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A position line or line of position (LOP) is a line (or, more generally, a curve curve) that can be both identified on a chart (nautical chart or aeronautical chart) and observed on the surface of the earth. Compass bearing – the angle between north and the line passing through the compass and the point of interset.
What is the use of position line?
The position line is a line on the surface on the earth which you can use to determine the location of a vessel. On a position line the ranges, bearings and distance can be found. Range is when two landmarks form a line, for example when a lighthouse is aligned with a mountaintop or a hill.
Can a distance or range be used instead of danger bearing?
Danger Bearing Hatching is included on the side that is hazardous, along with its compass bearing. When a distance instead of a direction is used a danger range is plotted much the same way as the danger bearing.
How do you find line of position?
How to do a Line of Position
- Correct the sextant reading to get HO (height of object)
- Convert the time of the sight to LHA (local hour angle of the body)
- Using the LHA and Declination from the time of your sight, look up the HC (predicted height of object) in the tables of a whole line of latitude near you.
What is a bearing in navigational terms?
In navigation, bearing is the horizontal angle between the direction of an object and another object, or between it and that of true north. For example, an object relative bearing of 0 degrees would be dead ahead; an object relative bearing 180 degrees would be behind. Bearings can be measured in mils or degrees.
How do you find the position line?
Fixes are a necessary aspect of navigation by dead reckoning, which relies on estimates of speed and course. The fix confirms the actual position during a journey. A fix can introduce inaccuracies if the reference point is not correctly identified or is inaccurately measured.
Why a vessels position should be plotted by bearing?
Moreover, bearings on distant objects bring about more uncertainty in our position fix as the error sector widens. The position fix is plotted by taking bearings at two light-vessels as their lights appear over the horizon . The variation is −1° and the ship’s compass heading is 190°.
What is electronic navigational aid?
Electronic navigation are forms of navigation that ships, land vehicles, and people can use, which rely on technology powered by electricity. Methods of electronic navigation include: Satellite navigation, satellite navigation systems. Radio navigation, the application of radio frequencies to determining a position.
Main navigation gives shape to a site. In many ways, the main navigation defines the boundaries of the site itself. The main navigation is often presented in a global navigation area, which generally includes the site logo and utility navigation. (See the following section for more on utility navigation).
How are position lines used in celestial navigation?
Single position lines can still be useful though as you can use them as advanced lines of position. Particularly when doing celestial navigation. Dead Reckoning – DR means determining your current position by projecting your course over the ground and speed from a known previous position.
How is local navigation different from global navigation?
Local navigation often works in conjunction with a global navigation system and is really an extension of the main navigation. Because local navigation varies more often than main navigation, it is often treated differently.
Structural navigation can be further subdivided into two types: main navigation and local navigation. Also called: global navigation, primary navigation, main nav. The main navigation generally represents the top-level pages of a site’s structure—or the pages just below the home page.