glossary+of+navigation+terms

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=Glossary of navigations terms=

4 Ds
these are the things to consider/remember when planning/following a navigational leg
 * Distance
 * Direction
 * Duration
 * Description (this will include contours as well as features passed on the way and any collecting features)

aiming off
when walking to a point on a linear feature, if you were to miss that specific point when you reached the linear feature you wooul dnot know whether the point lay to your left or right  by aiming off - deliberately aiming to miss the point by following a bearing to one side - when you reach the linear feature you will know which way to turn to find the point: e.g. by follwing a bearing of 080 rather than 090, you will have to turn "right" (souoth) when you hit the linear feature

aspect of slope
is the direction of a slope - in practical terms if you released a ball the direction it would roll downhill. this is perpendicular to the contour lines, and can therefore be used if you have to relocate

attack point
if the desitination is a small/indistinct feature, it may be easier to head first to a larger, more easily found, feature that is faily close and then move from their to the destiniation the more obvious feature is called an attack point

back bearing
<span style="font-family: Georgia,serif;">if you leave your start point and accurately follow a bearing then if you turn and look back at your start point the beearing back to there will be the bearing your are following +/- 180 (e.g. if travelling north, the bearing of your start point will be south) <span style="font-family: Georgia,serif;">this bearing to where you have come from is a back bearing <span style="font-family: Georgia,serif;">rather than adding or subtracting 180, the easiest method is simply to align the south end of the magnetic needle with north on the compass housing (assuming that is set for the bearing you are following). <span style="font-family: Georgia,serif;">if you are following your bearing accurately the direction of travel arrow will now point to the place you started from

<span style="font-family: Verdana,Geneva,sans-serif;">backstop
<span style="font-family: Georgia,serif;">= catching feature

<span style="font-family: Verdana,Geneva,sans-serif;">bearing
<span style="font-family: Georgia,serif;">the angle between a line connecting two points (usually start and end point) and the line running north south <span style="font-family: Georgia,serif;">(the nature of the north south line will determine if the bearing is grid or magnetic)

<span style="font-family: Verdana,Geneva,sans-serif;">box bearing
<span style="font-family: Georgia,serif;">technique used to get around an obstacle, e.g. very boggy ground, when following a bearing and counting paces <span style="font-family: Georgia,serif;">once the decision has been made whether to pass to the right or to the left of the obstacle <span style="font-family: Georgia,serif;">1) a 90 degree turn is made just before the obstacle is reached and that bearing is followed until clear of the obstaacle (count how many paces this takes) <span style="font-family: Georgia,serif;">2) another 90 degree turn (the opposite direection to the initial turn) is made back onto the original bearing - again count paces, this time adding to those before the obstacle was reached, and continue on this bearing until clear of the obstacle <span style="font-family: Georgia,serif;">3) a third 90 degree turn is made (the same way as the second) and this bearing is followed for as many paces as were followed in step (1) <span style="font-family: Georgia,serif;">4) a final 90 degree turn is made (the same direction as the first one): this should now place you back on the bearing being followed before the boxing and pace counting can continue

<span style="font-family: Verdana,Geneva,sans-serif;">break of slope
<span style="font-family: Georgia,serif;">point at which two uniform slopes of different gradients meet <span style="font-family: Georgia,serif;">i.e. a steep slope and a less steep slope meet <span style="font-family: Georgia,serif;">contour lines will be equally spaced either side of this but the spacing will be different on the two sides

<span style="font-family: Verdana,Geneva,sans-serif;">cardinal points
<span style="font-family: Georgia,serif;">north, south, east and west

<span style="font-family: Verdana,Geneva,sans-serif;">catching feature
<span style="font-family: Georgia,serif;">a feature that lies beyond your objective - ideally running across your route <span style="font-family: Georgia,serif;">will indicate, if reached, that you have gone too far and missed the objective

<span style="font-family: Verdana,Geneva,sans-serif;">checking the quadrant
<span style="font-family: Georgia,serif;">when taking a bearing from a map there are two common errors <span style="font-family: Georgia,serif;">1) having the direction of travel arrow point from the destination to the start point <span style="font-family: Georgia,serif;">2) having compass housing rotated so north end of the oerienting lines are pointing south on the map <span style="font-family: Georgia,serif;">either of these on their own will generate a bearing that is wrong by 180 degrees <span style="font-family: Georgia,serif;">before measuring the bearing on the map check to see which quadrant it should be in: 0-90, 90-180, 180-270, 270-360 <span style="font-family: Georgia,serif;">if the bearing you measure is not in the quadrant you expected check your method carefully

