Research on Hybrid DOA and FDOA Passive Localization Using Dual/Multiple Aircrafts

The precise localization of the fixed emitters is one of the important tasks of the airborne passive location system.The hybrid direction of arrival(DOA) and frequency difference of arrival(FDOA) passive location using dual or multiple aircrafts is a new approach to realize the precise localization of the fixed emitters.Aiming at this kind of new location system,an effective and computationally efficient estimation method is proposed under the condition of single observation.The method firstly coarsely estimates the emitter' s position based on the azimuth angles and pitching angles using the pseudolinear transformation.And then taking the coarse estimate of the emitter' s position as the initial value,the Gauss-Newton iterative process is established to obtain the finer estimate of the emitter' s position jointly utilizing the FDOA,azimuth angles and pitching angles regarding the emitter.Based on the localization results of multiple observations,the weighted least square batch method and the weighted least square serial method are introduced to fuse these localization results according to different real time requirements.Finally,the simulation results validate the effectiveness of the localization method for single observation and fusion method for multiple observations.The estimated accuracy of the emitter's position approaches the Cramer Rao Lower Bound(CRLB) for Gaussian measurement error at the moderate error level.