos of both celestial bodies in the sky at the same time. The position of the Sun and the Moon in the sky is defined by the azimuth and elevation.

Azimuth is nothing more than the angle that any celestial body makes with North. This angle is measured from a clockwise direction and around the observer's horizon. Therefore, the situation in which we find ourselves is important in order to determine the position of the celestial body. These coordinates do not determine the direction of the celestial body. If we have measured a celestial body that is North, we will see that it has an azimuth of 0 °, one to the East 90 °, one to the South 180 ° and to the West 270 °.

There are mobile applications that save information about the elevation and azimuth of the sun and moon for different dates and times that we want to see. It is usually represented by a map of azimuth and elevation lines in time.

What is elevation?

Elevation

When we talk about elevation, we are referring to the vertical angular distance between the celestial body in question and the horizon seen by the observer. TO this is called the local plane of the observer. For the observer who is at ground level, the elevation of the Sun generates an angle that forms the direction of its geometric center with the horizon that we observe in that position.

For example, the elevation of the Sun or the Moon can be 12 ° when its geometric center is located at 12 ° above the horizon that we see from the point where we are. If you want to photograph this, you have to take into account the position of the Sun or the moon and you have to calculate the elevation. For these types of photos, this is the most difficult step. To learn to handle the concepts of azimuth and elevation it is better to see studies of real examples.

Azimuth and heading in topography

Quadrant

Another of the uses that these concepts have are applied in the world of topography and geodesy. The course is the one measures from north or south and clockwise or counterclockwise. However, it can only be measured up to 90 °.

Both bearing and azimuth are closely related to each other in this field of study. The difference between these concepts can be seen in that the azimuth of a line can be calculated only knowing the heading, but not vice versa.

We can try to determine the value of the line that joins any two points, as long as we can know the coordinates of north and east. There is a formula as long as the azimuth is in the first quadrant:

Azimuth Formula

In this formula, Delta is the difference between the Easting coordinates of the arrival point and the Easting coordinates of the starting point. It is always necessary to take into account the position of the dial in which the azimuth is located.

Measuring instruments

Crossbow

The quadrant and the crossbow are two instruments that are used to observe the stars in the sky. The quadrant is used to calculate the height of the stars on the horizon. If we want to know how high the Sun is, we must be careful not to look at it directly or we will damage our eyes.

When the dial is focused on the Sun, it can be seen how the rays of light will penetrate through it and will be projected. That's when you know you're perfectly aligned with it. Once it is aligned, we take the reading on the dial and that is the height of the Sun above the horizon.

And what if there is no sunlight to penetrate the quadrant? Nothing happens. At night it can be used to locate a star and know its height. The same procedure is followed, but in this case you will be able to look directly at the star, focus it and look at the quadrant to know its height.

On the other hand, To know the angular distance between two stars, the crossbow is used. You have to place the crossbow above your head, placing the stick next to the nose. We put the origin of the ruler on the star that we want to visualize and we will count the number of divisions until we reach the other star that we want to measure. This number that we have achieved will be the degrees of separation between the two.

As you can see, concepts like azimuth, elevation, and heading are quite important for measuring things that are out of our reach. They are estimates with a high degree of precision and with many useful fields in different sciences, from topography to stargazing.


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