<span style="font-family: Verdana,Geneva,sans-serif;">COLDER
<span style="font-family: Georgia,serif;">mnemonic for care of clothing
 * <span style="font-family: Georgia,serif;">keep Clean
 * <span style="font-family: Georgia,serif;">avoid Overheating
 * <span style="font-family: Georgia,serif;">wear clothes Loose and Layered
 * <span style="font-family: Georgia,serif;">keep Dry
 * <span style="font-family: Georgia,serif;">Examine for damage regularly
 * <span style="font-family: Georgia,serif;">Repair promptly when necessary

<span style="font-family: Verdana,Geneva,sans-serif;">collecting features
<span style="font-family: Georgia,serif;">= tick features

<span style="font-family: Verdana,Geneva,sans-serif;">compass housing
<span style="font-family: Georgia,serif;">the part of a baseplate compass that contains the magnetic needle or disc and which is rotated on the base plate <span style="font-family: Georgia,serif;">usually marked with degrees or mils around the edge and with parallel lines within the cirecle (orienting lines)

<span style="font-family: Verdana,Geneva,sans-serif;">concave slope
<span style="font-family: Georgia,serif;">one steeper at the top than at the bottom - contour lines are close at the top than the bottom

<span style="font-family: Verdana,Geneva,sans-serif;">contours
<span style="font-family: Georgia,serif;">imaginary lines joining points of equal elevation (altitude) relative - usually above - sea level

<span style="font-family: Verdana,Geneva,sans-serif;">convex slope
<span style="font-family: Georgia,serif;">one steeper at the bottom than at the top <span style="font-family: Georgia,serif;">contour lines are closer at the bottom <span style="font-family: Georgia,serif;">a dangerous slope - you may start to descend then realise it is too steep but be unable to stop (ice, wet grass) <span style="font-family: Georgia,serif;">always take extreme care if descending unless you can see all the way to the bottom of the slope

<span style="font-family: Verdana,Geneva,sans-serif;">direction of travel (DOT) arrow
<span style="font-family: Georgia,serif;">that part of a compass base plate that is used when taking or following a bearing - it is pointed to the feature of which the bearing is taken or to the feature to be aimed for when following a bearing

<span style="font-family: Verdana,Geneva,sans-serif;">fire triad
<span style="font-family: Georgia,serif;">three things needed for fire: heat, oxygen, fuel

<span style="font-family: Verdana,Geneva,sans-serif;">grid bearing
<span style="font-family: Georgia,serif;">a bearing taken in relation to grid (rather than magnetic) north

<span style="font-family: Verdana,Geneva,sans-serif;">grid north
<span style="font-family: Georgia,serif;">the direction marked as north on a map <span style="font-family: Georgia,serif;">differs, almost always, from true north and from magnetic north <span style="font-family: Georgia,serif;">(on orienteering maps the north-south grid lines are parallel with magnetic north so no correction is needed for the difference between grid north and magnetic north)

<span style="font-family: Verdana,Geneva,sans-serif;">grid reference
<span style="font-family: Georgia,serif;">system for describing the square in which something lies <span style="font-family: Georgia,serif;">differs from co-ordinates, which are the intersections of lines <span style="font-family: Georgia,serif;">the numbers in a gride reference give the south west corner of the square <span style="font-family: Georgia,serif;">the size of the square depends on how many figures are in the gride reference: e.g. in the British OS grid, a six figure GR gives a square with sides 100m

<span style="font-family: Verdana,Geneva,sans-serif;">handrail
<span style="font-family: Georgia,serif;">a linear feature (ie long and narrow, not necessarily straight) that is easy to find and to follow even in poor visibility <span style="font-family: Georgia,serif;">examples are tracks, roads, streams, ridges, power lines, rail tracks, edge of a forest/wooded area <span style="font-family: Georgia,serif;">following a hand rail may be faster than a more direct route because the navigation is easier - this is especiallyuseful in poor visibility <span style="font-family: Georgia,serif;">a handrail that is perpendicular to your route and beyond your objective can be used as a catching feature <span style="font-family: Georgia,serif;">two handrails, one to either side of your proposed route, can be used to funnel you <span style="font-family: Georgia,serif;">handrails can allow navigation by map alone and can be used to help set a map

