Navigation from sensors in gnss-denied environments

An aircraft-based navigation system comprising:

• a ground mapping surveillance system configured to receive surveillance receive signals of an airfield environment;
• a data storage unit for storing one or more sets of reference airfield features, wherein one or more reference airfield features of the one or more sets of reference airfield features are associated with at least one airfield and comprising at least two reference feature elements;
• at least one surveillance processor operatively coupled to the ground mapping surveillance system, the at least one surveillance processor configured to:
• detect, based on the surveillance receive signals, a feature set comprising a spatial arrangement of at least two feature elements;
• and
• map the feature set to at least one identified airfield feature of the one or more sets of reference airfield features;
• and
• a navigation computing system configured to:
• determine an aircraft position relative to the at least two feature elements associated with the at least one identified airfield feature;
• and
• generate a flight path vector to the airfield feature.