I'm a veteran of the British Army (royal tank regiment), and keen hill walker. The use of an azimuth is when you know where you have travelled and recorded your bearing and/or azimuth changes. I often go for walks with no destination set at the outset. The point is to walk and pick a direction and head in that direction until it intersects with something (my new meridian). So, if we were using your wall (meridian) yes we could pick any point for us to make up an azimuth to head along, and we could end up in any place parallel to each other uf the wall was straight like diagonal chevrons painted on the back of a highways vehicle. However if you use a distinguishable point along the wall ie a stile, a gate, a sign or even a broken part if the wall or tree something describable and identifiable you can record that as I do and look about find a direction and take an azimuth reading from my (locator along my meridian). If anyone was needing to come to my location say I'm injured and called for mountain rescue, I can lead them along my azimuth to key meridian landmarks ie stile, gate sign tree broken wall etc and the azimuth from that locator. So azimuth does work provided the locator along the meridian is distinguishable to make the azimuth accurate to lead in the correct direction but azimuth only work if you are following directions and not just wandering aimlessly and then the search team are using an azimuth to find uou, they only work if you first record your azimuth from the first key locator (your car hotel bus/train stop cafe etc). Then every direction change is recorded so I take an azimuth of 143 and meet your wall, I record the 143 azimuth from my cars rear bumper facing across the road out of the carpark. When I meet your wall I turn east along the south side of the wall and walk 300m until I meet the stone stile, I then take an azimuth of 40 and follow to my accident in a field 240m from the wall in a depression. So azimuth can and are used effectively and provided they are recorded accurately as you go, they can save your life if rescue is needed. Even if I'm not on an azimuth trail (wandering about lol) I still record my headings and distances and landmarks from departure to my current location, just incase I'm injured and need to get rescue to me. They ain't spending two days searching they know exactly where to find me before they even leave the offices. If I could advise anyone if anything that would be my advice. Record every direction turn landmarks and distance /timing you can in as much detail as you can, the more accurate, the faster help gets to you. Happy walking
For added confusion, you could address 'yaw'; the difference between the direction you're pointing and the actual direction of travel. For maritime purposes, azimuth is relative to the ships centreline running through the bow.
Superb. Just a tiny correction about military navigation, we used mils in my day both on our prismatic (lensatic?) compass and for eg. mortar plotting. 6400 miles to a circle. Brilliant video btw. I can’t recall using a baseplate compass. Ironic term since the mortar has a baseplate. But I can’t imagine a baseplate compass, which is all most people ever need, in mils.
Well, we can blame ship navigators for this (I think) because that's where the difference between the two terms is most important. Azimuth is just an angle relative to the ship, with 0 being straight ahead. And this leads to the best description I know: bearings are measured relative to North, azimuths are measured relative to any other direction.
Many thanks. I’ve taught civilian navigation for years and always wondered what ex military folks were talking about. Now I know! (I’ll still only use bearings from the north though 😂)
This is something completely new to me. Never heard of it, seen it or used it before. It is interesting to know, but I will probably never use it. It could be too confusing for the local scout group to whom I occasionally teach some map and compass techniques. The military system N46°E mentioned here is well known to me, but is also never used. I limit myself to the 360° right-turning system. Of course, I will try to remember this in case I ever have to deal with it. Thank you for explaining this to us. A valuable contribution.
Very interesting lecture for the first time I hear azimuth and versus Bearing. I have always used azimuth as going in a given direction without a compass just in the direction to go in the same direction using the nature of the sun or other signs. It is close to your explanation.
Hmmmm . . . I learned navigation in the US Navy. What you are calling "bearing", I'd call "heading." Heading is an angle relative to North, usually true North. So when the captain wants to know what direction the ship is going, he asks for the heading. Bearing is relative to an arbitrary datum line, usually the centerline of the ship. So the direction to a lighthouse would be given relative to the ship. "What's the bearing of the lightshoue?" 90 degrees! Which would put it off the starboard side. These terms were also in use in civil aviation when I learned to fly.
Thanks. :) I feel a sense of dread when things like this happen... It seems there's no good way to handle mass misconceptions. I appreciate that you've provided a way to know the truth in creating this video.
Thank you for the video, not to forget, that an azimuth take from a Grid North, on a map and a Bearing measured from Magnetic North, with a sighting compass, may have a declination error between them..
In engineering field, azimuth is just one of the angles that define a spherical coordinate system. The meridian can be thought as one of the coordinate axes and the azimuth is just one of the two angles that define a space direction (azimuth and elevation). I guess that the problem is that someone gave to azimuth a "magnetic property" while it is instead just an angle with respect to a specific frame of reference (the meridian in your example). On the other hand, bearing lives in the navigation field and its an angle that is related to the magnetic north.
I once had a person reading a legal description of land. Each leg of the description started with the direction “thence run..followed by the bearing of degrees, minutes and seconds. This person asked me how fast they should run.
I am not so dumb as people think, 😇 I had a good idea what an azimuth was; We use to use it in the repair and alignment of old tube radios and new it was to do with angles and can be checked with a protractor. 😋. thank you Mr Map Man
That distinction might be handy close to the poles. If you are at a base located at the south pole all bearings and meridians on the globe converge under your feet. Using a local meridian that is identifiable might work better at local navigation around the environs of your base. Perhaps a fence line around the perimeter of the installation.
