radians_to_strain

function of dascore.transform.strain

source

radians_to_strain(
    patch: Patch ,
    gauge_length = None,
    wave_length: float = 1.5500000000000002e-06,
    stress_constant: float = 0.79,
    refractive_index: float = 1.445,
)

Convert data in radians to strain (rate).

This applies the simple formula found in Lindsey, Rademacher, and Ajo-Franklin (2020) to convert data whose units have a radians component to strain.

Parameters

Parameter	Description
gauge_length ($L_g$)	The gauge length in meters.
wave_length ($\lambda$)	The laser wavelength in m.
stress_constant ($\zeta$)	The stress constant.
refractive_index ($n$)	The refractive index of the cable.

Note

Equation 3 of Lindsey, Rademacher, and Ajo-Franklin (2020): $${ϵ}_{xx}(t,x_j)=\frac{\lambda }{4\pi n{L}_g\zeta }\mathrm{\Delta }\mathrm{\Phi }$$

References

Lindsey, Nathaniel J, Horst Rademacher, and Jonathan B Ajo-Franklin. 2020. “On the Broadband Instrument Response of Fiber-Optic DAS Arrays.” Journal of Geophysical Research: Solid Earth 125 (2): e2019JB018145.