An Iterative Approximation to the Mixed-Signal Processor

An iterative array processor for two simultaneously arriving signals is developed which gives estimates equal to the maximum likelihood estimates. Using this processor, the array is first beamed on one of the two events to produce a signal estimate which is then time-shifted and subtracted from each of the original traces. The difference traces are then beamed to produce a signal estimate for the second event. The estimate for the second event is now shifted and subtracted from the original traces, and the resulting difference traces are rebeamed on the first event. The process is repeated until differences in successive signal estimates for the desired event fall below a pre-determined threshold. In addition to its use in processing two simultaneously arriving signals, the processor can be of use for detection of secondary phases in the coda of an event.