A person's ability assess by eye, without the aid of instruments, the distance to surrounding objects and the size of objects is called the eye.
The accuracy of the distance eye varies. At a distance of 1 km or more errors as high as 50% or more, at short distances are much smaller, and people experienced no more than 10%. In this case, the relative distances (near, on, above, below) eye estimates are much more accurate than the absolute.
Everyone there is inherent only distinguishing features of his subjects. They need to find out through personal observations. Ability by eye assess distance in terms of visibility of individual items acquired through the use of individual characteristics of visibility, which are set as follows.
Magnitude of errors in the determination of the distances to the naked eye is characterized by the following table:
Observer determines to eye different distances, using for this purpose the following table, it provides a degree of reduction of the height of objects, depending on the distance.
This takes into account the effect of the above factors on the visibility of objects. Then, set the visual way distances are checked on the map or directly measured steps and determined the value of error. Such determination of the distances and the test repeated in different visibility conditions as long as the observer does not gain the necessary skills for which bug will not exceed 10%.
Installed in this way is especially likely observer puts in notes the distance from which it begins to distinguish surrounding objects.
Memo must constantly check, correct and supplement the new data that will help determine the most accurate distance.
It is useful to note in the "other factors" atmospheric phenomena, with the watch, using the following symbols adopted in meteorology (see signs on page 57).
Accurate eye – Individual human ability that can be developed through constant and patient exercises.
Plainsman good estimates distance out of the blue, but the blunder in the mountains and the sea. Urbanite is often lost when it needs to determine the distance to the wild. Necessary for the development of eye estimation in different terrain conditions, in different weather exercise our eyes in a certain distance, comparing the results with distances measured by a precise technique. In the development of eye estimation huge role played by tourism, mountaineering, hunting and sports games: football, hockey, tennis, skittles, basketball, volleyball and other sports.
To be able to find their way, you need to master the skills of the most rapid and accurate determination of the simplest ways of distances and sizes of the observed objects – a necessary element of orienteering. Consider some of these methods.