Navigation

A to Z

a guide to some navigation terms
this is by no means a complete list

it is a guide
it will be added to as time permits

 

 

A to Z
of some navigation terms

 

A

Accuracy
 Always, always navigate to the best of your ability,
See the note at the foot of this page

Aiming off
 The technique of deliberately aiming to one side of a small feature when walking on bearing to hit a handrail that will take you to your feature. more on aiming off

Altimeter
An altimeter is essentially a barometer that is calibrated to give height read out. It's accuracy is subject to weather conditions but can be very good. It is important to recalibrate at regular interviews to ensure this continuing accuracy. more on altimeters

Attack point
 An easily identified feature close enough to your objective to enable you to home in on it with some degree of certainty. more on attack points

B

Back bearings
 used for two purposes
1)  to check if you are still walking on the correct bearing.
2) it can also be used to return along your original route. more on back bearings

Back Marker
Whilst walking in difficult conditions such as fog, mist, snow, or darkness, appoint a back marker. Tell the back marker to shout at once if you are moving to quick or get out of sight.

Bearing
A direction in which to travel usually obtained using a compass more on bearings

left
using a compass
to take a bearing
in poor visibility
in the Lake District

C

Cairn
 A cairn is a man made pile of stones that has been left for navigational purposes.  Often cairns have been built along a path to assist in following the path in bad weather.
Cairns are also used to mark summits at mountain tops and summits that do not have a trig point on.

Cartographers
 A cartographer is the person who makes maps, the surveying, and drawing of maps is all part of the skill of Cartography.

Catching feature
 An easily identifiable feature used whilst following navigation techniques such as hand rail or walking on a bearing so as to indicate your position and stop you walking to far. more on catching features

Cocked Hat
 see Resection (below)

Compass
a tool that is used to take bearings, establish direction, set a map, etc. more on compasses

Contour Lines
 lines on a map which join areas of equal height, most contour lines are usually drawn in brown more on contour lines

 

Contouring
The skill of walking along following ground of the same height, this takes practice and you have to be careful to avoid the temptation to loses height as you contour.

D

Declination
 An American term meaning the same as magnetic variation (see magnetic variation below)

Degrees
 A compass gives you a bearing that is usually (unless using a military compass) marked in degrees.  The 360 degrees in a circle, compass bearings are referenced by the number of degrees they are away from north, in a clockwise direction. more on  degrees

E

Explorer Maps
 A type of map produced by the Ordnance Survey more on explorer maps

F

G

Go To
A navigational technique associated and used in conjunction with a GPS receiver (see below) If you plot a position into a GPS and then ask the unit to "GO-TO" the position you will be given, direction and distance information.
 Warning - use extreme caution when using the goto feature of a GPS.
If used indiscriminately it could put you in serious trouble.  more on goto using a gps

G.P.S.
Global Positioning System is a navigation tool that tells you where you are using signals from satellites more on GPS

Grid Lines
the lines that make up the grid squares that maps are divided up into (see national grid below) more on grid lines

Grid North
Is the northerly direction of the North-South grid lines on a map. The Grid starts at Greenwich, and uses lines of Longitude and Latitude. It is then sub devised into smaller areas (as used by the national grid.) more on grid north

left
an approximation of
"the three north's"
in common use

Grid References
A system of using the national grid (see below) to give accurate locations.  a four figure grid reference is accurate to 1KM. and a six figure grid reference is accurate to a hundred meters more on grid references

H

Handrails
The easiest form of navigation is to find something that is going where you want to go and then follow it e.g. a path, a wall. more on hand rails

I

Index Contours
A thicker contour line drawn every five lines to make it easier to add the height difference between contour lines. index contour lines are often drawn at 50 metere intervals. more on index contours

J

K

L

Landranger Maps
A type of map produced by the Ordnance Survey more on landranger maps

Leap Frogging
This technique is often used for accuracy when following a bearing.
One person walks ahead whilst travelling on the required bearing. They then stop to allow you to catch up.
You repeat the process until you reach (or can see your destination) more information on navigating in poor visibility

