1Phillips M L,Hall T A,Esmen N A,et al.Use of global positioning system technology to track subject' s location during environmental exposure sampling[J]. Journal of exposure analysis and environmental epidemio logy,2001,11(3):207-215.
2Sayed A H,Tarighat A,Khajehnouri N.Network- based wireless location:challenges faced in developing techniques for accurate wireless location information[J].Signal Processing Magazine,IEEE,2005,22(4):24-40.
3Munoz D,Lara F B,Vargas C,et aLPosition Iocadon techniaues and aoolicafions[M].Academic Press.2009.