I thought that I was differentiating bearings vs azimuths, but really the explanation below only differentiates grid bearings/azimuths (on a mapping plane) from true bearings/azimuths. From a background in surveying, these are two characteristics that differentiate my understanding of bearings vs azimuths: The first characteristic of an azimuth is that an azimuth changes as you move along the line whereas a bearing will remain constant from beginning to end. The line shown at 5:15 is referenced in my explanation. Whether it is an astronomic, magnetic, or geodetic azimuth they all reference a northernly point from which a local meridian is created (from the observer to the magnetic north pole in this example); however, as you move along the line (in red) and take another observation a new local meridian will be created that is not parallel with the previous local meridian but still considered to be 0° along this new meridian. The result is that the exact same line (in red) now will be a different azimuth than what was observed at the previous starting location (somewhere). The difference will be negligible for walking distances but if we are travelling a long distance then the magnetic azimuth will noticeably change (and this change is not to be confused with greater circles and rhumb lines/loxodromes in mapping projections. The second characteristic is that back-bearings (reverse bearings) of a bearing are a simple calculation: for example, 45° forward from somewhere will be (45° + 180°) 225° backwards from somewhere else. Direct and inverse azimuths are not computed as easily. Because azimuths are all converging to a central point (in this case the Magnetic North Pole), spherical trigonometry is used to calculate the direct and inverse azimuth. I think the video explains azimuths well from a navigational standpoint they are referencing a meridian and turn in a clockwise rotation. By the way, in surveying we call your military bearings 'quadrant bearings' (S60E), and confusingly your civilian bearings 'azimuths' haha, which is why I like to call them 'full-circle bearings' (240°). note: 'grid bearings' are also a good term for your civilian bearings.
I love you channel. I just say RUclips turned off comments for your trig point video. I have no idea why. I commented on it a while ago - it was brilliant.
Greetings from Brazil. As a radio amateur (PU5YUR), ex boyscout and ex army corporal I have recently regained interest in analog navigation and have to say yours are the best videos available on the subject. I have two unrelated questions though. From your videos and from a recent trip to London, I noticed that your landscape always seems to have been recently mowed 😊. I can't imagine traveling to the countryside in my country without being instantly surrounded by thick vegetation so I have the false feeling that it would be almost impossible to get lost in the UK. How can there be so few trees around there? The other question is: what's that dark animal chasing the sheep in the background at 0:34? Is that a sheepdog? Thank you for your videos!
UK has little to none trees... Be they have been cut for ship construction and buildings, and then the weather is such that you don't get so much forests anyways naturally.
@@Farlig69 And what was rubbish that I said? 1) The UK use to have lot of trees. 2) The people cut the trees for various reasons (main ones firewood and shipbuilding). 3) The UK weather is such that after major deforestation, the trees can't anymore grow naturally, and even plantations fail. That is like Iceland, from 35% of forests cut down to less than 1% and so has it been, because when you have fully flat and open ground, you don't get trees easily growing there anymore. Look at the historic numbers: 1086 the UK surface 15% was covered by trees. 1870 only 4,8% of the UK was covered in trees. 1980 the coverage was 7% for trees. 2000 the coverage was 8,4% for trees. 2020 the coverage is about 13% for trees. Here, it is 75% and has been for centuries. And yet, EU come here to teach how to maintain forest, this in country that has cut down all its trees twice in the last 80 years... This is because the system to maintain the ecology is best in the whole world.
Stumbled over your channel yesterday! Good informative videos! Thank you very much. About the Azimuth vs bearing movie I have two questions. A) at around 5:40-5:50 you show two lines: what is the reason for having zero degrees on the left hand side on the first line and zero degrees at the right side for the second line? B) Using an Azimuth and your example with the wall, you would also need to know what side of the wall you are, wouldn't you? Or have I misunderstand the whole thing?
It was to show that 0 can be at either end of the meridian, it's up to the user to decide which. You're right about the wall. Again it's up to the user to decide with is 0 and which is 180. THIS is the reason (as I say in the video) that it is normal to use the north/south line on a compass as the meridian as this get's rid of any confusion.
I now understand the difference better. Please register and change the Wikipedia definition. When everyone in there own area of competence improves on Wiki the accuracy of information available to all increases.
As a Mariner, and practitioner of Celestial Navigation: An azimuth is something that is calculated, something that is true, something that is, or has been, or will be. Something that is fact. A bearing is something that is measured, using a compass (or gyro-compass repeater on the bridge or bridge wing). Something that is apparent. Once per watch, when celestial objects are visible, we can use a compass (or repeater) to take a bearing. Compare that bearing with what the calculated azimuth is. The difference, if any, between the two, is our recorded "compass error". The difference between the azimuth and the gyro repeaters should be minimal (fractions of a degree). The difference between azimuth and the magnetic compass can be significant at times (I've see up to 15° difference in the seas around southern Africa). The latter can be caused by Variation (what terrestrial navigators call "declination"), and/or Deviation (the effects of the ship's own magnetic field and, particularly on Containerships, the magnetic fields of the cargo). Bearings of other vessels are used for collision avoidance decisions. Bearings of fixed objects can be used to fix a vessel's position (a Three Point Fix). Bearings are relative to North and are given in three figure notation (e.g. 090°, zero-nine-zero and NOT 90, ninety). Bearings relative to the ship are referred to as Relative Bearings and are relative to the ship's head. or her beam (port or starboard beam), or simply "dead ahead" or "dead astern". They can be given in degrees (up to 90°) or "points" (1 point = 11.25°). ☀🌕⭐🚢🧭
This video was really helpful to me -- particularly where you inserted the diagrams... more than anything, they helped me to feel that I'd caught up with your running narrative.
Thanks for this. Many original definitions these days get lost because of carelessness. Inflation is another example that used to mean increase in money supply, these days it means the increase in cost of living and that is now also being diluted to exclude food and energy prices from "inflation". BTW. AI (or google or wikipedia) is NOT artificial and definitely NOT intelligent. Buy old dictionaries, like Encyclopædia Britannica fourteenth edition, old school is still around but not for long... Build your own Library of Alexandria let your kids inherit, your descendants will thank you for it.
Definitions change in specific fields or specific circumstances or words are adapted for other purposes. Doesn't mean that they are lost or diluted. Words have different meanings in different contexts and of course words and use of words changes, because things change. There's also different ways of meassuring inflation, different price indeces etc. Try calculating such stuff yourself, you'll notice very quickly that you'll have to use a very specific set of parameters, or else you just cannot accurately compare. Sometimes such things are influenced by lobbyist groups, politicians or wealthy individuals, sometimea it's just a better, more accurate way to do. Change isn't inherently bad. Some words or marketing buzz, for instance the use of AI when it's mostly machine learning algorithms. Sometimes AI is correctly used, though. Btw, I can still find tons of articles that mention increase in money supply as one driving force of inflation.
