According to an embodiment, there is provided a system and method of collecting seismic data using a predetermined pattern of source activations that is intended to control the properties of the resulting seismic signal. One embodiment utilizes a seismic source array (or, more generally, any collection of controllable sources) to create a series of spaced apart in time source activations, with the spacing and number of such activations being used to shape the resulting signal. In one method of building sweeps, the guns are fired at an increasing rate (decreasing time separation) as time goes by. Other patterns may be generated by decreasing the firing rate as time goes by, or some combination of the foregoing. In an embodiment, the rate of the increase or decrease in the firing rate will change from pattern to pattern.