An investigation was made to examine the interference to a satellite sensor by varying the density of emitters on the surface of the earth within regions comparable in size to cities. Transmitters were regularly spaced within city “rectangles” and software was used to simulate the scan of a passive satellite sensor through the rectangle. The Effective Isotropic Radiated Power (EIRP) applied to each transmitter was adjusted iteratively to the point where the maximum interference value recorded was exactly the same as the interference threshold of the sensor. Results from these studies will be presented.