<span style="font-family: Verdana,Geneva,sans-serif;">index contour
<span style="font-family: Georgia,serif;">a thicker contour line every 5th contour interval - e.g. if contour interval is 10m the index contours will be at 50m intervals

<span style="font-family: Verdana,Geneva,sans-serif;">latitude
<span style="font-family: Georgia,serif;">(imaginary) lines around the earth that are parallel to the equator (and therefore parallel with each other) <span style="font-family: Georgia,serif;">equator = 0 degrees, and the poles 90 degrees <span style="font-family: Georgia,serif;">1 minute of latitude = 1 natical mile <span style="font-family: Georgia,serif;">lines of different latitude are of different size

<span style="font-family: Verdana,Geneva,sans-serif;">longitude
<span style="font-family: Georgia,serif;">(imaginary) lines that all run between the two poles <span style="font-family: Georgia,serif;">0 degrees runs through Greenwich in London and the other lines are indicated by how many degrees east or west they are from there <span style="font-family: Georgia,serif;">all lines of longitude are the same length <span style="font-family: Georgia,serif;">as they converge towards the poles, lines of longitude are not parallel

<span style="font-family: Verdana,Geneva,sans-serif;">magnetic bearing
<span style="font-family: Georgia,serif;">bearing taken relative to magnetic north: i.e. using a compass

<span style="font-family: Verdana,Geneva,sans-serif;">magnetic declination
<span style="font-family: Georgia,serif;">the angle between true north and magnetic north <span style="font-family: Georgia,serif;">when walking the angle between grid north and true north is usually too small to be of significance, so declination is usually used as the difference between magnetic and grid north (ie the adjustment that has to be made between a bearing taken from the map and one taken using a compass <span style="font-family: Georgia,serif;">as well the the value, declination, to be useful, also needs a direction (east or west) - this is given in the marginalia of most maps

<span style="font-family: Verdana,Geneva,sans-serif;">magnetic inclination
<span style="font-family: Georgia,serif;">most easily thought of as the vertical (perpendicular to the earth's surface) part of the magnetic field <span style="font-family: Georgia,serif;">rather than spinning a magnetic needle it makes the north end dip down <span style="font-family: Georgia,serif;">as this vaires over the earth a compass made for one area will not work properly in some other areas <span style="font-family: Georgia,serif;">there are some "global compasses" that can be used in all parts of the earth

<span style="font-family: Verdana,Geneva,sans-serif;">magnetic north
<span style="font-family: Georgia,serif;">the direction the north end of a magnetic needle points to

<span style="font-family: Verdana,Geneva,sans-serif;">map
<span style="font-family: Georgia,serif;">2 dimenional representation (a "pciture") of features on the earth <span style="font-family: Georgia,serif;">traditionally paper, becoming electronic more often <span style="font-family: Georgia,serif;">(some electronic ones now offer "walk through" feature that increases the illusion of 3 dimensions

<span style="font-family: Verdana,Geneva,sans-serif;">mil
<span style="font-family: Georgia,serif;">an unit of measurement for an angle - usually used in the military <span style="font-family: Georgia,serif;">generally there are 6400 mil in one complete circle, though some countries differ from this <span style="font-family: Georgia,serif;">an angle of 1 mil is equivalent to 1m at a distance of 1000m

<span style="font-family: Verdana,Geneva,sans-serif;">Naismith's rule
<span style="font-family: Georgia,serif;">guide for estimating how long a walk will take (the mobile bit of it - does not take into account rest/meal stops) <span style="font-family: Georgia,serif;">5km/h horizontally <span style="font-family: Georgia,serif;">30 minutes for every 300m of ascent

<span style="font-family: Verdana,Geneva,sans-serif;">orienting lines
<span style="font-family: Georgia,serif;">parallel lines on the compass housing (on some makes red at one end, black at the other) <span style="font-family: Georgia,serif;">placed over/parellel grid lines on a map running north south in order to apply or take a bearing

<span style="font-family: Verdana,Geneva,sans-serif;">pacing
<span style="font-family: Georgia,serif;">measuring distance covered when walking by counting "double paces" i.e. the number of times one foot strikes the ground <span style="font-family: Georgia,serif;">to be accurate you need to know how many paces you take to cover each sort of terrain <span style="font-family: Georgia,serif;">on good, flat, terrain most people take about 60 double paces to cover 100m

