The compass rose is an instrument used for spatial orientation.
In its most common representation, the cardinal (north, south, east and west) and collateral points (northwest, northeast, southeast and southwest) are present. Subcollateral points (north-northeast, east-northeast, east-southeast, south-southeast, south-southwest, west-southwest, west-northeast and north-northwest) are also often presented.
The compass rose was created with the objective of analyzing the direction of the wind and devising strategies for navigation. Its initial relationship with the wind and its appearance, similar to petals, were responsible for giving it this name.
Later, it was used as an instrument for spatial location and cartography (construction and study of maps).
The circle formed by the compass rose is equivalent to the horizon, taking the person as the center and surrounded by cardinal, collateral and subcollateral points.
Cardinal points
The cardinal points are the main points of a compass rose. They represent the two axes of a Cartesian plane (x and y) referring to the north-south (y-axis) and east-west (x-axis) directions.
Cardinal points:
- North (N)
- East (E or L)
- South (S)
- West (W or W)
On the compass rose, they comprise a circle and the distance between the cardinal points is 90° angles. North, as the referential, corresponds to 0º; the east, at 90º; the south, at 180º; the west, at 270º.
If we use the body as a compass rose:
- When we point out the right arm for the sunrise (East);
- O nose will point to the North;
- O left arm to West;
- At back will turn to the South.
side points
Collateral points lie between cardinal points.
Collateral Points:
- NE: northeast - between north (N) and east (E);
- SE: southeast - between south (S) and east (E);
- SW: southwest - between south (S) and west (W);
- NW: northwest - between north (N) and west (W).
subcollateral points
Subcollateral points fulfill the function of increasing the precision of the compass rose. For this purpose, they are placed between cardinal and collateral points.
Subcollateral points:
- NNE: north-northeast - between the north (N) and the northeast (NE);
- ENE: east-northeast - between east (E) and northeast (NE);
- ESE: east-southeast - between east (E) and southeast (SE);
- SSE: south-southeast - between the south (S) and the southeast (SE);
- SSO: south-southwest - between south (S) and southwest (SO);
- OSO: west-southwest - between west (W) and southwest (SO);
- WNO: west-northwest - between west (W) and northwest (NW)
- NNO: north-northwest - between north (N) and northwest (NW).
In English, west is translated by west, it is common that in some compass roses the letter "O" is replaced by "W".
Guidance via compass and compass rose
The magnetic compass is an instrument used for geographic orientation, it was invented by the ancient Chinese and popularized by the Arabs, around the 13th century.
In it, there is a compass rose and a pointer, called a needle. This needle points the direction the compass is facing, and is guided by a magnet that indicates the Earth's magnetic north.
The compass allows the user to locate and establish routes precisely in relation to cardinal, collateral and subcollateral points.
The compass rose and the regional division of Brazil
The regional division of Brazil was drawn up by the Brazilian Institute of Geography and Statistics (IBGE), and resulted in five regions: North, Northeast, Midwest, Southeast and South. Its representation follows the orientation of the global poles.
According to this division, the following are represented:
- Two cardinal points (North and South regions);
- Two collateral points (Northeast and Southeast regions);
- The Midwest, in reference to the center of the country and the western cardinal point.
See too:
- Cardinal points
- Cardinal, collateral and subcollateral points
- Compass
- Geographical coordinates
