Never heard of this before...
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Never heard of this before...
Hi Guys, I'm looking at the CASA Part 61 Syllabus both PPL/CPL and on the Navigation section in point (F) there is a mention of 'RELATIVE HEADING'. What is that? I have searched and searched on line and there is NOTHING about it.
"2.1 Form of the earth
2.1.1 Describe:
(a) the shape and rotation of the earth;
(b) latitude, longitude;
(c) the difference between true and magnetic north;
(d) how distance and direction are measured and applied to navigation;
(e) magnetic variation and compass deviation;
(f) the relationship between magnetic heading, relative heading and magnetic bearing."
Any help is appreciated in explaining this mystery term.
"2.1 Form of the earth
2.1.1 Describe:
(a) the shape and rotation of the earth;
(b) latitude, longitude;
(c) the difference between true and magnetic north;
(d) how distance and direction are measured and applied to navigation;
(e) magnetic variation and compass deviation;
(f) the relationship between magnetic heading, relative heading and magnetic bearing."
Any help is appreciated in explaining this mystery term.
Two seconds on Google
https://en.wikipedia.org/wiki/Bearing_(angle)
"In nautical navigation the relative bearing of an object is the clockwise angle from the heading of the vessel to a straight line drawn from the observation station on the vessel to the object.
The relative bearing is measured with a pelorus or other optical and electronic aids to navigation such as a periscope, sonar system, and radar systems. Since World War II, relative bearings of such diverse point sources have been and are calibrated carefully to one another. The United States Navy operates a special range off Puerto Rico and another on the west coast to perform such systems integration. Relative bearings then serve as the baseline data for converting relative directional data into true bearings (N-S-E-W, relative to the Earth's true geography). By contrast, Compass bearings have a varying error factor at differing locations about the globe, and are less reliable than the compensated or true bearings.
The measurement of relative bearings of fixed landmarks and other navigational aids is useful for the navigator because this information can be used on the nautical chart together with simple geometrical techniques to aid in determining the position of the vessel and/or its speed, course, etc.
The measurement of relative bearings of other vessels and objects in movement is useful to the navigator in avoiding the danger of collision.
https://en.wikipedia.org/wiki/Bearing_(angle)
"In nautical navigation the relative bearing of an object is the clockwise angle from the heading of the vessel to a straight line drawn from the observation station on the vessel to the object.
The relative bearing is measured with a pelorus or other optical and electronic aids to navigation such as a periscope, sonar system, and radar systems. Since World War II, relative bearings of such diverse point sources have been and are calibrated carefully to one another. The United States Navy operates a special range off Puerto Rico and another on the west coast to perform such systems integration. Relative bearings then serve as the baseline data for converting relative directional data into true bearings (N-S-E-W, relative to the Earth's true geography). By contrast, Compass bearings have a varying error factor at differing locations about the globe, and are less reliable than the compensated or true bearings.
The measurement of relative bearings of fixed landmarks and other navigational aids is useful for the navigator because this information can be used on the nautical chart together with simple geometrical techniques to aid in determining the position of the vessel and/or its speed, course, etc.
The measurement of relative bearings of other vessels and objects in movement is useful to the navigator in avoiding the danger of collision.
- Example: The navigator on a ship observes a lighthouse when its relative bearing is 45° and again when it is 90°. He now knows that the distance from the ship to the lighthouse is equal to the distance travelled by the vessel between both observations."
It seems like a mistaken term that should be True/Absolute Heading or Relative Bearing. A relative bearing from the aircraft could be considered a relative heading to an object I suppose when overlaid on a DG or such. It's just not a term used.