<span style="font-family: Verdana,Geneva,sans-serif;">relocation
<span style="font-family: Georgia,serif;">the act of establishing your position when lost/"temporarily mislocated" <span style="font-family: Georgia,serif;">the first part of relocation is avoidance if possible - keep track of your position; "thumbing" <span style="font-family: Georgia,serif;">the next part, if you need to relocate, is to admit early that you are not sure of your position: if things are not right stop and have a look and a think

<span style="font-family: Verdana,Geneva,sans-serif;">romer
<span style="font-family: Georgia,serif;">a scale marked on transparent material (including the base plate of a compass) that divides a grid square into 10 (or more) <span style="font-family: Georgia,serif;">used to take and apply grid references <span style="font-family: Georgia,serif;">also used to measure distances

<span style="font-family: Verdana,Geneva,sans-serif;">resection
<span style="font-family: Georgia,serif;">a method of locating yourself that involve taking bearings of three features identified on the ground and on the map, applying back bearings on the map from each of those feaures and noting where those back bearings overlap (they usually form triangle rather than intersecting at a single point) <span style="font-family: Georgia,serif;">in practice if you can see three such features you can locate yourself fairly well without needing to use resection

<span style="color: #000000; font-family: Verdana,Geneva,sans-serif;">**scale**
<span style="color: #000000; font-family: Georgia,serif;"> the ratio between the distance measured on the map and the true distance on the ground <span style="color: #000000; font-family: Georgia,serif;">( or map size:"real size")

<span style="font-family: Verdana,Geneva,sans-serif;">setting a map
<span style="font-family: Georgia,serif;">holding the map so the orientation of its features matches those on the ground - either by looking at the features themselves or by using a compass

<span style="font-family: Verdana,Geneva,sans-serif;">Silva 123 system
<span style="font-family: Georgia,serif;">a system for taking a bearing to be travelled and applying it on the ground <span style="font-family: Georgia,serif;">1: place compass on map and align from start point to destination (ensuring direction of travle arrow points to the destination) <span style="font-family: Georgia,serif;">2: turn the compass housing until the orienting lines are parallel with north south grid lines (and that north ends point north on map) <span style="font-family: Georgia,serif;">3: take compass from map and turn the whole compass (NOT just the compass housing) until the red end of the needle points to north on the compass housing. <span style="font-family: Georgia,serif;"> assuming no magnectic declination the direction of travel arrow now indicates your bearing <span style="font-family: Georgia,serif;">if declination is significant this needs to be taken into account between steps 2 and 3

<span style="font-family: Verdana,Geneva,sans-serif;">soses
<span style="font-family: Georgia,serif;">mnemonic used to aid terrain association <span style="font-family: Georgia,serif;">shape, orientation, size, elevation, slope

<span style="color: #000000; font-family: Verdana,Geneva,sans-serif;">terrain association
<span style="color: #000000; font-family: Georgia,serif;">matching features on the ground (hills, valleys, ridges etc) with contours on the map <span style="color: #000000; font-family: Georgia,serif;">thumbing a map <span style="color: #000000; font-family: Georgia,serif;">keeping track of your position as you move and moving your thumb so it lies over your last position <span style="color: #000000; font-family: Georgia,serif;">you will be less like to get lost if you do this, but if you do get lost relocation will be easier

<span style="color: #000000; font-family: Verdana,Geneva,sans-serif;">tick features
<span style="color: #000000; font-family: Georgia,serif;">feaures you are expecting to pass on a navigational leg that are "ticked off" as you pass them to confirm you are folloiwng the correct route (or their absence alerts you to being off course). also known as collecting features.

<span style="color: #000000; font-family: Verdana,Geneva,sans-serif;">tinder
<span style="color: #000000; font-family: Georgia,serif;">something that will light from a spark

<span style="color: #000000; font-family: Verdana,Geneva,sans-serif;">topographic map
<span style="color: #000000; font-family: Georgia,serif;">is one that has information that allows the reader to gain a 3D understanding of the area - mainly in the form of conours <span style="color: #000000; font-family: Georgia,serif;">an A to Z road map is an example of a mpa that is not topographic.