一种基于双重等式约束的运动辐射源FDOA定位新方法OA

Passive localization of moving targets on Earth is an important issue in situation awareness.For narrow-band emitters,Frequency-Difference-of-Arrival(FDOA)based localization is one of the most effective positioning sys-tems.Therefore,this paper investigates the localization problem of a moving target on Earth using only FDOA mea-surements.First,two equality constraints are constructed for the moving target,and the Cramér-Rao Lower Bound(CRLB)for FDOA localization is deduced under these constraints,which can quantify the performance gain resulting from the velocity constraint.Subsequently,an optimization model for the joint estimation of the position vector and ve-locity vector is established based on the Maximum Likelihood Estimation(MLE)criterion,incorporating the two equal-ity constraints.Using the algebraic property of both the FDOA measurement model and the velocity vector's equality constraint,a novel localization method based on augmented Lagrangian function is proposed,which achieves sepa-rate estimation of the position vector and velocity vector.Specifically,the proposed method only requires iterative opti-mization of the target position vector,while the velocity vector can be obtained in a closed form,thus reducing the in-fluence of the initial values and the risk of local convergence.In addition,the iterative convergence,mathematical opti-mality,and asymptotically statistical efficiency of the new method are proven,and the ill-conditioning of the localization problem is analyzed.The influence of target altitude information error on localization accuracy is also mathematically analyzed using the constrained error perturbation theory.Finally,simulation results verify the superiority of the pro-posed localization method over other related localization methods,as well as the validity of the theoretical performance analysis.