The points at right angles to the North and South points are the East and West points. Similarly, a line from the center to the South celestial pole will define the South point by its intersection with the limb. The North point will then be the point on the limb that is closest to the North celestial pole. Ī line (a great circle on the celestial sphere) from the center of the disk to the North celestial pole will intersect the edge of the body (the " limb") at the North point. In astronomy, the cardinal points of an astronomical body as seen in the sky are four points defined by the directions toward which the celestial poles lie relative to the center of the disk of the object in the sky. Topographic maps include elevation, typically via contour lines. This cardinal direction may not necessarily match the road's orientation at every given location (see Wrong-way concurrency).Ĭardinal directions or cardinal points may sometimes be extended to include elevation ( altitude, depth): north, south, east, west, up and down, or mathematically the six directions of the x-, y-, and z-axes in three-dimensional space. In Canada, New Zealand, and the United States, each direction of travel along a numbered highway is assigned a cardinal direction.
#CARDINAL DEFINITION PORTABLE#
Many portable GPS-based navigation computers today can be set to display maps either conventionally (N always up, E always right) or with the current instantaneous direction of travel, called the heading, always up (and whatever direction is +90° from that to the right). A few cartographers prefer south-up maps. Most maps in medieval Europe, for example, placed east (E) at the top. That being said, in cartography north does not have to be at the top. Additionally, in most languages this same cardinal-relative mapping is sometimes used in everyday usage when the speaker uses the cardinal directional term instead of the corresponding body relative directional term, even though a relative directional term already exists in that language.
#CARDINAL DEFINITION HOW TO#
In turn, maps provide a systematic means to record where places are, and cardinal directions are the foundation of a structure for telling someone how to find those places. With the cardinal points thus accurately defined by convention cartographers draw standard maps with north (N) at the top, and east (E) at the right. These eight directional names have been further compounded known as tertiary intercardinal directions, resulting in a total of 32 named points evenly spaced around the compass: north (N), north by east (NbE), north-northeast (NNE), northeast by north (NEbN), northeast (NE), northeast by east (NEbE), east-northeast (ENE), east by north (EbN), east (E), etc.
Northwest (NW), 315°, halfway between north and west, is the opposite of southeast.Southwest (SW), 225°, halfway between south and west, is the opposite of northeast.Southeast (SE), 135°, halfway between south and east, is the opposite of northwest.Northeast (NE), 45°, halfway between north and east, is the opposite of southwest.The intercardinal (intermediate, or, historically, ordinal ) directions are the four intermediate compass directions located halfway between each pair of cardinal directions. The four cardinal directions correspond to the following degrees of a compass: The directional names are routinely associated with the degrees of rotation in the unit circle, a necessary step for navigational calculations (derived from trigonometry) and for use with Global Positioning Satellite ( GPS) receivers. See also: Points of the compass § Compass points Degrees of rotation Arbitrary horizontal directions may be indicated by their azimuth angle value. Points between the cardinal directions form the points of the compass. These eight shortest points in the compass rose shown to the right are: The intermediate direction of every set of intercardinal and cardinal direction is called a secondary intercardinal direction. The ordinal directions (also called the intercardinal directions) are northeast (NE), southeast (SE), southwest (SW), and northwest (NW). Relative to north, the directions east, south, and west are at 90 degree intervals in the clockwise direction. The four cardinal directions, or cardinal points, are the four main compass directions: north, south, east, and west, commonly denoted by their initials N, S, E, and W respectively. A compass rose showing the four cardinal directions, the four intercardinal directions, and eight more divisions.
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