Compass Points. Cardinal Points Getting a Bearing A bearing is a measurement of direction between two points. Bearings are generally given in one of.

Compass Points

Cardinal Points

Getting a BearingA bearing is a measurement of direction between two points.  Bearings are generally given in one of two formats, an azimuth bearing or a quadrant bearing.  An azimuth bearing uses all 360° of a compass to indicate direction.  The compass is numbered clockwise from north (0° is north, 90° is east, etc.), so a bearing of 42° would be northeast, a bearing of 200° would be southeast, and so on.  For quadrant bearings the compass is divided into four sections, each containing 90°.  The two quadrants in northern half of the compass are numbered from 0° to 90° away from north (clockwise in the east, counterclockwise in the west).  In the southern half of the compass, the two quadrants are numbered away from south (counterclockwise in the east, clockwise in the west).  Quadrant bearings are given in the format N40°E (northeast), S26°W (southwest), etc.  Whenever you measure a quadrant bearing, it should always be recorded with north or south listed first, followed by the number of degrees away from north or south, and the direction (east or west) away from north or south.  In other words, you would never give a quadrant bearing as E40°N or W24°S. 

Quadrant and Azimuth Bearing

Azimuth Bearing

• Azimuth– Measurements begin at north with 0°, rotate

clockwise 90° to the east, then on to 180° due south, next to 270° to the west, and return to 360° at north. The 360° system of Azimuth is shown here.

Quadrant Bearing

• Quadrant Bearing

– Bearing divides the 360° compass Azimuth into four quadrants of 90° each, named northeast (NE), southeast (SE), southwest (SW), and northwest (NW). Angular rotation in each quadrant is measured from the vertical axis (the north-south compass axis). The table and illustration shown here summarize the concept of

Bearing and the direction of measurement for each quadrant.

Two North Poles

There are actually two north poles - the Geographic north pole which is the axis around which the earth spins, and the Magnetic north pole which is where compass needles point.

Why are there two different poles? Good question!The magnetic north and south poles are the ends of the magnetic field around the earth. The magnetic field is created by magnetic elements in the earth's fluid outer core and this molten rock does not align perfectly with the axis around which the earth spins.

There are actually many different sources of magnetic activity around and in the world. All those influencing factors combine to create the north and south attractions at each spot on the globe. The actual strength and direction of 'north' is slightly different everywhere, but it is generally towards the 'top' of the planet.

http://www.ngdc.noaa.gov/seg/geomag/jsp/Declination.jspUse this website to find declination

Magnetic Declination for Victorville:12° 48' E changing by 0° 5' W/year

Magnetic Declination

The difference between the north geographic pole and the north magnetic pole is called magnetic declination or usually just declination. Depending on where you are on the earth, the angle of declination will be different - from some locations, the geographic and magnetic poles are aligned so declination is minimal, but from other spots, the angle between the two poles is pretty big.

Measuring a bearing So, you’re in the field with your map at point A and want to get to point B…how do you accomplish this?  The first thing you need to do is determine the bearing from point A to point B.  There are two ways to go about this.  The easiest way is to carry a protractor with you when you’re in the field.  If you have a protractor with you, place it on the map so it is oriented parallel to a north-south gridline, with the center of the protractor on point A (or on a line drawn between points A and B).  Once you have done this, you can simply read the bearing you need to go off of the protractor. 

If you don’t happen to have a protractor with you, you can determine the bearing you need using your compass.  To do this, place your compass on the map so that the edge of your compass is oriented parallel to a north-south gridline and the center of your compass is on the line between points A and B.  Now rotate the map and compass together until the north arrow on the compass points to 0° on the graduated circle.  You can then approximate the bearing you need by estimating where the line between A and B crosses the graduated circle.