Yes. Although most people, when out walking, will use N/S line as their azimuth. Of course on construction sites, forestry management, etc people will make their own azimuth
Honestly, the ones I get confused are bearing and heading. That might just be a US/UK difference. Heading is the direction one is going, bearing is the angle from your heading to an object of interest.
Ok, I am a bit confused about this. I have always used Bearings from my time in the ACF and the big mans army. I like this explanation of using a prime meridium to then take an azimuth from and the bearing being from your point. But I can not find any papers or examples that match your explanation. could you give references for this as it seems that all literature to this is stating that Azimuth and Bearing are now an interchangeable word for the same meaning of taking a line of travel or direction in reference to North in a clockwise direction from your point. Looking at the root of the word Azimuth coming from medieval Arabic meaning direction could be why most use it instead of bearing. As our American friends use it instead of bearing and that youTube is dominated by US based films that give navigation training then I can see why. But as you state as long as all in the group are working on the same method or termanology IE Bearing or Azimuth and this is stated in the safety brief then all should be fine. I do like @TheUnorthodoxy explanation on this. Swampy
Hi Peter, it could be either so maybe this is where the confusion may have started.. This is why it is common to use the N/S line as the azimuth. But of course the 0 - 180 azimuth line can be in any direction. As an example if you are surveying a new construction site then you may choose the line of any nearby roads, current services (e.g. gas pipes, main electricity feeds, drainage, etc) or on a greenfield site the initial surveyor could just draw a line and that would be the azimuth for all future plans.
@@TheMapReadingCompany Thanks for your reply. To give instructions then, one would have to specify in which direction one should turn upon reaching the azimuth?
I wonder if you can help.? Many years ago I had a Silva Base Plate compass that had a small prism set into the side of it. This allowed you to view the degrees shown, when taking a bearing, down to at least 1/2 degree. It was very much like what could be obtained from a "Plastimo Marine hand bearing compass". Do you know if these Silva compasses are still made.?
I think you're asking about the Silva 54. You could contact Silva and ask for a reputable supplier. There are lots for sale on Amazon but be careful if you order one. Make sure its genuine and in degrees, if that's what you're looking for
Sounds like Azimuth would be (or is) useful without a compass in a landscape with good landmarks. On a cloudy day, it is easier to estimate 45° from a clear line in the landscape than, for example, SSE.
All new to me. Thank you. However. Surely you need to define the direction of the Meridian prior to the Azimuth? Otherwise you could, potentially, be going 180° to your intention. If the Meridian is heading SW to NE (bearing 45°) then an Azimuth of 90° would be a heading SE (bearing 135°). If the Meridian is heading NE to SW (bearing 225°) then an Azimuth of 90° would be a heading NW (bearing 315°). Am I wrong? This would concur with @TheUnorthodoxy comment. This would also explain why having a S to N Meridian is so commonly used.
You're right. In navigation a standard azimuth isn't much use - it's mainly surveyor's etc which use them. The North South meridian is the normally used as the meridian when using a compass so the direction is the same as a bearing.
So, if the azimuth is taken from the north-south line, with north zero degrees and south being 180 degrees, does it have a minimum of zero degrees and a maximum of 180 degrees only? Otherwise, the azimuth can be taken from the south-north line, with zero being south, north being 180 degrees. If it can be 360 degrees, with north being zero (or 360 degrees) and south 180 degrees constantly, then, is it not the same as a bearing? In surveying, I was taught the azimuth is an elevation, or, 10 degrees uphill for example, which by taking the azimuth of the north star (Polaris), we determine latitude. North star at 45 degrees azimuth means you are at 45 degrees latitude.
The instruments used to observe that angle would be aligned with local gravity (plumbline) and that 10° in your example sounds more like an altitude (90° - zenith angle) rather than an azimuth; however, I don't have much knowledge of astronomical observations in surveying. Aligning your north to Polaris and turning a horizontal angle (say 45°) is considered an astronomical azimuth (or star shot).
Anybody else concerned about the dog worrying sheep on the hill in the background? Seriously though. In maths and physics, East is zero and angles increase in an anticlockwise direction. It could hardly be more different. Now azimuth. This term is used in astronomy in conjunction with elevation for pointing some kinds of telescope. In astronomy due South is zero and the angle increases to the West. The stars themselves are positioned by right ascension and declination. No wonder these terms have got confused.
At 5:00 you say azimuth is taken in a clockwise rotation from a meridan (the wall) but at 0:16 you say an azimuth of 160 and walk to your left (viewer's right) which means you've gone anticlockwise from the wall - or am I misunderstanding something?
im not sure youre correct.. in aviation, naval, astronomy and surveying... What is the difference between azimuth and heading? The word is relative bearing, a bearing relative to your heading. Azimuth is a bearing relative to North . An azimuth is a type of bearing. turn 30 degree azimuth east from north of your current position.. A bearing is relative to your direction of travel.. bear left , bear right,,, bear left 30 degrees from your heading of 200 degrees southwest
Hi Johnny Thanks for joining the conversation. I must admit that I know very little about astronomy, surveying, geology, etc. Although I recognise that many different fields use the same words with different meanings and the same things are discribed using different words in different counties (Yard / Garden - Flat / Apartment - Cot / Crib, etc, etc, etc, 😊) The word bearing has many meanings. In the UK and much of the world, in a navigation sense, a bearing is commonly used to describe the direction from somewhere to somewhere else using degrees. A bearing is not relative to your position or heading (as I assume that neither of us are in the hymalayas at the moment). As an example from the summit of Everest the summit of Lhotse is at a bearing of (approx.) 168 degrees. When talking about navigation, using a hand held compass, the word azimuth means a clockwise angle from a meridian (line). As this line can be in any direction (e.g. the wall in the video) it is normal to use the North/South “line” as the meridian and so the angles (from the line) would be the same as a compass bearing.
