This research proposes a robust combined deterministic stochastic subspace identification algorithm. Such combined subspace identification algorithm derives a state space model from input-output data. The method of deterministic-stochastic identification within subspaces focuses on identifying a state model that captures the temporal responses of the structure. In this framework, a discrete form represents the state model. The stabilization diagram plays a crucial role in determining the model order needed to effectively represent the structure’s dynamic behavior, along with its corresponding modal properties, through cluster analysis.