Analytical Method of Ballistic Error Propagation in Free Segment Under Earth's Non-spherical Perturbation

Abstract

The invention provides an analyzing method of free phase ballistic error propagation under nonspherical perturbation effect of the earth. For a typical ballistic missile, firstly, under a condition of considering the nonspherical perturbation effect of the earth, a high precisely simplified model applicable to free phase motion analysis and calculation is built; then according to small error assumption and linear system theories, an equiangular / equal geocentric distance / isochronous propagation model and the state transition matrix analytical solution of the equiangular / equal geocentric distance / isochronous propagation model are exported; further through decoupling lengthways and lateral propagation models, lateral errors resulting from higher order terms are corrected based on a least square fitting method; and the balance between the speediness and the accuracy in calculating the free phase ballistic characteristic under nonspherical perturbation effect of the earth is realized. The method provided by the invention has the advantages of rapid calculation speed, wide application area and accurate correction model and satisfying demands for rapid mobile lunch and on-missile real time calculation.

Description

technical field [0001] The invention relates to the technical field of flight dynamics, in particular to an analysis method for ballistic error propagation in a free segment under the earth's non-spherical perturbation. Background technique [0002] The main factors causing the deviation of the ballistic missile landing point include the error of the guidance tool and the error of the guidance method. With the improvement of the hardware level of the inertial measurement system, part of the error of the guidance tool can be effectively corrected, so that the error of the guidance tool of the ballistic missile is gradually reduced, so that the influence of the error of the guidance method is becoming more and more prominent. Moreover, the non-spherical perturbation of the earth is what causes the error of the guidance method. main cause of error. For intercontinental ballistic missiles with a range of more than 10,000 kilometers, the influence of the oblate earth perturbatio...

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Problems solved by technology

[0003] Even in a few cases, the earth's non-spherical perturbation factor has been preliminarily compensated to partially reduce the hit accuracy deviation caused by the non-spherical perturbation factor, but due to the incomplete characterization theory of the earth's non-spherical Clearly, there are various defects in the compensation method (for example, the compensation order is very low, generally only the harmonic items are compensated, such as the first few items such as J2 / J4 / J6). above, rather than calculating the compensation amount in real time), resulting in a large deviation of the landing point caused by the compensated non-spherical perturbation factor

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