Thank you for your videos. I find them very entertaining, however youur explanation about the azimuth is not correct. It always refers to the north. @@TheMapReadingCompany
It all depends on context. In the merchant navy we have many different types of methods of describing direction. True Bearing: the clockwise angle from True North, i.e. east is 090 and west is 270. Gyro bearing (similar but referenced to the gyrocompass north which should be the same as True North but will inevitably have some small error) Magnetic Bearing: same but referenced to Magnetic North which isn't the same as True North unless variation is 0 at your location Compass North: same but referenced to the north which your magnetic compass points to, which should be the same as magnetic north but isn't because of an error known as deviation. Relative Bearing: clockwise angle from the vessels head (right ahead is 000 and dead astern is 180, abeam to port is 270) Points: 32 points in a whole circle, can be used as compass directions or as a system of relative direction (steer NW by W, or look 2 points to starboard) Azimuth: angle from a true meridian (N/S) in an E/W direction (e.g. N 65 W would equate to a true bearing of 295) Amplitude: angle from E/W in a N/S direction (e.g. E 05 N would be a true bearing of 085) We use True/Gyro/Compass Bearings for courses to steer, position fixing, indicating the direction of an object of interest or assessing risk of collision. Relative bearings are used for indicating the direction of an object, assessing risk of collision (if your heading doesn't change) and some basic navigation tricks (e.g. double angle on the bow). Azimuths and Amplitudes are used for celestial navigation. Everyone has their own jargon and the same jargon can mean different things in different industries or even sectors of the same industry
Difference between absolute and relative angles. Bearing is absolute based upon fixed zero (north) whereas azimuth is an angle from anything you say is your zero datum - wall, stream, etc. i.e. relative angle…
I am highly skeptical of your usage of _meridian_ as _any_ horizontal reference direction. This must be a rather niche or local usage, and I'm afraid in an outdoors teaching context it can be quite literally misleading, perhaps even dangerous. Could this usage have arisen from a misunderstanding within the group you learned from? The word 'meridian' derives from Latin for literally 'mid day' and in context of the sun refers to South in particular, at least in the hemisphere where Latin was historically used. While etymology is not dispositive, people in science and engineering fields(*) will understand 'meridian' in the geographic sense of a North-South line on the earth's or other celestial body's surface, and by extension the plane spanned by this line and the local vertical to the zenith. Given the above, _azimuth_ is generally understood as horizontal angle reckoned North over East, unless explicitly specified in some fields, as you mentioned. Basis: I have a long-time hobbyist interest in astronomy, military and civilian cartography, and surveying. (*) Acupuncture excluded, by definition.
Hi, thanks for joining the conversation. A meridian can be any line in any direction you need it to be - my dad was a site surveyor and never bothered asking which “direction” the meridian was. He just looked at the site plan and draw the most obvious line. After that was drawn it was basically set in stone as the line from which all other horizontal angles were taken. But, as said in the video this isn’t much use when navigating around the hills, which is all I’m really interested in. This is why we tend use the N/S line as our meridian. Obviously in different fields such as geology, astronomy, engineering, etc, etc they will use different meridians. In my line of work we use the direction from N to S - or we’d all end up walking around all over the place.
This is desperately confusing to anyone who has been involved in surveying. The "meridian" for example is commonly defined to designate a great circle that passes through the geographic poles. All geographic meridian converge at the two poles and are at their widest separation at the equator. The "M" in AM and PM stands for "Meridian," and refers to the position of the sun at solar noon on the part of the planet you are standing or floating one, or flying above. Meridians are not arbitrary. Similarly, "bearing" is a direction of traverse or sighting. The basic practice divides the compass into quadrants. It measures a direction relative to a fixed reference as an angle looking in the direction necessary to travel to reach a location _from_ the position where the bearing was taken (azimuths serve just as well for this and are subject to less recording error). You see the common use of bearings in survey plats, where the surveyor records the direction and distance of travel for traverses. A clockwise series of traverses might begin N _ deg. W. 500 meters, N _ deg. E. 200 meters, S _ deg. E., etc. Bearings never have a degree value greater than 90 degrees. You can find definitions and explanations in sources such as Surveying by Charles B. Breed. Azimuths number on a compass from 1 degree to 360 degrees clockwise around the compass circle. You can buy compasses marked in either quadrant (used for bearing-reading formats) or azimuth. The military (US or British) typically divides compasses into quadrants (NE, SE, SW, and NW).
No. An azimuth is a direction from a point on a meridian. Normally the meridian used is the North (0)/South (180) direction, but it can be in any direction.
Are people getting this wrong still. We kearn thus id cubs! Btw im also ex military so get both aspects. It couldnt more simple. Obviuosly you dont need me to say your correct. Back in the day before intercrap we relied in peolle like you fir kniwledge its about time we reverted back
I'm a veteran of the British Army (royal tank regiment), and keen hill walker.
The use of an azimuth is when you know where you have travelled and recorded your bearing and/or azimuth changes.
I often go for walks with no destination set at the outset. The point is to walk and pick a direction and head in that direction until it intersects with something (my new meridian).
So, if we were using your wall (meridian) yes we could pick any point for us to make up an azimuth to head along, and we could end up in any place parallel to each other uf the wall was straight like diagonal chevrons painted on the back of a highways vehicle.
However if you use a distinguishable point along the wall ie a stile, a gate, a sign or even a broken part if the wall or tree something describable and identifiable you can record that as I do and look about find a direction and take an azimuth reading from my (locator along my meridian).
If anyone was needing to come to my location say I'm injured and called for mountain rescue, I can lead them along my azimuth to key meridian landmarks ie stile, gate sign tree broken wall etc and the azimuth from that locator.
So azimuth does work provided the locator along the meridian is distinguishable to make the azimuth accurate to lead in the correct direction but azimuth only work if you are following directions and not just wandering aimlessly and then the search team are using an azimuth to find uou, they only work if you first record your azimuth from the first key locator (your car hotel bus/train stop cafe etc). Then every direction change is recorded so I take an azimuth of 143 and meet your wall, I record the 143 azimuth from my cars rear bumper facing across the road out of the carpark. When I meet your wall I turn east along the south side of the wall and walk 300m until I meet the stone stile, I then take an azimuth of 40 and follow to my accident in a field 240m from the wall in a depression.
