RESEARCH ON NEAR FIELD PASSIVE LOCALIZATION BASED ON PHASE MEASUREMENT TECHNOLOGY BY TWO TIMES FREQUENCY DIFFERENCE

摘要

A new method to near field passive localization based on phase shift measurement technology by frequency difference is presented in this paper. Near field passive localization accurately is a difficult problem all the while, especially for a special distance range (neither long nor short). In terms of physics ultrasonic localization technology cannot be used to near field passive localization because of its sharp attenuation, so electromagnetic wave is the sole choice. TDOA (Time Difference of Arrival) method is of no effect since time difference of arrival signal can not be measured accurately with conventional method on the condition of near field by reason of electromagnetic wave's velocity which is same as light velocity. It is also difficult for only using traditional DOA (Direction of Arrival) method to locate an object quickly and accurately under the same condition for the same reason. The method on phase measurement technology by two times frequency difference can solve the question perfectly. The principal interpretation, measurement result and error analysis of phase shift measurement technology by frequency difference is presented in this paper.