Lost
When you don't know your current position !!!
more on lost (including what to do if you are lost)

M

Magnetic North
Is the North that the red end of the compass point is attracted to, that and is therefore used for direction finding. It is a magnetic field in the earth’s crust that can reliably used for navigation. As we can calculate exactly where this North is, we can also calculate the difference between this and Grid North thus allowing us to determine correct direction of travel. more on magnetic north

Magnetic Variation
is the difference between magnetic north and grid north, because of this difference, we use a "Magnetic variation" when working from one to the other. This variation is found in the margin information of the map, it varies according to how far East or West you are, and alters with time.
When transferring from map to the field this variation must be added, (and vice versa.) more on magnetic variation

Map
the basis of all navigation more on the map

Map Scale
the way in which a map is drawn more on map scale

Map Symbols
A type of notation used to signify features on a map more on map symbols

left
examples of map symbols

church with spire
public bridleway
and trig point

N

Naismith's Rule
 A formula used to work out how much time a navigational leg will take. It takes into account both distance and height gain. more on Naismith's rule

National Grid
 A system unique in Britain (as most countries use the latitude and Longitude system of establishing position). It is very easy and very accurate to use.
The country is divided into 100 km. main grid squares that are given letters,  these 100 KM. squares are then divided into 1 Km. grid squares that are used as the basis of grid references. more on national grid

O

Outdoor Leisure Maps
A type of map produced by the Ordnance Survey more on outdoor leisure maps

P

Pacing
"Pacing" can be used to accurately measure distance covered. By knowing how many paces (either single or double) you take per 100 Metres you can accurately measure distance travelled  more on pacing

Q

R

Resection
A technique to establish where you are when lost, or to find out how far along a long path you have walked. more on resection

Ridge
A long thin land feature, that can be several hundred meters wide down to a "knife edge".  It is often awarkward to navigate along a ridge especially in bad weather when there is potential danger from the drop on either side.

left
the ridge on Crib Goch,
Snowdonia

Route Card
A pre-planned route with details of the navigation distances. more on route cards

S

Summit
a top (often a mountain top) is the highest point on the ground.

T

Ticking off features
As you pass features, such as path junction, stream, fence, they should be ticked off mentally, this will help you remember where in a navigational leg you are. more on ticking off features

Triangulation
 see Resection (above)

Triangulation Point (often called Trig Point)
A trig point is a small pillar (often found on a summit or high ground) it is used for cartography and survey purposes but is often a useful indication as where the summit is.

left
the trig point on
Crib-Y-Ddysgl summit
3496 feet / 1065 meters

True North
Is the North that is the actual "real" North, it is the top of the North / South axis around which the earth rotates. It is the North pole. However it is not used in navigation as grid North is much easier to use. more on true north

U

V

Vertical interval
 The amount of height between the contour lines (often but not always ten meters) more on vertical interval

W

Waypoint
 A term used for a position that has been entered into the memory of a GPS (see above for GPS)

White Out
True white out conditions are rare, they involve nil visibility in snow. The ground, and sky all look the same and it's impossible to tell what is ground and what is not.  Navigation is obviously very hard and potentially dangerous.
Often people say they have a white out when in mist or fog and navigation becomes hard.

X

X
Is for accuracy
See below after this A to Z

 

Y

Z

 

 

Should I have added accuracy
to "A" above ?

Always navigate as accurately as possible
If you drew an X on your map how much land would it cover ?

If you used a 1:50,000 map

Assuming your "X" is 3 mm wide and 3 mm high - it would cover 150 x 150 meters of land.

150 meters in any direction would put you over the edge if your "X" was on the top of this crag.

If the width of the pen stroke of your "X" was 1/2 of 1 mm wide - the width of the pen stroke would be 25 meters on land.

The area at the top of this crag is more like 25 meters wide.
If you walked on a bearing that was 6 degrees different to what you thought it was for a distance of 52 meters

the error would be 52 meters
a long way in poor visibility

If you walked 52 meters in the wrong direction here it could be fatal