Line of sight: Difference between revisions
Content deleted Content added
m antenna is mis-written as "antennae" |
m v2.05b - Bot T20 CW#61 - Fix errors for CW project (Reference before punctuation) |
||
| (41 intermediate revisions by 28 users not shown) | |||
| Line 1: | Line 1: | ||
{{short description|Unobstructed line between an observer and a subject of interest}} |
|||
:''See also: [[line of sight (gaming)|line of sight]] in [[gaming]], referring to visibility of units.'' |
|||
{{other uses}} |
|||
The '''line of sight''', also known as '''visual axis''' or '''sightline''' (also '''sight line'''), is an [[imaginary line]] between a viewer/[[observation|observer]]/[[wikt:spectator|spectator]]'s [[eye]](s) and a subject of interest, or their [[relative direction (geometry)|relative direction]].<ref>{{Cite web |title=What is line of sight (LOS) and why is it important? |url=https://www.techtarget.com/whatis/definition/line-of-sight-LOS |access-date=2024-02-08 |website=WhatIs |language=en}}</ref> The subject may be any definable object taken note of or to be taken note of by the observer, at any distance more than least distance of distinct vision. In [[optics]], refraction of a ray due to use of [[lenses]] can cause distortion.<ref>{{Cite web |title=What is Lens Distortion Correction {{!}} How Does LDC Work? |url=https://info.verkada.com/lens-distortion-correction/ |access-date=2024-02-08 |website=info.verkada.com |language=en-us}}</ref> Shadows, patterns and movement can also influence line of sight interpretation<ref>{{Cite web |title=What does line of sight mean? |url=https://www.definitions.net/definition/line+of+sight |access-date=2024-02-08 |website=www.definitions.net}}</ref><ref>{{Cite journal |last=Mamassian |first=Pascal |last2=Knill |first2=David C. |last3=Kersten |first3=Daniel |date=1998-08-01 |title=The perception of cast shadows |url=https://www.sciencedirect.com/science/article/pii/S1364661398012042 |journal=Trends in Cognitive Sciences |volume=2 |issue=8 |pages=288–295 |doi=10.1016/S1364-6613(98)01204-2 |issn=1364-6613|doi-access=free }}</ref> (as in [[optical illusions]]). |
|||
The term "line" typically presumes that the [[light]] by which the observed object is seen travels as a straight [[ray (optics)|ray]], which is sometimes not the case as light can take a curved/angulated path when [[reflection (physics)|reflect]]ed from a [[mirror]],<ref>{{Cite web |title=Physics Tutorial: Reflection of Light and Image Formation |url=https://www.physicsclassroom.com/class/refln/Lesson-3/Reflection-of-Light-and-Image-Formation |access-date=2024-02-08 |website=www.physicsclassroom.com}}</ref> [[refract]]ed by a [[lens]] or [[density]] changes in the [[optical medium|traversed media]], or [[gravitational lens|deflected by a gravitational field]]. Fields of study feature specific targets, such as vessels in navigation, marker flags or natural features in surveying, celestial objects in astronomy, and so on. To have optimal observational outcome, it is preferable to have a completely unobstructed sightline. |
|||
When viewing a [[scene]], as in [[optics]], [[photography]], or even [[hunting]], the '''line of sight''' is the straight line between the [[observer]] and the [[target]]. In [[astronomy]], when the distance between the observer and the distant objects is large, the light of sight can often be taken as the [[straight line]] between the [[earth]] and the [[target]]. |
|||
---- |
|||
==Applications== |
|||
'''Line of sight''' is commonly used to refer to [[telecommunication]] links that rely on a line of sight between the transmitting antenna and the receiving antenna. Such capability is necessary for high frequency [[microwave]] links that offer relatively high [[bandwidth]] communication circuits. Typical operating frequencies are in the gigahertz frequency range where the radio path is not reflected or refracted to any great extent. Occasionally this term is mis-written as "line of site". |
|||
* [[Sightline (architecture)]] |
|||
* [[Line-of-sight range]] |
|||
* [[Line-of-sight (missile)]], the straight line between the missile and the target |
|||
* [[Radar horizon]] |
|||
* [[Line-of-sight propagation]], electro-magnetic waves travelling in a straight line |
|||
** [[Non-line-of-sight propagation]] |
|||
* [[Line-of-sight fire]], shooting directly at a visible target on a relatively flat trajectory |
|||
* [[Line-of-sight velocity]], an object's speed straight towards or away from an observer |
|||
* Line-of-sight [[double star]], one in which two stars are only coincidentally close together as seen from Earth |
|||
* [[Beyond visual line of sight]] |
|||
==References== |
|||
Typical transmission path lengths are of the order of forty miles (60 km) but the height of the antenna and intervening terrain have significant influence. Many links are now being upgraded to [[fibre optic cable]]. |
|||
{{reflist}} |
|||
{{wikt}} |
|||
Line of sight is also be necessary for optical transmission systems which can be used for short distances, between two high buildings, where a cable link might be very long. |
|||
[[ |
[[Category:Geometry]] |
||
[[category:radio frequency propagation]] |
|||
Latest revision as of 08:01, 19 February 2024
The line of sight, also known as visual axis or sightline (also sight line), is an imaginary line between a viewer/observer/spectator's eye(s) and a subject of interest, or their relative direction.[1] The subject may be any definable object taken note of or to be taken note of by the observer, at any distance more than least distance of distinct vision. In optics, refraction of a ray due to use of lenses can cause distortion.[2] Shadows, patterns and movement can also influence line of sight interpretation[3][4] (as in optical illusions).
The term "line" typically presumes that the light by which the observed object is seen travels as a straight ray, which is sometimes not the case as light can take a curved/angulated path when reflected from a mirror,[5] refracted by a lens or density changes in the traversed media, or deflected by a gravitational field. Fields of study feature specific targets, such as vessels in navigation, marker flags or natural features in surveying, celestial objects in astronomy, and so on. To have optimal observational outcome, it is preferable to have a completely unobstructed sightline.
Applications[edit]
- Sightline (architecture)
- Line-of-sight range
- Line-of-sight (missile), the straight line between the missile and the target
- Radar horizon
- Line-of-sight propagation, electro-magnetic waves travelling in a straight line
- Line-of-sight fire, shooting directly at a visible target on a relatively flat trajectory
- Line-of-sight velocity, an object's speed straight towards or away from an observer
- Line-of-sight double star, one in which two stars are only coincidentally close together as seen from Earth
- Beyond visual line of sight
References[edit]
- ^ "What is line of sight (LOS) and why is it important?". WhatIs. Retrieved 2024-02-08.
- ^ "What is Lens Distortion Correction | How Does LDC Work?". info.verkada.com. Retrieved 2024-02-08.
- ^ "What does line of sight mean?". www.definitions.net. Retrieved 2024-02-08.
- ^ Mamassian, Pascal; Knill, David C.; Kersten, Daniel (1998-08-01). "The perception of cast shadows". Trends in Cognitive Sciences. 2 (8): 288–295. doi:10.1016/S1364-6613(98)01204-2. ISSN 1364-6613.
- ^ "Physics Tutorial: Reflection of Light and Image Formation". www.physicsclassroom.com. Retrieved 2024-02-08.
Look up line of sight in Wiktionary, the free dictionary.