Dirk Rathjen was born, in Timmendorfer Strand, near Hamburg, Germany, on November 11, 1947. He received the diploma in physics and the Dr.rer.nat. degree from Hamburg University, Hamburg, Germany, in 1972 and 1978, respectively.From 1978 to 1980, he was an employee of ERNO Raumfahrttechnik GmbH, Bremen, Germany, in the Department of Sea Technology. Since 1981, he has been with Krupp Atlas Elektronik GmbH, Bremen, Germany, in the Research Department, His fields of work have been optics and signal processing. His present research interests are in the areas of beam forming and passive ranging, application of these to underwater acoustics, and signal processing with optical methods.