Tdoa Location Of The Key Technology Of Multi-satellite Study

Passive location of emitter source has been playing an important part in navigation, aviation and aerospace. As it has no needing of transmitting any electromagnetic wave, it has some characteristics such as broad locating area, better concealment, strong anti-jamming power and so on.The paper consists of three parts: The Time Difference of Arrival(TDOA)Location and Geometric Dilution of Precision(GDOP), algorithms of TDOA without earth constraint and algorithms with earth constraint. The main contents are as follows:a) The Time Difference of Arrival(TDOA)Location are discussed, first, the TDOA theory has been studied, Also, the elements and Geometric Dilution of Precision(GDOP) are discussed, Then, the mean square error(MSE) and the Cramer-Rao lower bound(CRLB) is referred. Each graph of GDOP is simulated with different station distribution.b) Next, some algorithms of TDOA without earth constraint have been discussed detailedly, such as Chan method, maximum likelihood method, Spherical-Intersection Method, Spherical-Interpolation Method, Least Squares Algorithm. Each graph of Mean Square Error (MSE) is simulated with different TDOA measurement error. From the simulation we can see the maximum likelihood method has higher precision.c) At last, algorithms with earth constraint have been researched, such as Ho algorithm, Chan method and maximum likelihood method, some comparison is made and the theory analysis and computer simulation are made, from which we can see the Chan algorithm and maximum likelihood method make the location more efficient.