ABSTRACT
The basic information required to locate a source, in two or three dimensions, is the measure of the distance from a set of reference points whose locations are known. In distributed sensor arrays (DSAs), there are a few nodes known as anchor nodes where an omnidirectional sensor measures signal strength. In the lighthouse effect method, a rotating parallel beam of light illuminates stationary sensors. Roemer suggested a simple method to generate a parallel beam. When a source is simultaneously radiating an event with a very large speed difference, the difference in time of arrival (ToA) can be used to estimate the distance of the source from the receiver. ToA is a popular measure for distance estimationa. Estimation of the direction of arrival (DoA) of a signal may be obtained with the help of an array of sensors located at each anchor node. Instantaneous frequency is different from the conventional frequency defined as the inverse of the period of one oscillation.
