Ndiku, Morris, ZakayoWong, Kainam ThomasWu, Yue Ivan2022-02-082022-02-082020-05The Journal of the Acoustical Society of America 147, 3209 (2020); doi: 10.1121/10.0001138doi.org/10.1121/10.0001322http://repository.embuni.ac.ke/handle/embuni/3974abstractThe linear array’sone-dimensional spatial geometry is simple but suffices forunivariate direction finding, i.e., isadequate for the estimation of an incident source’s direction-of-arrival relative to the linear array axis. However, thisnominalone-dimensional ideality could be often physically compromised in the real world, as the constituentsensors may dislocatethree-dimensionally from their nominal positions. For example, a towed array is subject toocean-surface waves and to oceanic currents [Tichavsky and Wong (2004). IEEE Trans. Sign. Process.52(1),36–47]. This paper analyzes how a nominally linear array’sone-dimensional direction-finding accuracy would bedegraded by thethree-dimensional random dislocation of the constituent sensors. This analysis derives the hybridCram er-Rao bound (HCRB) of the arrival-angle estimate in a closed form expressed in terms of the sensors’ disloca-tion statistics. Surprisingly, the sensors’ dislocation could improve and not necessarily degrade the HCRB, depend-ing on the dislocation variances but also on the incident source’s arrival angle and the signal-to-noise power ratioenThree-dimensional dislocations in a uniform linear array's isotropic sensors-Direction finding's hybrid Cramér-Rao boundArticle