Flight Path Angle Steering with Lambert Guidance Reference

In this paper a new guidance technique for ballistic missiles and launch vehicles is proposed. Generally the Lambert guidance is used to generate missile nominal (correlated) parameters through powered flight to put it in a ballistic flight path. Because of uncertainties and undesired factors, the nominal position and velocity obtained by Lambert technique need to be followed in actual flight. In this paper the Flight Path Angle Steering (FPS) procedure is used to accomplish the tracking of nominal parameters. The numerical simulations indicate that the integrated procedure is a costeffective and suitable scheme for guiding ballistic missiles and launch vehicles especially in design process. In spite of the simplifications made in FPS procedure, numerical simulations show that there is very little difference between the results obtained by FPS and the results obtained by Q-guidance method.