__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

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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