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ESA-VirES / MagneticModel

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Higher order spline interpolation of the spherical harmonic coefficients. #10

Open pacesm opened 6 years ago

pacesm commented 6 years ago

Some of the magnetic models (e.g.,CHAOS-6-Core) require higher order spline interpolation of the spherical harmonic coefficients.

The magnetic model uses always linear interpolation of the coefficients which leads to small deviation from the right model values.

pacesm commented 5 years ago

When compared with a reference implementation of the CHAOS-6-Core x7 model for randomly selected locations it is apparent that the linear interpolation causes deviation < ±0.04nT:

image

When using the 6th order piecewise polynomial interpolation (as defined in the SHC file) the deviation drops practically to zero:

image