Navigation Terminology

Corin

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WORK IN PROGRESS/UNDER CONSTRUCTION

Ok Folks, the question has been asked to provide more tutorials on Navigation and I for one have not done anything yet, been busy with the end of financial year. Still busy but lets make a start!

Lets get a navigation terminology dictionary going, I will throw in a few to get this started, but feel free to comment on this post with whatever you want to add. I will start with a list and some basic definitions but there will be a lot of work in getting this complete so feel free to jump in and help! Personally I would prefer definitions in your own words, I know we can just copy something off the web, but would prefer if we make this a BushcraftOz thing if possible.

Eventually I would like to make each of these headings links to threads of their own, so that when you click on it you go to a full description of each term, with examples and so on. Your thoughts and assistance will be appreciated, and I invite all moderators to jump in and add stuff as time allows.



Aiming Off
Aiming off is a technique employed when it is essential to find a specific point on a lineal feature (road, creek, ridgeline etc) normally when navigating off track, by aiming off to one side of the target you will know which way to travel to get to the target. If you do not aim off and arrive on one side of the target the target could be in either direction (pictorial explanation to follow)​

Angular Mil
See Mil​

Attack Points

Azimuth
Clockwise horizontal angle measured from a known reference point to a desire point e.g. the angle from either true or magnetic north to a desired point. Not to be confused with a bearing Note: an azimuth needs to be defined by the user so others know the reference point e.g. that tree is my azimuth.​

Back Bearing
Basically a bearing 180 deg from the bearing being followed. A back bearing confirms you are following the correct path by pointing back to your start point.​

Bearing: Grid

Bearing: Magnetic

Catching Feature

Contour Line

Datum

Dead Reckoning

Declination

Degrees: Decimal

Degrees: DMS (Degrees Minutes and Seconds)


DMS
(Degrees, Minutes, Seconds)​

Elevation

Fix (see also Resection)
Fixing ones position from known points, usually a minimum of THREE points​

GPS

GRADE
vertical rise over horizontal run (rise over run), most commonly expressed as a percentage, ratio or angle e.g. 10%, 1:33, 20 deg​

Grid

Grid reference

Handrail

Intersection
fixing an unknown position from known points​

Latitude
East to west horizontal lines - remember by relating it to the time zones: 'We will give you some LATITUDE if you are LATE'​

Longitude
north to south vertical lines - remember by: 'it's a LONG way to the top if you wanna rock & roll'​

Lost
geographically embarassed due continental drift AKA who put that mountain there?​

Magnetic Inclination
Vertical compass angle​

Map: Topographic

Marginal Information

Mil
Angular Mil...

Mil stands for the NATO modified version of the Miliradian which is a trigonometric method of dividing a circle.

When doing trigonometry you learn that a circle is made up of 6283.185 miliradians (milrad), to make the math of navigation easier NATO chose to make it 6400, which works out well because the mil (6400) is used to measure size and distance also.

1 mil = 1cm at 10m, 10cm at 100m, 100cm at 1000m.

So when working out your hold offs you can work out (approximately) the distance from your chosen objective at a given distance.

View attachment 5781

Just to allow a clear view of the difference, the above image shows a compass card marked in both units, the outer ring is in mils, while the inner ring is measured in degrees.

6400 mils = 360 degrees, being a more precise system of bearings

1 mil = 0.056 degrees
1 deg = 17.7777777778 mils

6400 = 360/0 N
1600 = 90 E
3200 = 180 S
4800 = 270 W​

Navigation Data Sheet

North: Grid

North: Magnetic

North: True

Orientate

RELIEF
Vertical and/or horizontal representation of land (terrain)​

Resection

Romer

Scale

Topography
 
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Templar

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May want to add Mil & Degree to the list also...

6400 mils = 360 degrees, being a more precise system of bearings

1 mil = 0.056 degrees
1 deg = 17.7777777778 mils

6400 = 360/0 N
1600 = 90 E
3200 = 180 S
4800 = 270 W
 

Corin

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May want to add Mil & Degree to the list also...

6400 mils = 360 degrees, being a more precise system of bearings

1 mil = 0.056 degrees
1 deg = 17.7777777778 mils

6400 = 360/0 N
1600 = 90 E
3200 = 180 S
4800 = 270 W
Definitely, though you can explain that one in detail as I have no first hand experience working with mils. What does Mils mean?
 

Templar

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Angular Mil...

Mil stands for the NATO modified version of the Miliradian which is a trigonometric method of dividing a circle.

When doing trigonometry you learn that a circle is made up of 6283.185 miliradians (milrad), to make the math of navigation easier NATO chose to make it 6400, which works out well because the mil (6400) is used to measure size and distance also.

1 mil = 1cm at 10m, 10cm at 100m, 100cm at 1000m.

So when working out your hold offs you can work out (approximately) the distance from your chosen objective at a given distance.

b2_1186.gif

Just to allow a clear view of the difference, the above image shows a compass card marked in both units, the outer ring is in mils, while the inner ring is measured in degrees.
 

auscraft

Henry Arthur Readford
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I know mils means milliradians not milimeters and it equates to 1metre at a distance of 1000m (1 KM) It is a military system
And the 6400 mils is not mathematically correct but that is what we use so do the british and US army, and I know other countries use 6000 or 6200 mils that I am aware of.
For eg if you know two objects at 1000m away are 15 mils apart the the distance between them will be 15m
 

auscraft

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I didn't study Maths in the army Just nav :)
But I believe it is 6283.18 increments in 360 degees and at 1000m 1 mils = 1m with 6400 increments
 
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Templar

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Hmmm... thats a little off... but yes if you want pure Trigonometry it is correct.