So azimuth can and are used effectively and provided they are recorded accurately as you go, they can save your life if rescue is needed.
Even if I'm not on an azimuth trail (wandering about lol) I still record my headings and distances and landmarks from departure to my current location, just incase I'm injured and need to get rescue to me. They ain't spending two days searching they know exactly where to find me before they even leave the offices.
If I could advise anyone if anything that would be my advice. Record every direction turn landmarks and distance /timing you can in as much detail as you can, the more accurate, the faster help gets to you.
Happy walking
All good points. Thanks for joining thr conversation.
That answers my question how to know which direction of the wall or rather meridian is azimuth zero.
For added confusion, you could address 'yaw'; the difference between the direction you're pointing and the actual direction of travel. For maritime purposes, azimuth is relative to the ships centreline running through the bow.
Superb. Just a tiny correction about military navigation, we used mils in my day both on our prismatic (lensatic?) compass and for eg. mortar plotting. 6400 miles to a circle. Brilliant video btw. I can’t recall using a baseplate compass. Ironic term since the mortar has a baseplate. But I can’t imagine a baseplate compass, which is all most people ever need, in mils.
Well, we can blame ship navigators for this (I think) because that's where the difference between the two terms is most important. Azimuth is just an angle relative to the ship, with 0 being straight ahead. And this leads to the best description I know: bearings are measured relative to North, azimuths are measured relative to any other direction.
It's relevant in surveying as well.
Your last sentence there really cleared it up for me. Thanks!
Many thanks. I’ve taught civilian navigation for years and always wondered what ex military folks were talking about. Now I know! (I’ll still only use bearings from the north though 😂)
Such an interesting channel, a treasure of information. Greetings from Romania and thank you for the dedicated work you are doing!
This is something completely new to me. Never heard of it, seen it or used it before. It is interesting to know, but I will probably never use it. It could be too confusing for the local scout group to whom I occasionally teach some map and compass techniques.
The military system N46°E mentioned here is well known to me, but is also never used. I limit myself to the 360° right-turning system.
Of course, I will try to remember this in case I ever have to deal with it.
Thank you for explaining this to us. A valuable contribution.
Yet another video clearing up the fog of misconceptions provided by the internet! Thank you very much, always a pleasure to learn from you.
a video provided by.... the internet 🤯😂
Very interesting lecture for the first time I hear azimuth and versus Bearing. I have always used azimuth as going in a given direction without a compass just in the direction to go in the same direction using the nature of the sun or other signs. It is close to your explanation.
Hmmmm . . . I learned navigation in the US Navy. What you are calling "bearing", I'd call "heading." Heading is an angle relative to North, usually true North. So when the captain wants to know what direction the ship is going, he asks for the heading.
Bearing is relative to an arbitrary datum line, usually the centerline of the ship. So the direction to a lighthouse would be given relative to the ship. "What's the bearing of the lightshoue?" 90 degrees! Which would put it off the starboard side.
These terms were also in use in civil aviation when I learned to fly.
Well explained Wayne. I'm sticking to bearings - ! 😅
Thanks. :) I feel a sense of dread when things like this happen... It seems there's no good way to handle mass misconceptions. I appreciate that you've provided a way to know the truth in creating this video.
Thank you for the video, not to forget, that an azimuth take from a Grid North, on a map and a Bearing measured from Magnetic North, with a sighting compass, may have a declination error between them..
Thank you for the explanation, I didn't know about the difference.
In engineering field, azimuth is just one of the angles that define a spherical coordinate system. The meridian can be thought as one of the coordinate axes and the azimuth is just one of the two angles that define a space direction (azimuth and elevation). I guess that the problem is that someone gave to azimuth a "magnetic property" while it is instead just an angle with respect to a specific frame of reference (the meridian in your example). On the other hand, bearing lives in the navigation field and its an angle that is related to the magnetic north.
Bloody interesting!!! I have just discovered this channel. I wish I had known this when I was a scout :)
Thanks for watching the videos
I once had a person reading a legal description of land. Each leg of the description started with the direction “thence run..followed by the bearing of degrees, minutes and seconds. This person asked me how fast they should run.
Thnks coach... well defined ... a child could understand it too
Enjoying your videos. Thank you.
That is very well explained! thank you for sharing
I am not so dumb as people think, 😇 I had a good idea what an azimuth was; We use to use it in the repair and alignment of old tube radios and new it was to do with angles and can be checked with a protractor. 😋. thank you Mr Map Man
always worth watching
That distinction might be handy close to the poles. If you are at a base located at the south pole all bearings and meridians on the globe converge under your feet. Using a local meridian that is identifiable might work better at local navigation around the environs of your base. Perhaps a fence line around the perimeter of the installation.
Brilliant content! Thanks so much
I thought that I was differentiating bearings vs azimuths, but really the explanation below only differentiates grid bearings/azimuths (on a mapping plane) from true bearings/azimuths.
From a background in surveying, these are two characteristics that differentiate my understanding of bearings vs azimuths:
The first characteristic of an azimuth is that an azimuth changes as you move along the line whereas a bearing will remain constant from beginning to end.
The line shown at 5:15 is referenced in my explanation. Whether it is an astronomic, magnetic, or geodetic azimuth they all reference a northernly point from which a local meridian is created (from the observer to the magnetic north pole in this example); however, as you move along the line (in red) and take another observation a new local meridian will be created that is not parallel with the previous local meridian but still considered to be 0° along this new meridian. The result is that the exact same line (in red) now will be a different azimuth than what was observed at the previous starting location (somewhere). The difference will be negligible for walking distances but if we are travelling a long distance then the magnetic azimuth will noticeably change (and this change is not to be confused with greater circles and rhumb lines/loxodromes in mapping projections.
The second characteristic is that back-bearings (reverse bearings) of a bearing are a simple calculation: for example, 45° forward from somewhere will be (45° + 180°) 225° backwards from somewhere else. Direct and inverse azimuths are not computed as easily.
Because azimuths are all converging to a central point (in this case the Magnetic North Pole), spherical trigonometry is used to calculate the direct and inverse azimuth.
I think the video explains azimuths well from a navigational standpoint they are referencing a meridian and turn in a clockwise rotation.
