Great Circle ( GC) Track. Calculation of GC dist, initial and final course Part 1
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- Опубликовано: 26 авг 2024
- Explains why GC dist is shortest possible distance on the surface of earth. Example to calculate GC dist, initial course and final course.
Looking forward to more, Captain.
+justacondom
Thanks for your concern. Presently I am sailing on board a ship and you can expect some videos next week onward or so.
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So awesomely simplified. Thanks!
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So to clarify 36DEG at first is initial GCT from A to B at A. 133DEG is GCT from B to A. And 46DEG is GCT at B from A to B?
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Quite finely understood
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At 6:23 Is the green circle a great circle? If it is then you are drawing the distance through the center of the earth. The only way it makes sense is if the green circle isn't a circle but two longitude lines. What makes it confusing is that the green lines are an ellipse which is what a circle appears to be when it's seen at an angle. The longitude lines should not form an ellipse if they are that close together. The ambiguity makes your explanation difficult to follow. Maybe I'll attempt to continue watching and then go back to the ambiguous point later.
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Thank you, very helpful.
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excuse me sir the first angle you measured clockwise but the second one you did counterclockwise, why ? , I am trying to do a navegation system for an aircraft, does the cosine law work for the heading angle ? or should i use other method. !!!! thank you for your time
There is difference between course angle that is angles A or B obtained in triangle PAB and the course. The course in marine navigation is always measured anticlockwise from meridian ( curved lines on the globe joining poles ) i.e N- S line ( straight line on the chart ). Here course angle A gives the course equal to angle A itself in anticlockwise direction. Course angle B is opposite to angle A and in different quadrant but ships heading is from A to B. Hence we need to find angle of ships head from N-S line ( 14:18). Also pls watch ruclips.net/video/5ufMFHazUFw/видео.html
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Hi. I need a globe 3D great circle thru New York City (40.7128° N, 74.0060° W)
with a heading of 90 or 270 degrees. Can you create a Geogebra app like that for me?
kind regards,
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U have minus the B angle with 180 deg than how it could be NE bcz NE is an angle less than 90 itself therefore no need to subtract and read it same way .. The angle B is a South east course therefore u subtracted it with 180 deg ..
Do reply
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I love that calculator
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how would I know if to take it away from 180
In solving triangle PAB, you are finding angle A and B. You need to convert angles into course which is measured from N-S meridian ( line joining pole, which looks straight on chart). Initial course you can keep the angle A like this. For final course subtract B from 180 because angle B is at the stern of ship where as course is measured to the ship head from N-S line. Hope thi answer the question . Pls watch to know more about course.
ruclips.net/video/5ufMFHazUFw/видео.html
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thank you sir .. can you please make video on chartwork problems and cargo work problems! plz help us sir
Sure... Cargo Work.. On the way. Chart work within a month...
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What method used sir
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nice work .
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Could pls tell if limiting lat and final lat same.. How to solve Gc.. Question
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Hi sir excellent work, i checked with google maps and the distance is about 2.932km what am i doing wrong?
Pls convert to nautical mile. Since nautical miles vary with lat, average mean value is 1.8523.
So this 2932 km will equal to 1582.896 nautical mile. The GC dist obtained in question is 1579.6 nautical mile which conisders earth as true sphere. Hope this clarifes.
thank you so much for your quick answer, now i see the relation, just one last dumb question why did you multiply ab result by 60 ? im so sorry for this questions
One degree of arc = 60 minute of arc. Hence the degree is converted into minutes. One minute of arc corresponds to one nautical mile by definition.
thank you so much for your time, you are a lifesaver
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sir can you please explain in detail about final course B how i have to name it?
very convenient
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I cannot get the 26.32660753
My calculator is always giving me the answer of 0.8962805764
press 'shift cos' after you get 0.8962805764 and then '=' then you will get 26.32660753
He's confused...
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