Tensor Decompositions for Online Grid-Based Terrain-Aided Navigation
J. Matoušek, J. Krejčí, J. Duník, R. Zanetti
TL;DR
This work presents a CPD-based grid filter for high-dimensional state estimation where dynamics are invertible and measurements are highly nonlinear. By encoding the state density as a CPD and performing both measurement and time updates in CPD form, the method achieves real-time performance even in 4D TAN-like problems, thanks to block-diagonal dynamics and sparsely coupled measurements. Key contributions include a Hadamard product in CPD, Lagrangian advection-diffusion updates, and rank-management via cp_als, enabling scalability beyond traditional grid-based filters. Empirical results on terrain-aided navigation show competitive accuracy with significantly reduced computation time, while outlining future work to relax diagonal noise assumptions and extend to more general dynamics.
Abstract
This paper presents a practical and scalable grid-based state estimation method for high-dimensional models with invertible linear dynamics and with highly non-linear measurements, such as the nearly constant velocity model with measurements of e.g. altitude, bearing, and/or range. Unlike previous tensor decomposition-based approaches, which have largely remained at the proof-of-concept stage, the proposed method delivers an efficient and practical solution by exploiting decomposable model structure-specifically, block-diagonal dynamics and sparsely coupled measurement dimensions. The algorithm integrates a Lagrangian formulation for the time update and leverages low-rank tensor decompositions to compactly represent and effectively propagate state densities. This enables real-time estimation for models with large state dimension, significantly extending the practical reach of grid-based filters beyond their traditional low-dimensional use. Although demonstrated in the context of terrain-aided navigation, the method is applicable to a wide range of models with decomposable structure. The computational complexity and estimation accuracy depend on the specific structure of the model. All experiments are fully reproducible, with source code provided alongside this paper (GitHub link: https://github.com/pesslovany/Matlab-LagrangianPMF).
