Abstract: Computers PC of n stations, each equipped with a storage device to accommodate the data to be cross-correlated, are connected to a line concentrator or communications network that has a switching function. The data allocated to each computer can be divided into n or more partial data, and each partial data is assigned to perform the cross correlation operation to each computer. Furthermore, in PC's connected in such a manner that data can be transmitted via a line concentrator or communication network, mutually between 2 PC's connected each other, the step of transmiting partial data from the PC to the partner PC connected to the PC is repeated. Thereby, it is possible to effectively distribute data as an object of the cross correlation operation stored in multiple storage devices of PC's to each PC.