By the way, in surveying we call your military bearings 'quadrant bearings' (S60E), and confusingly your civilian bearings 'azimuths' haha, which is why I like to call them 'full-circle bearings' (240°).
note: 'grid bearings' are also a good term for your civilian bearings.
I love you channel. I just say RUclips turned off comments for your trig point video. I have no idea why. I commented on it a while ago - it was brilliant.
Greetings from Brazil. As a radio amateur (PU5YUR), ex boyscout and ex army corporal I have recently regained interest in analog navigation and have to say yours are the best videos available on the subject.
I have two unrelated questions though.
From your videos and from a recent trip to London, I noticed that your landscape always seems to have been recently mowed 😊. I can't imagine traveling to the countryside in my country without being instantly surrounded by thick vegetation so I have the false feeling that it would be almost impossible to get lost in the UK. How can there be so few trees around there?
The other question is: what's that dark animal chasing the sheep in the background at 0:34? Is that a sheepdog?
Thank you for your videos!
Animals (sheep, cows, deer, etc) keep the grass short in many areas. Where there are no animals, very soon we have a new forest.
UK has little to none trees... Be they have been cut for ship construction and buildings, and then the weather is such that you don't get so much forests anyways naturally.
@@paristo Rubbish, just look at Scandinavia... Britain used to be covered in trees, but it's been massively deforested by mankind.
@@Farlig69 And what was rubbish that I said?
1) The UK use to have lot of trees.
2) The people cut the trees for various reasons (main ones firewood and shipbuilding).
3) The UK weather is such that after major deforestation, the trees can't anymore grow naturally, and even plantations fail.
That is like Iceland, from 35% of forests cut down to less than 1% and so has it been, because when you have fully flat and open ground, you don't get trees easily growing there anymore.
Look at the historic numbers:
1086 the UK surface 15% was covered by trees.
1870 only 4,8% of the UK was covered in trees.
1980 the coverage was 7% for trees.
2000 the coverage was 8,4% for trees.
2020 the coverage is about 13% for trees.
Here, it is 75% and has been for centuries. And yet, EU come here to teach how to maintain forest, this in country that has cut down all its trees twice in the last 80 years... This is because the system to maintain the ecology is best in the whole world.
Stumbled over your channel yesterday! Good informative videos! Thank you very much. About the Azimuth vs bearing movie I have two questions. A) at around 5:40-5:50 you show two lines: what is the reason for having zero degrees on the left hand side on the first line and zero degrees at the right side for the second line? B) Using an Azimuth and your example with the wall, you would also need to know what side of the wall you are, wouldn't you? Or have I misunderstand the whole thing?
It was to show that 0 can be at either end of the meridian, it's up to the user to decide which.
You're right about the wall. Again it's up to the user to decide with is 0 and which is 180.
THIS is the reason (as I say in the video) that it is normal to use the north/south line on a compass as the meridian as this get's rid of any confusion.
@@TheMapReadingCompany You could (almost) say that the directions right and left is a very rough version of azimuth?
I now understand the difference better. Please register and change the Wikipedia definition. When everyone in there own area of competence improves on Wiki the accuracy of information available to all increases.
Life's too short for plain biscuits, it’s also too short to worry about what wiki says about anything.
As a Mariner, and practitioner of Celestial Navigation:
An azimuth is something that is calculated, something that is true, something that is, or has been, or will be. Something that is fact.
A bearing is something that is measured, using a compass (or gyro-compass repeater on the bridge or bridge wing). Something that is apparent.
Once per watch, when celestial objects are visible, we can use a compass (or repeater) to take a bearing. Compare that bearing with what the calculated azimuth is. The difference, if any, between the two, is our recorded "compass error".
The difference between the azimuth and the gyro repeaters should be minimal (fractions of a degree). The difference between azimuth and the magnetic compass can be significant at times (I've see up to 15° difference in the seas around southern Africa). The latter can be caused by Variation (what terrestrial navigators call "declination"), and/or Deviation (the effects of the ship's own magnetic field and, particularly on Containerships, the magnetic fields of the cargo).
Bearings of other vessels are used for collision avoidance decisions. Bearings of fixed objects can be used to fix a vessel's position (a Three Point Fix). Bearings are relative to North and are given in three figure notation (e.g. 090°, zero-nine-zero and NOT 90, ninety).
Bearings relative to the ship are referred to as Relative Bearings and are relative to the ship's head. or her beam (port or starboard beam), or simply "dead ahead" or "dead astern". They can be given in degrees (up to 90°) or "points" (1 point = 11.25°).
☀🌕⭐🚢🧭
This video was really helpful to me -- particularly where you inserted the diagrams... more than anything, they helped me to feel that I'd caught up with your running narrative.
Got it. Thought they were the same. Seem to use Azimuths more in the US. UK uses bearings. Thanks for clearing this up.
Do you have any references to back up your definition? It makes sense to me but as you said, searching can muddle the real answer. Thanks.
Brilliant!
Thanks for this. Many original definitions these days get lost because of carelessness. Inflation is another example that used to mean increase in money supply, these days it means the increase in cost of living and that is now also being diluted to exclude food and energy prices from "inflation". BTW. AI (or google or wikipedia) is NOT artificial and definitely NOT intelligent. Buy old dictionaries, like Encyclopædia Britannica fourteenth edition, old school is still around but not for long... Build your own Library of Alexandria let your kids inherit, your descendants will thank you for it.
Definitions change in specific fields or specific circumstances or words are adapted for other purposes. Doesn't mean that they are lost or diluted. Words have different meanings in different contexts and of course words and use of words changes, because things change. There's also different ways of meassuring inflation, different price indeces etc. Try calculating such stuff yourself, you'll notice very quickly that you'll have to use a very specific set of parameters, or else you just cannot accurately compare.
Sometimes such things are influenced by lobbyist groups, politicians or wealthy individuals, sometimea it's just a better, more accurate way to do. Change isn't inherently bad.
Some words or marketing buzz, for instance the use of AI when it's mostly machine learning algorithms. Sometimes AI is correctly used, though.
