The above gives the radiation pattern of a perfectly conducting mast over perfectly conducting ground. The actual strength of the received signal at any point on the ground is determined by two factors, the power radiated by the antenna in that direction and the path attenuation between the transmitting antenna and the receiver, which depends on ground conductivity. The design process of an actual radio mast usually involves doing a survey of soil conductivity, then using an antenna simulation computer program to calculate a map of signal strength produced by actual commercially available masts over the actual terrain. This is compared with the audience population distribution to find the best design.