The mil formula of 1mil = 10mm @ 10m comes from the Artillery where 1 "Click" = the distance the gun will move for each graduation on the dial and correction of fall of shot, so a 1mm correction (1mil = 1mm @ 1m) will equal a movement of shot of 1m @ 1000m.
1 "Click" = 100m @ 10,000m (10km) or 1mil of angle. Through reduction tables it stays constant, hence why 1mil = 10mm @ 10m, etc.

This is where we get the term Klick meaning a Kilometre too by the way...

For navigation though we don't need to worry about it, just understand that a mil is a finer graduation of a circle than degrees.
Degrees works well if you like to measure the world in Imperial measurements, but mils works better for those who use metric measurements as it can be related directly to a unit of measurement on the ground.
 
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Walker

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From my dodgy Surveying days memory, how about:

DMS (Degrees, Minutes, Seconds)
Azimuth (clockwise horizontal angle measured from a known reference point to a desire point) e.g. the angle from either true or magnetic north to a desired point. Not to be confused with a bearing Note: an azimuth needs to be defined by the user so others know the reference point e.g. that tree is my azimuth.
Magnetic Inclination (vertical compass angle)
Dead Reckoning
Longitude (north to south vertical lines) - remember by: 'it's a LONG way to the top if you wanna rock & roll'
Latitude (east to west horizontal lines) - remember by relating it to the time zones: 'We will give you some LATITUDE if you are LATE'
Fix (see Resection) - fixing ones position from known points, usually a minimum of THREE points
Intersection (fixing an unknown position from known points)
 

Corin

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Thanks Walker, I have added yours.... I will flesh out some more when I get bacj from the meet... busy couple of days ahead of me!
 

Bartnmax

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Hmmm... thats a little off... but yes if you want pure Trigonometry it is correct.

The mil formula of 1mil = 10mm @ 10m comes from the Artillery where 1 "Click" = the distance the gun will move for each graduation on the dial and correction of fall of shot, so a 1mm correction (1mil = 1mm @ 1m) will equal a movement of shot of 1m @ 1000m.
1 "Click" = 1000m @ 10,000m (10km) or 1mil of angle. Through reduction tables it stays constant, hence why 1mil = 10mm @ 10m, etc.

This is where we get the term Klick meaning a Kilometre.

For navigation though we don't need to worry about it, just understand that a mil is a finer graduation of a circle than degrees.
Degrees works well if you like to measure the world in Imperial measurements, but mils works better for those who use metric measurements as it can be related directly to a unit of measurement on the ground.
Great info thanks Karl (& Corin, & Aus', etc).

Learning a heap here. I've studied civ' nav' quite a bit but never had any skoolin' with Military nav.
Just one question though Karl.

From above "so a 1mm correction (1mil = 1mm @ 1m) will equal a movement of shot of 1m @ 1000m.
1 "Click" = 1000m @ 10,000m (10km) or 1mil of angle."

If it's 1m @ 1000m would the calc' then not be 100m @ 10,000m (10km) rather than 1000?

Seems to me if art' are using 1 click to adjust at 10km range then 1000m could potentially put em a hellova long way off (1000m or 1km) when adjusting at that distance. I'm assuming it's a small error or is there something I'm missing?

Thanx mate.

Bill.
(Don't mean to sound like I'm nit-picking so sorry if it comes across that way, just trying to get it right. At least it does show I'm reading & thinking about it).
 
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Templar

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Yes you are right Bill... it's a typo...thanks for pointing it out... it has been fixed now. :non sono stato io:
 

Stewart Townsend

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I am only talking about heavy weapons using the C2 sight unit and not Arty (but I think the process is the same).
The C2 unit shows elevation and bearing in mils.
In effect it makes your weapon (mortar gpmg) into a grid "compass". To do that you use an aiming post and using a compass shoot a bearing over the sight unit to the aiming post. With some calculations you set a deflection on the sight unit and it becomes a "grid compass". So you can predict your direction of your fall of shot using the C2 sight unit and your aiming post. Elevation is different.

The WORM formula is WIDTH over RANGE in kms = mils. A displaced fire controller will see the fall of shot and using the worm formula will correct the fall of shot (it is an angle, between point A and B).

So it all about the 1 mil is 1 metre at 1000 metres.
 

Walker

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Just remembered some really basic ones:

RELIEF - vertical and/or horizontal representation of land (terrain)

GRADE - vertical rise over horizontal run (rise over run), most commonly expressed as a percentage, ratio or angle e.g. 10%, 1:33, 20 deg
 

Calkayne

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Attack Points
Used when the Line of Sight to your goal is blocked.
It is a point of Navigation with a direct Line of Sight with which you can then see your goal.

Contour Line
A line on the map which indicates the terrain height. The top of the numbers are in the direction of ascent.

Handrail
A linear or near linear physical reference point (Fence, Creek) which you can use to reach your goal with ease.

Navigation Data Sheet
A sheet of paper used to keep you on track and also to keep people at home informed of your planned route.

Sheets vary but often include: Waypoint, Grid Reference, Altitude, Point of interest amongst others.

Very usefull for beginner to intermediate and longer tours.

North: Grid
Map North

North: Magnetic
Compass North

North: True
If you drew a line direct to the Pole from your position this would be True North

Resection
A method of using 3 identifiable objects at 120° intervals with which you are able to pin point your position on the map.

A bearing is taken from each object and a line drawn to your approximate position. This is repeated three times. The result is a triangle in which you are located.


Hope that helps.
 
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