Sun Compass - Southern Hemisphere

[Pict]

The shadow and stick method is a wilderness navigation staple that everyone should know how it do. It allows you to orient yourself just using the sun and a shadow. Most manuals show this method for the Northern Hemisphere. Things are reversed here below the Equator so I figured I'd shoot a video of the process from another angle, so to speak.

Sun Compass Southern Hemisphere

Mac

 

[SMARTY]

I'm confused. Does the sun rise in the West in the Southern hemisphere????? If it still rises in the East then the shadow and stick method is the same.

 

[Daegurth]

it goes east-north-west, rather than east-south-west like it does in the northern hemisphere.

so basically it's exactly the same technique, you just have to remember it's a mirror image and compensate. of course, if you have an analogue watch, you don't need to bother with the stick and shadow method, just point the hour hand at the sun and 12 is north. (northern hemisphere, six is north)

 

[SMARTY]

As I understand it roughly mid day in the Northern hemisphers is due South and reversed for the Southern hemisphere. I find the sun and watch thing very inaccurate, its exact only on two days a year. Shadow stick method again is only rough, becomming more precise the longet you leave the time between markers.

 

[Bernie Garland]

If you stand with the sun directly behind you in the uk at 12 noon you will be facing north,if you get used to your watch it can be used as a compass by the time of day.

Bernie

 

[Daegurth]

it's always accurate at midday, and reasonable the rest of the time. probably about on a par with those cheap button compasses that come in PSKs. if you don't have a map it's not a huge amount of use anyway, unless you know the area well. if you do have a map, you can work it out from landmarks.

if you're in a situation when you don't have a compass, it seems unlikely that you're going to have time to stop for at least a few hours just to determine which way is north, so the stick method has never seemed all that helpful to me.

 

[Wayland]

Most manuals also neglect to mention that it should be done in the hours either side of high noon as well.

The Vikings used a portable device made like this called a bearing dial for traveling at sea

 

[Bernie Garland]

Most manuals also neglect to mention that it should be done in the hours either side of high noon as well.

The Vikings used a portable device made like this called a bearing dial for traveling at sea

Ive tried it at other hours of the day with a compass,and it does work.

Bernie

 

[Wayland]

It will give you a rough line that is better than a poke in the eye with a sharp stick, but if your life depends on accuracy, it's best to have all the facts.

 

[pothunter]

Ive been interested in this for a while, it was recently discussed in an earlier thread and my conclusion is that sun compasses are only accurate at midday for any other hour of the day you must know the azimuth of sunrise and sunset to compensate http://www.timeanddate.com/worldclock/astronomy.html?n=298&month=6&year=2008&obj=sun&afl=-1&day=1

21/06/08 sunrise 128 deg, sunset 232 deg
21/12/08 sunrise 49 deg, sunset 311 deg

without being able to compensate you will have bearing either side of the direction you are plotting, these variations are exaggerated further N-S you travel reversing at the equator. One day I will put some of this data into an excel spreadsheet and see what kind of wave it generates.

Even the most basic compass is better than no compass at all if it saves you walking in circles.

I think the Viking's compensated using star sightings, they did prove to be consistently very accurate over long distances.

Pothunter.

 

[Wayland]

The Viking bearing dial plotted a line for the whole day on a plate with a fixed gnomen.

By turning the plate until the gnomen shadow tip touched the line at any time of the day, the plate was then correctly oriented.

Observers have noted that the curve would become inaccurate over time due to the daily change of Solar Declination, but in practice as the curve becomes inaccurate for the day you are traveling, in the forenoon you will be sent sightly to one side of your course and in the afternoon to the other side of your course by the same degree, so the cumulative difference becomes negligible.

 

[Tadpole]

it's always accurate at midday, and reasonable the rest of the time. probably about on a par with those cheap button compasses that come in PSKs. if you don't have a map it's not a huge amount of use anyway, unless you know the area well. if you do have a map, you can work it out from landmarks.

if you're in a situation when you don't have a compass, it seems unlikely that you're going to have time to stop for at least a few hours just to determine which way is north, so the stick method has never seemed all that helpful to me.

The sun rises in the east and sets in the west only on two days of the year around the 21st Mar and the 21st Sep each year. In Britain in winter, roughly speaking, the sun will rise in the southeast and set in the southwest, in the summer it will rise in the northeast and set in the North West.
To make the system work accurately, you have to make sure that you mark through the shortest shadow, and not 12 o’clock by your watch, noon is literally the “middle of the day” and not fixed at 12 o’clock. It is useful to know when the sunrises and sunsets, this will tell you the day length, and Noon is the middle of that. Therefore, if the sun rises at 05:36 and sets 21:02 your day is 15 hours 26 minutes long, meaning noon happens at 13:19 hours
sunrise &Sunset

Where you are by grid ref, long/lat and OS map

 

[SMARTY]

Nice one Tadpole. The US SERE training schools did a lot of research into this some time ago, as it was believed by some, that sun and watch and shadow sticks gave 100% accuracy. This probably came about from survival manuals and books which did not tell the reader otherwise. I fully agree that survival navigation only needs to be rough enough and we should expect inaccuracy due to gaps in our knowledge or we find ourselves in unfamiliar terrain etc. What I would suggest is that we could offer techniques to help reduce these inaccuracies when using improvised methods. For exmple when using sun and watch keep your navigation legs short and move from feature to feature.