Btw, I can still find tons of articles that mention increase in money supply as one driving force of inflation.
So does that mean that azimuth uses any point of reference including north, but bearings uses strictly north?
Yes. Although most people, when out walking, will use N/S line as their azimuth.
Of course on construction sites, forestry management, etc people will make their own azimuth
A big thanks...
Honestly, the ones I get confused are bearing and heading. That might just be a US/UK difference. Heading is the direction one is going, bearing is the angle from your heading to an object of interest.
Heading is the general direction of travel.
Bearing is the rotational angle with relation to North
Ok, I am a bit confused about this. I have always used Bearings from my time in the ACF and the big mans army. I like this explanation of using a prime meridium to then take an azimuth from and the bearing being from your point. But I can not find any papers or examples that match your explanation. could you give references for this as it seems that all literature to this is stating that Azimuth and Bearing are now an interchangeable word for the same meaning of taking a line of travel or direction in reference to North in a clockwise direction from your point.
Looking at the root of the word Azimuth coming from medieval Arabic meaning direction could be why most use it instead of bearing. As our American friends use it instead of bearing and that youTube is dominated by US based films that give navigation training then I can see why. But as you state as long as all in the group are working on the same method or termanology IE Bearing or Azimuth and this is stated in the safety brief then all should be fine.
I do like @TheUnorthodoxy explanation on this.
Swampy
Which end of the wall in your example is 0 and which is 180 and why?
Hi Peter, it could be either so maybe this is where the confusion may have started.. This is why it is common to use the N/S line as the azimuth.
But of course the 0 - 180 azimuth line can be in any direction. As an example if you are surveying a new construction site then you may choose the line of any nearby roads, current services (e.g. gas pipes, main electricity feeds, drainage, etc) or on a greenfield site the initial surveyor could just draw a line and that would be the azimuth for all future plans.
@@TheMapReadingCompany Thanks for your reply. To give instructions then, one would have to specify in which direction one should turn upon reaching the azimuth?
I wonder if you can help.?
Many years ago I had a Silva Base Plate compass that had a small prism set into the side of it.
This allowed you to view the degrees shown, when taking a bearing, down to at least 1/2 degree.
It was very much like what could be obtained from a "Plastimo Marine hand bearing compass".
Do you know if these Silva compasses are still made.?
I think you're asking about the Silva 54. You could contact Silva and ask for a reputable supplier.
There are lots for sale on Amazon but be careful if you order one. Make sure its genuine and in degrees, if that's what you're looking for
Sounds like Azimuth would be (or is) useful without a compass in a landscape with good landmarks. On a cloudy day, it is easier to estimate 45° from a clear line in the landscape than, for example, SSE.
All new to me. Thank you.
However. Surely you need to define the direction of the Meridian prior to the Azimuth? Otherwise you could, potentially, be going 180° to your intention.
If the Meridian is heading SW to NE (bearing 45°) then an Azimuth of 90° would be a heading SE (bearing 135°).
If the Meridian is heading NE to SW (bearing 225°) then an Azimuth of 90° would be a heading NW (bearing 315°).
Am I wrong?
This would concur with @TheUnorthodoxy comment.
This would also explain why having a S to N Meridian is so commonly used.
You're right. In navigation a standard azimuth isn't much use - it's mainly surveyor's etc which use them.
The North South meridian is the normally used as the meridian when using a compass so the direction is the same as a bearing.
So an Azimuth is relative (akin to 11 o clock, 12 o clock, 13 o clock)
And Bearing is fixed wrt magnetic north / true north
So, if the azimuth is taken from the north-south line, with north zero degrees and south being 180 degrees, does it have a minimum of zero degrees and a maximum of 180 degrees only? Otherwise, the azimuth can be taken from the south-north line, with zero being south, north being 180 degrees. If it can be 360 degrees, with north being zero (or 360 degrees) and south 180 degrees constantly, then, is it not the same as a bearing? In surveying, I was taught the azimuth is an elevation, or, 10 degrees uphill for example, which by taking the azimuth of the north star (Polaris), we determine latitude. North star at 45 degrees azimuth means you are at 45 degrees latitude.
The instruments used to observe that angle would be aligned with local gravity (plumbline) and that 10° in your example sounds more like an altitude (90° - zenith angle) rather than an azimuth; however, I don't have much knowledge of astronomical observations in surveying.
Aligning your north to Polaris and turning a horizontal angle (say 45°) is considered an astronomical azimuth (or star shot).
Anybody else concerned about the dog worrying sheep on the hill in the background? Seriously though. In maths and physics, East is zero and angles increase in an anticlockwise direction. It could hardly be more different. Now azimuth. This term is used in astronomy in conjunction with elevation for pointing some kinds of telescope. In astronomy due South is zero and the angle increases to the West. The stars themselves are positioned by right ascension and declination. No wonder these terms have got confused.
Yes, I noticed the dog worrying sheep. 😲
At 5:00 you say azimuth is taken in a clockwise rotation from a meridan (the wall) but at 0:16 you say an azimuth of 160 and walk to your left (viewer's right) which means you've gone anticlockwise from the wall - or am I misunderstanding something?
I'll stick to bearing, I use Azimuths for subsea pipelines and tie-in spool engineering.
im not sure youre correct.. in aviation, naval, astronomy and surveying... What is the difference between azimuth and heading?
The word is relative bearing, a bearing relative to your heading. Azimuth is a bearing relative to North . An azimuth is a type of bearing. turn 30 degree azimuth east from north of your current position..
A bearing is relative to your direction of travel.. bear left , bear right,,, bear left 30 degrees from your heading of 200 degrees southwest
Hi Johnny
Thanks for joining the conversation. I must admit that I know very little about astronomy, surveying, geology, etc. Although I recognise that many different fields use the same words with different meanings and the same things are discribed using different words in different counties (Yard / Garden - Flat / Apartment - Cot / Crib, etc, etc, etc, 😊)
The word bearing has many meanings. In the UK and much of the world, in a navigation sense, a bearing is commonly used to describe the direction from somewhere to somewhere else using degrees.
