A Multisensor Decision Fusion System for Terrain Safety Assessment

This paper describes an onboard automated hybrid reasoning system for terrain safety assessment using multiple heterogeneous sensors onboard a spacecraft. An innovative feature of this system is integration of multiple sensing modalities and different reasoning engines into a unified approach. Three different frameworks for representation of data uncertainty are considered: fuzzy set theory, Bayesian probability theory, and Dempster-Shafer belief theory. The hybrid reasoning system is composed of three subsystems, namely, multisensor fusion, multidecision fusion, and tier-based fusion selection, where each tier represents a range of spacecraft altitudes. Simulation results are presented to illustrate the multisensor decision fusion methodology described in this paper. The developed capabilities will enable future spacecraft to land safely in more challenging planetary regions with scientifically interesting terrain features.