Observability: range-only vs. bearings-only target motion analysis for a leg-by-leg observer's trajectory

The aim of so-called range-only target motion analysis (ROTMA) is to estimate the trajectory of a target by a single platform collecting range-only measurements.We focus on the observability analysis when the target is in constant-velocity (CV) motion. More precisely, the observability conditions are established when the observer's trajectory is composed of one or several legs. We establish a link between the Fisher information matrix (FIM) and the observability, after having proven the similarity of this matrix with the FIM encountered in bearings-only target motion analysis (BOTMA). We compare observability statuses in BOTMA and ROTMA in the paper.