What is the angular distance?

The angle distance is the measure of the apparent department between two points from the perspective of the observer. The direct lines spread from each point to the intersecting observer. The angle of the intersection of these two lines is an angular distance and is usually expressed in degrees or radians. In trigonometry, this angle can be used to calculate height and distance. Astronomers often use an angle to describe an apparent separation between heavenly bodies without reference to their actual distance.

The common problem with trigonometry involves calculating the height of the building. The line of the angular department of the vision between the upper and lower part of the building at a known distance is sufficient information for determining its height. Calculations involving angular distance are common in exploration and targeting. Instead of degrees or radios, the army is often considered to be useful to express the calculations of targeting in terms of Angular Mil. This is 1/6400 perimeter of the circuit, or more comfortably, the angle distance between two points separated by one meter in the range of 1000 meters.

There are two basic ways to describe the position of the object in the sky in astronomy. One is a reference to the coordinate system, the other is according to the position of the object due to the other body. In the equatorial coordinate system, the earthly poles and equals are projected into space like heavenly poles and heavenly equator. The position of the body is described by its declination, degrees north or south of the heavenly equator and its hourly angle. This is an angular distance along the heavenly equator between the position of the observer and the heavenly meridian, a circle passing directly above the observer and through the heavenly poles.

For amateur, the angular distance could be used to find an astronomical object in relation to a well -known body or just in recording an interesting function. Everything that is necessary is often stretched hand. On the length of the arm, the tip of the small finger is about one degree of arch. Three middle fingers are about four degrees and a closed fist of about ten. VzIt covers about 18 degrees from the small finger to the thumb of the open hand.

Professional and more serious observer often uses measurement of similar angular distances called angular diameter. This is the obvious size of an astronomical object, as can be seen from the ground. These diameters are relatively small and are usually measured in arches or 1/600. degrees. As with terrestrial measurements, as far as the distance to the object is known, its angular diameter can be used to calculate its actual size.