时差定位最优布站方法研究

Optimum sensor array for passive localization from time differences of arrival

针对时差定位,提出了以优化布站来提升定位精度的方法.该方法以克拉美罗下界的迹最小为定位精度衡量指标,通过对时差定位条件下克拉美罗下界的影响因素进行分析,发现接收站到目标的距离对克拉美罗下界没有影响,而接收站到目标的角度对克拉美罗下界有影响.随后,对克拉美罗下界迹的表达式进行了推导,并求得其最小值及取最小值的条件,得到结论:当接收站包围目标并呈等角布站时,对目标定位的克拉美罗下界取得最小值,此时布站最优.

In the TDOA system, the method for improving the source location accuracy by sensor arrangement is proposed. The trace of the CRLB of a source estimate is the criterion. By analyzing the factors of the CRLB, it is found that the CRLB does not depend on the range between sensor and source, but on the direction from sensor to source. The expression for the trace of the CRLB is derived. Then its minimum value and the condition for achieving the minimum value are obtained. It is shown that the uniform angular array is the optimum sensor array when the source is surrounded by sensors.