This attempt to detect strong gravitational waves was made possible by the availability of several years of high-quality seismic data from a global seismic array. The data from the IDA network provides long-term low-frequency measurements of the earth's oscillations. The data had been cleaned of the instrument problems and other noise for a project to examine slow and quiet earthquakes, leaving only the strong earthquake noise to be removed.
The possibility of having large objects (Jayawardhana,1992) that might produce detectable waves if present as small-period binary systems gave at least a small possibility of detection. While Boughn and Kuhn(1984) and Tuman(1982) have examined seismic data for excitation from gravitational waves, they concentrated on the earth's resonant frequencies. Large amplitude waves away from the resonant frequencies might not be recognizable, although Tuman found that the even harmonics show more excitation than the odd harmonics as would be expected if they were being stimulated (Tuman, 1982, page 129).
This project helped prepare the Stanford Exploration Project for processing 3-D datasets. While the imaging done was crude and many complicating factors were ignored, the data preparation and imaging still required a large amount of computation. The IDA data is similar in size to a small 3-D dataset, and processing these data did show some weaknesses in the SEP's data-handling capabilities. This project did show that analyzing large data volumes was practical.
If gravitational waves had been detected, the earth's response might have provided useful information about the deep interior of the earth, since the waves excite the earth uniformly. Most of the information now available about the deep interior is derived from near-surface earthquakes sources. Detection might also have provided interesting astronomical information.