ON THE EXACT-SOLUTIONS OF PSEUDORANGE EQUATIONS

Three formulations of exact solution algorithms to the system of determined pseudorange equations are derived. It is demonstrated that pseudorange equations are hyperbolic in nature and may have two solutions, even when the emitter configuration is nonsingular. Conditions for uniqueness and for the existence of multiple solutions are derived in terms of the Lorentz inner product. The bifurcation parameter for systems of pseudorange equations is also expressed in terms of the Lorentz functional. The solution is expressed as a product of the geometric dilution of precision (GDOP) matrix, representing the linear part of the solution, and a vector of nonlinear terms. Using this formulation, stability of solutions is discussed.