A bearing is not relative to your position or heading (as I assume that neither of us are in the hymalayas at the moment). As an example from the summit of Everest the summit of Lhotse is at a bearing of (approx.) 168 degrees.
When talking about navigation, using a hand held compass, the word azimuth means a clockwise angle from a meridian (line). As this line can be in any direction (e.g. the wall in the video) it is normal to use the North/South “line” as the meridian and so the angles (from the line) would be the same as a compass bearing.
Thank you for your videos. I find them very entertaining, however youur explanation about the azimuth is not correct. It always refers to the north. @@TheMapReadingCompany
It all depends on context. In the merchant navy we have many different types of methods of describing direction.
True Bearing: the clockwise angle from True North, i.e. east is 090 and west is 270.
Gyro bearing (similar but referenced to the gyrocompass north which should be the same as True North but will inevitably have some small error)
Magnetic Bearing: same but referenced to Magnetic North which isn't the same as True North unless variation is 0 at your location
Compass North: same but referenced to the north which your magnetic compass points to, which should be the same as magnetic north but isn't because of an error known as deviation.
Relative Bearing: clockwise angle from the vessels head (right ahead is 000 and dead astern is 180, abeam to port is 270)
Points: 32 points in a whole circle, can be used as compass directions or as a system of relative direction (steer NW by W, or look 2 points to starboard)
Azimuth: angle from a true meridian (N/S) in an E/W direction (e.g. N 65 W would equate to a true bearing of 295)
Amplitude: angle from E/W in a N/S direction (e.g. E 05 N would be a true bearing of 085)
We use True/Gyro/Compass Bearings for courses to steer, position fixing, indicating the direction of an object of interest or assessing risk of collision. Relative bearings are used for indicating the direction of an object, assessing risk of collision (if your heading doesn't change) and some basic navigation tricks (e.g. double angle on the bow).
Azimuths and Amplitudes are used for celestial navigation.
Everyone has their own jargon and the same jargon can mean different things in different industries or even sectors of the same industry
I’m seriously stupid. I’ll now rewatch 20 or so times😅😅😅
correct me if im worng but allways thought an azmith is an object directly overhead of your position on earth.
Gerard.
The word you are looking for is zenith.🤓
wikipedia is open to anyone to update so you could correct it
Most rivers aren’t perfectly straight.
Right.
Difference between absolute and relative angles. Bearing is absolute based upon fixed zero (north) whereas azimuth is an angle from anything you say is your zero datum - wall, stream, etc. i.e. relative angle…
I am highly skeptical of your usage of _meridian_ as _any_ horizontal reference direction. This must be a rather niche or local usage, and I'm afraid in an outdoors teaching context it can be quite literally misleading, perhaps even dangerous. Could this usage have arisen from a misunderstanding within the group you learned from?
The word 'meridian' derives from Latin for literally 'mid day' and in context of the sun refers to South in particular, at least in the hemisphere where Latin was historically used. While etymology is not dispositive, people in science and engineering fields(*) will understand 'meridian' in the geographic sense of a North-South line on the earth's or other celestial body's surface, and by extension the plane spanned by this line and the local vertical to the zenith.
Given the above, _azimuth_ is generally understood as horizontal angle reckoned North over East, unless explicitly specified in some fields, as you mentioned.
Basis: I have a long-time hobbyist interest in astronomy, military and civilian cartography, and surveying.
(*) Acupuncture excluded, by definition.
Hi, thanks for joining the conversation. A meridian can be any line in any direction you need it to be - my dad was a site surveyor and never bothered asking which “direction” the meridian was. He just looked at the site plan and draw the most obvious line. After that was drawn it was basically set in stone as the line from which all other horizontal angles were taken.
But, as said in the video this isn’t much use when navigating around the hills, which is all I’m really interested in. This is why we tend use the N/S line as our meridian.
Obviously in different fields such as geology, astronomy, engineering, etc, etc they will use different meridians. In my line of work we use the direction from N to S - or we’d all end up walking around all over the place.
This is desperately confusing to anyone who has been involved in surveying. The "meridian" for example is commonly defined to designate a great circle that passes through the geographic poles. All geographic meridian converge at the two poles and are at their widest separation at the equator. The "M" in AM and PM stands for "Meridian," and refers to the position of the sun at solar noon on the part of the planet you are standing or floating one, or flying above. Meridians are not arbitrary.
Similarly, "bearing" is a direction of traverse or sighting. The basic practice divides the compass into quadrants. It measures a direction relative to a fixed reference as an angle looking in the direction necessary to travel to reach a location _from_ the position where the bearing was taken (azimuths serve just as well for this and are subject to less recording error). You see the common use of bearings in survey plats, where the surveyor records the direction and distance of travel for traverses. A clockwise series of traverses might begin N _ deg. W. 500 meters, N _ deg. E. 200 meters, S _ deg. E., etc. Bearings never have a degree value greater than 90 degrees. You can find definitions and explanations in sources such as Surveying by Charles B. Breed.
Azimuths number on a compass from 1 degree to 360 degrees clockwise around the compass circle. You can buy compasses marked in either quadrant (used for bearing-reading formats) or azimuth. The military (US or British) typically divides compasses into quadrants (NE, SE, SW, and NW).
So in a layman language Azimuth is the destination eh?
No. An azimuth is a direction from a point on a meridian. Normally the meridian used is the North (0)/South (180) direction, but it can be in any direction.
I see the people on the hill in the back ground allowing their dog to chase the sheep. I don't know the bearing,
I uploaded a zoomed in copy of that bit to another forum. Let's just say those two people didn't much sympathy
Are people getting this wrong still. We kearn thus id cubs! Btw im also ex military so get both aspects. It couldnt more simple. Obviuosly you dont need me to say your correct. Back in the day before intercrap we relied in peolle like you fir kniwledge its about time we reverted back
You make sense to with an anstronomy training. You can make updates to Wikipedia!
Ignorance was bliss! I’m going to try to forget this bit of information as it has no relevance to my use of map and compass…or does it? 🤯🤷🏼♂️
Top of the lost, British Military use mills 6400 not degrees 360
Won't work as you go farther south...not on a spinning ball...