  Accurate node localization is vital for mobile ad hoc networks (MANETs).
Current methods like Time of Arrival (TOA) can estimate node positions using
imprecise baseplates and achieve the Cram\'er-Rao lower bound (CRLB) accuracy.
In multi-hop MANETs, some nodes lack direct links to base anchors, depending on
neighbor nodes as dynamic anchors for chain localization. However, the dynamic
nature of MANETs challenges TOA's robustness due to the availability and
accuracy of base anchors, coupled with ranging errors. To address the issue of
cascading positioning error divergence, we first derive the CRLB for any
primary node in MANETs as a metric to tackle localization error in cascading
scenarios. Second, we propose an advanced two-step TOA method based on CRLB
which is able to approximate target node's CRLB with only local neighbor
information. Finally, simulation results confirm the robustness of our
algorithm, achieving CRLB-level accuracy for small ranging errors and
maintaining precision for larger errors compared to existing TOA methods.
