How to estimate distance by a telescope

In summary, telescopes for estimating distance to a target object must be calibrated in order to accurately determine the distance. This can be achieved through stadiametric rangefinding or using dedicated instruments such as tacheometers. Some rifle scopes and golf scopes also have calibrated reticles to aid with aiming and distance estimation.
  • #1
zli034
107
0
Guys

I don't know if people could estimate distance to a target object by looking through a telescope. I believe telescopes for this kind use must be calibrated some how. When the time people sailed in the ocean and when they spotted another boat by the telescope, how did they tell the distance?

thanks
 
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  • #2
Well, if you know how big a boat is, and you know how big it looks in a telescope... combining that with the magnification of the telescope tells you how far away it is.

Maybe I'm unclear on what you're asking.
 
  • #3
Many instruments, such as the telescopes in surveyors' theodolites possesses calibrated marks which give a distance factor of 100 when a staff or ruler is viewed. These are called stadia marks.

http://en.wikipedia.org/wiki/Stadiametric_rangefinding

Surveyors also use dedicated instruments which can provide both horizontal and vertical measurement by this means. these are special theodolites, called tacheometers.

http://en.wikipedia.org/wiki/Tacheometry

go well
 
  • #5
Some rifle scopes have calibrated reticles (typically with spacing conforming to the body size of a deer or similar) to help with aiming (elevation). Golfers have scopes calibrated to standard flag-pin heights so that golfers can estimate the distance to the hole and make their club selections. These are forbidden in pro golf so golfers have to rely on their caddies' notes and experience instead.
 
1)

What is the formula for estimating distance by a telescope?

The formula for estimating distance by a telescope is known as the angular size-distance formula, which states that the distance of an object can be determined by dividing its actual size by its angular size (measured in degrees) as seen through the telescope. This formula is: Distance = Actual size / Angular size.

2)

What factors can affect the accuracy of distance estimation through a telescope?

There are several factors that can affect the accuracy of distance estimation through a telescope, including atmospheric conditions, the quality and magnification of the telescope, and the observer's skill and experience in using the telescope. Light pollution and the object's location in the sky can also play a role in the accuracy of distance estimation.

3)

Can a telescope be used to accurately estimate the distance of objects in space?

Yes, a telescope can be used to accurately estimate the distance of objects in space. In fact, telescopes are one of the main tools used by astronomers to measure the distance of objects in the universe. However, the accuracy of the estimation may vary depending on the factors mentioned above and the type of telescope being used.

4)

How can parallax be used to estimate distance with a telescope?

Parallax is the apparent shift in the position of an object when viewed from different angles. This phenomenon can be used to estimate distance with a telescope by measuring the parallax angle of an object and using the parallax formula, which states that distance = 1/parallax angle. This method is often used for estimating the distance of nearby objects in our solar system.

5)

Are there any alternative methods for estimating distance with a telescope?

Yes, there are alternative methods for estimating distance with a telescope, such as using the redshift of an object to determine its distance. This method is based on the principle that the further an object is from us, the more its light will appear "shifted" towards the red end of the light spectrum. This method is commonly used for estimating the distance of objects in the far reaches of the universe.

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