A polar chart is made up of a polar coordinate system and one or more polar series plotted against one scale that lies on both or either the upper or right radius of a circle. Data points coordinates are calculated in terms of a a segment(r) of the circle's radius and the angle(theta) formed by the data point position with the right radius. So, if a data point has coordinates (r,theta), the x coordinate(r) is calculated with respect to the scale range, whereas the y coordinate is determined by applying the theta value to a trigonometrical function that also takes into account the x value to find the vertical distance from the data point to the polar circle radius.

Among several types of applications, a polar chart can be used to determine the response amplitude of diverse types of microphones, as omni-directional and cardioid microphones, based on the direction they are able to capture sound waves. Below we can see the pick-up pattern of a cardioid microphone, showing that they have a better response to frontal sound sources than sounds from behind. A polar line series is used to draw the pattern.