A method synchronizes signals from unsynchronized sensors spatially dispersed in an environment. Each sensor acquires an unsynchronized signal from the environment. An identical timing signal is received in each sensor. Frequencies of the timing signal are substantially disjoint of frequencies of the unsynchronized signals. The timing signal is combined with the unsynchronized signal in each sensor. The combined signals are received by a signal processor where the combined signals are separated to recover the unsynchronized signals and the timing signals. Then, the unsynchronized signals can be time-aligned according to the recovered timing signals to produce time-aligned signals.