THIS PROJECT AIMS TO ADVANCE THE STATE-OF-THE-ART FOR LANDER NAVIGATION BY JOINING THE CONCEPTS OF CONSIDER FILTERING AND SQUARE-ROOT FILTERING IN CONJUNCTION WITH HIGH-FIDELITY SENSOR MODELING TECHNIQUES. THE RESULTING NAVIGATION FILTER WILL BE ONE THAT COMBINES THE ADVANTAGES OF THE CONSIDER FILTER WITH THOSE OF THE SQUARE-ROOT FILTER TO ENABLE A COMPUTATIONALLY FEASIBLE NUMERICALLY ROBUST METHOD FOR NAVIGATION. COMPARISONS OF THE DEVELOPED NAVIGATION FILTER TO ALTERNATIVE TECHNIQUES WILL BE CARRIED OUT ON PROTOTYPE NAVIGATION FILTERS FOR THE PROBLEM OF DETERMINING A BEST ESTIMATED STATE AND ITS ASSOCIATED UNCERTAINTY FOR A VEHICLE PERFORMING AUTONOMOUS LANDING. MODELING SIMULATION AND ANALYSIS RESULTS WILL BE THOROUGHLY DOCUMENTED IN ORDER TO INFORM BENCHMARKING AGAINST OTHER APPROACHES.