The NASA search for evidence of technological civilizations in space: project HRMS

NASA began in 1989 a project to search for microwave radio evidence of technological civilizations in space. The project, designated HRMS for High Resolution Microwave Survey, is designed to search the 1 to 10 GHz microwave window for narrow band signals that could be positively identified as being transmitted by a civilization of extraterrestrial origin. The project will use existing ground-based radio observatories throughout the world for the task. Two complementary strategies will be applied in the conduct of the search: the Targeted Search and the Sky Survey. The Targeted Search will observe about 800 Sol-like stars using the largest and most sensitive antennas available while the Sky Survey will scan the entire celestial sphere by continuously moving the smaller, more flexible antennas of the NASA Deep Space Network. This paper will discuss the overall requirements and concepts of project HRMS, focusing on the Targeted Search.