Three one-dimensional (1D) optical transducers are known to be effective in determining the spatial coordinates of a target (marker) with higher speed and accuracy compared to the two-dimensional (2D) optical transducers system. But one disadvantage is that it can only position one marker at a time and couldn't solve the correspondence problem when two or more markers are lighted simultaneously, for which reason this tracking system necessitates a markers controlling system and is inconvenient in some applications. This paper proposes an approach to solve the correspondence problem by adding a fourth linear transducer to the current three ones. The geometric model of this system is presented and the constraint for correspondence is deduced. An analysis of the constraint degeneration is given and simulation experiments are conducted under both ideal and error conditions. Experiments show that this approach enables 1D transducers system to perform both active and passive tracking, and its high tracking accuracy is further improved.