Information Technology Journal1812-56381812-5646Asian Network for Scientific Information10.3923/itj.2011.1150.1160XuWang Zi-shuHe 62011106According to the TOAs (time of arrival) of periodic signal of constant-speed moving target, this study proposes the algorithms to estimate its range, velocity, velocity components and position coordinates in the three-sensor TDOA (time different of arrival) location system. The traditional three-sensor TDOA positioning system can locate two-dimensional target but the result may be ambiguity or no solution. The unique solutions of velocity components and position coordinates of two-dimensional target can be obtained by using the method of Target Motion Analysis (TMA). For the target moving at a constant speed in three-dimensional space, we can make the two-valued estimations of its velocity components and position coordinates. Because the height value of a target flying in real space cannot be negative, we can position the target by excluding the false position. In simulation analysis, we have carried out contrastive analysis of the various algorithms and their estimation accuracies. The simulation results verify the validity of the proposed algorithms.]]>Chan, Y. and K.C. Ho,19944219051915Yong-Guang, C., L. Chang-Jin and L. Xiu-He,20043214521455Fawcett, J.A.,19883611931199Fogel, E. and M. Gavish,198824305308Foy, W.H.,197612187194Hammel, S.E., P.T. Liu, E.J. Hilliard and K.F. Gong,198918171180Huang, Z. and J. Lu,200440323325Moon, J.R. and S.C. Nordone,200036176188Nardone, S.C. and V.J. Aidala,198117162166Nardone, S.C. and M.L. Graham,199722168178Tremois, O. and J.P. Le Cadre,19963210301046Iltis, R.A. and K.L. Anderson,199632108120Song, T.L.,19963214681472Chao-Mou, Y. and Y. Zhi-Qiang,2009232224Zhong-Kang, S., G. Fu-Cheng and H. Dao-Wang,2008