 

[Daegurth]

The sun rises in the east and sets in the west only on two days of the year around the 21st Mar and the 21st Sep each year. In Britain in winter, roughly speaking, the sun will rise in the southeast and set in the southwest, in the summer it will rise in the northeast and set in the North West.
To make the system work accurately, you have to make sure that you mark through the shortest shadow, and not 12 o’clock by your watch, noon is literally the “middle of the day” and not fixed at 12 o’clock. It is useful to know when the sunrises and sunsets, this will tell you the day length, and Noon is the middle of that. Therefore, if the sun rises at 05:36 and sets 21:02 your day is 15 hours 26 minutes long, meaning noon happens at 13:19 hours
sunrise &Sunset

Where you are by grid ref, long/lat and OS map

interesting! i would go out and test it now if it wasn't well after noon, and raining heavily.

the survival books never seem to add that little justification in, simply covering the method itself. thanks.

 

[Pict]

Thanks for watching.

In the Nothern Hemisphere the sun rises in the east, travels through the southern sky, and sets in the west (generally depending on time of the year). The shadows move in a clockwise direction. Here below the equator the sun also rises in the east but travels through the northern sky and sets in the west. The shadows, as you can see in the video, move counterclockwise.

When checking the results with a compass you have to take magnetic declination into account. Checking my results with Google Earth my X was just about dead on doing this experiment from one hour before, to one hour after solar noon.

I found a video on YT done by Ron Hood that shows the same technique (better of course) from the Northern Hemisphere presepctive. I saved it to my favorites on my YT channel so people can compare if they´re interested.

I grew up in North America and have a pretty good natural sense of direction. I think alot of that is connected to the sun and shadows and the way things move through the day. When I arrived in Brazil it seriously messed up my internal compass, everything was upside down, my north and south got switched. I live 12 km due north of the city and it is all I can do sometimes to look at the city and believe I'm facing south towards Rio De Janeiro. Mac

 

[Lush]

Thanks for producing this interesting thread guy's. This seems like an excellent technique, also because it's simple. I still have to try it yet. I am sure it works fine. With the shadow stick method it's OK if the sun, from time to time, hides behind clouds I guess.

This YouTube Clip shows a few variations of the shadow stick method (with audio). It starts with a sun compass technique though...

Pict wrote:"Thanks for watching..."
So when is the next episode then Mac?

 

[Pict]

I try to post something to my Youtube Channel every week but it depends on my work load. The more work I have to do the more I am tempted to procrastinate and do a video. Right now with our planned move back to the US for a year I am totally swamped and therefore should be releasing a feature length film any day now.

Actually my wife has told me in no uncertain terms that I MUST go to the bush for a few days next week and she isn't giving me the option. It is the only thing that keeps my head together with all the stuff I have to do. So my general plan is to head out into the Cerrado with a few friends, my little camera, and a sack full of AA batteries and shoot some more.

I have noticed that I get the most YT traffic from bird traps and machete videos so maybe I'll do more stuff like that. YouTube is neat in that it shows you where people in the world watch from. I get alot of traffic from you guys in the UK. I'm no Ray Mears though and don't aspire to be but it is alot of fun to shoot videos in a part of the world most people ignore entirely. Brazil is not all AMAZON jungle, if anything my area resembles South Africa, which it used to be connected to back in the day. Mac

 

[SMARTY]

Yahoo another survival navigation myth put to bed...thanks fellas

 

[Lush]

I try to post something to my Youtube Channel every week but it depends on my work load. The more work I have to do the more I am tempted to procrastinate and do a video. Right now with our planned move back to the US for a year I am totally swamped and therefore should be releasing a feature length film any day now.

Actually my wife has told me in no uncertain terms that I MUST go to the bush for a few days next week and she isn't giving me the option. It is the only thing that keeps my head together with all the stuff I have to do. So my general plan is to head out into the Cerrado with a few friends, my little camera, and a sack full of AA batteries and shoot some more.

I have noticed that I get the most YT traffic from bird traps and machete videos so maybe I'll do more stuff like that. YouTube is neat in that it shows you where people in the world watch from. I get alot of traffic from you guys in the UK. I'm no Ray Mears though and don't aspire to be but it is alot of fun to shoot videos in a part of the world most people ignore entirely. Brazil is not all AMAZON jungle, if anything my area resembles South Africa, which it used to be connected to back in the day. Mac

Oh how vaque of me, I initialy just made a joke because: "thanks for watching" sounded like TV". I didn't read and realize that you do make clips/video yourself! In particular about the subject of "sun compass". I will have a look then! Excuse me.
cheers,
Lush