In 1544 the angle which is the dip was discovered by the engineer Georg Hartmann. The value of it can be measured even more reliably with a special instrument typically called a dip circle. In practice, ordinary compass needles may be weighted against dip or may be unable to move freely in the correct plane. The dip angle is said to be in principle the angle which is made by the needle of a vertically held compass. And the value if negative indicates that it is pointing upward.

The positive values of inclination indicate that the earth's magnetic field is pointing downward into the Earth that too at the point of measurement. This angle generally varies at different points on the surface of the earth. The magnetic dip or the dip angle or the magnetic inclination is the angle made with the horizontal by the line of the earth's magnetic field. The anomalies provide the basis for inferences that are about probable subsurface structure and composition. When plotted on a magnetic map, it is known as an aeromagnetic map if the magnetometer was flown across the area. The latter generally reflects the difference which is between theoretical and observed magnetic intensities at points of measurement with a magnetometer. The remnant of the magnetization of rocks and local or the regional magnetic anomalies. Geomagnetics is that branch of geophysics concerned with all aspects of the magnetic field which is of earth’s that is including its origin, variation through time and manifestations in the form of magnetic poles. When the component that is horizontal and the vertical component of the earth’s magnetic field are equal the angle of dip is equal to 45°. The angle of dip is 0° when the needle of the dip rests horizontally while the angle of dip is 90° when the needle of dip rests vertically. When the magnetic field points towards upward direction then the angle of dip is said to be negative.

The angle of dip is said to be positive when the magnetic field points in the direction that is downwards. The angle of dip usually is said it varies from point to point by providing the information which is related to the movement of the earth’s magnetic field. The angle of dip is also sometimes called the magnetic dip and is defined as the angle which is made by the earth’s magnetic field lines with the horizontal.

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