A traffic collision avoidance system (TCAS) based navigation system including a TCAS equipped with a directional antenna, the TCAS configured to generate a RF transmission pattern at a selected frequency, the transmission pattern including a plurality of directional beams, receive a plurality of RF signals reflected from the ground across a selected frequency band, the selected frequency band including the selected frequency, and measure frequency differences between one or more beams of the plurality of RF beams and one or more beams of the plurality of RF signals reflected from the ground, and a computing systems in communication with the TCAS, the computing system configured to calculate a ground speed of the aircraft utilizing the measured frequency differences, calculate a drift angle of the aircraft utilizing the measured plurality of frequency differences, receive a heading reference of the aircraft, and determine an aircraft navigation parameter of the aircraft.