Abstract: A method can include, or a system can be configured to perform the steps of, receiving satellite signals, determining a monitor condition, determining a monitor performance, determining a residual error magnitude, fitting the residual error magnitude, and determining a positioning solution.

Abstract: A method for estimating a constrained zonotope enclosing a motion state of at least one mobile target, the method including: a) linearizing a nonlinear transition model at an element of a first zonotope (Zx(tk?1)), b) computing transition linearization errors at different elements of the first zonotope (Zx(tk?1)), c) computing a second zonotope that contains all linearization errors, d) propagating (102) the first zonotope so as to obtain an a priori zonotope ({circumflex over (Z)}x(tk)) enclosing the motion state at a second moment (tk) after the first moment (tk?1), wherein the a priori zonotope ({circumflex over (Z)}x(tk)) is a linear projection of a hypercube, the hypercube being subject to at least one linear constraint, e) updating (104) the a priori zonotope ({circumflex over (Z)}x(tk)) so as to obtain an a posteriori constrained zonotope (Z?x(tk)) enclosing the motion state at the second moment (tk).