Method and system of determining altitude of flying object
AssigneeNorthrop Grumman Corporation
InventorsKirk W. Hayward, Larry G. Stephenson
Life of this patent
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Abstract
A method of determining an altitude of a flying object. A Blanchard altitude of a flying object is computed. A non-Blanchard reference altitude and a trajectory of the flying object are measured and input to a Kalman filter. In the Kalman filter, the non-Blanchard reference altitude and the trajectory are processed to derive a radius of jet stream curvature. A gradient wind correction factor is then computed as a function of the radius of jet stream curvature. The Blanchard altitude is then corrected in response to the gradient wind correction factor.
Claims15
A method of determining an altitude of a flying object, comprising:
- computing a Blanchard altitude of the flying object;
- measuring a non-Blanchard reference altitude of the flying object;
- comparing the Blanchard altitude and the non-Blanchard reference altitude to obtain a correction factor of the Blanchard altitude;
- computing a radius of jet stream curvature as a function of the correction factor;
- computing a gradient wind correction factor as a function of the curvature radius and a trajectory of the flying object;
- and
- correcting the Blanchard altitude in response to the gradient wind factor.
An inertial navigation and data system of a gradient wind error model, comprising:
- a Blanchard altitude computing processor, operative to compute a Blanchard altitude of a flying object;
- a reference altitude measurement system, operative to obtain a non-Blanchard reference altitude of the flying object;
- an inertial measurement device, operative to measure a trajectory of the flying object;
- a Kalman filter, operative to compute a radius of jet stream curvature in response to the non-Blanchard reference altitude received from the reference altitude measurement system and the trajectory received from the inertial measurement device;
- and
- a correction processor, operative to compute a gradient wind correction factor as a function of the radius of jet stream curvature and the trajectory to correct the Blanchard altitude received from the Blanchard altitude.
Dependencies are inferred from the claim text.