Gravity field modeling method suitable for high-precision inertial navigation system

Abstract

The invention discloses a gravity field modeling method suitable for a high-precision inertial navigation system. The problems that according to a traditional inertial navigation system, due to ellipsoid approximation, a normal gravity model is deficient in precision, and a high-order gravity field spherical harmonic model is not suitable for the inertial navigation system are solved. By the utilization of a one-one mapping relation of a gnomonic projection, through the mode that high-precision grid gravity acceleration information obtained through calculation of the spherical harmonic model is mapped to a cubic plane, complex spherical surface model recurrence calculation is converted into two-dimensional plane interpolation calculation, an accurate gravity field model is rapidly calculated, and the method has the advantage of being suitable for real-time resolving of the high-precision inertial navigation system.

Description

technical field [0001] The present invention relates to a gravity model applicable to an inertial navigation device in a long-duration carrier, and in particular to a fast and accurate calculation method for a three-dimensional gravity vector in a high-precision inertial navigation system. Background technique [0002] As a kind of autonomous navigation equipment, inertial navigation system has been widely used in aerospace, aviation, navigation and ground carrier and other fields. With the continuous improvement of the accuracy of inertial devices (gyroscopes, accelerometers), the high-precision pure inertia long-endurance navigation capability has become the development direction of the new generation of inertial navigation systems. In particular, with the development of cold atom technology, the navigation position error caused by inertial devices can be reduced to the meter level per hour, which makes the system-level error the main factor restricting the improvement of ...

AI Technical Summary

Problems solved by technology

This makes the complexity relatively increased under the condition of ensuring the accuracy of the model, which is not conducive to the real-time solution of the inertial navigation system

Therefore, directly substituting the high-order gravity model for the traditional model cannot be applied to the inertial navigation system

[0011] 2. Calculation timeliness problem

However, the calculation speed of the spherical harmonic model has a quadratic relationship with the model order, that is, every time the model order increases by 10 times, the calculation amount will increase by 100 times, which cannot meet the requirements of the update frequency of the navigation computer.

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