watex.methods.em.ZC.remove_ss_emap#

ZC.remove_ss_emap(fltr='ama', out=False, smooth=True, drop_outliers=True, **kws)[source]#

Filter Z to remove the static schift using the EMAP moving average filters.

Three available filters:

  • ‘ama’: Adaptative moving average

  • ‘tma’: Trimming moving-average

  • ‘flma’: Fixed-length dipole moving average

Could export new Edi if the keyword argument export is set to True

Parameters:

  • fltr (str , default='ama') –

    Type of filter to apply. Default is Adaptative moving-average of Torres-verdin [1]. Can be [‘ama’|’tma’|’flma’]

    The AMA filter estimates static-corrected apparent resistivities at a single reference frequency by calculating a profile of average impedances along the length of the line. Sounding curves are then shifted so that they intersect the averaged profile.

  • out (bool , default =False,) – Output new filtered EDI. Otherwise return Z collections objects of corrected Tensors.

  • smooth (bool, default=False,) – Smooth the tensor data along the frequencies.

  • versionadded (..) –

  • drop_outliers (bool, default=True) – Suppress outliers in the data when smoothing data along the frequencies axis. Note that drop_outliers does not take effect if smooth is False.

  • versionadded – Polish the tensor data along the frequency axis remove noises and deal with the static shift effect when interferences noises are strong enough.

Returns:

Z – Return None by default (when export is set to False)

Return type:

list of watex.externals.z objects or None

References

[1]

Torres-Verdin and Bostick, 1992, Principles of spatial surface electric field filtering in magnetotellurics: electromagnetic array profiling(EMAP), Geophysics, v57, p603-622.https://doi.org/10.1190/1.2400625

See also

remove_static_shift

Remove static shift using the spatial filter median and write a new edifile.

Examples

>>> import watex
>>> from watex.methods import ZC
>>> edi_sample = watex.fetch_data ('edis', samples =17 , return_data =True )
>>> zo = ZC ().fit(edi_sample)
>>> zo.ediObjs_[0].Z.z[:, 0, 1][:7]
array([10002.46 +9747.34j , 11679.44 +8714.329j, 15896.45 +3186.737j,
       21763.01 -4539.405j, 28209.36 -8494.808j, 19538.68 -2400.844j,
        8908.448+5251.157j])
>>> zc = zo.remove_ss_emap()
>>> zc[0].z[:, 0, 1] [:7]
array([12120.08320804+6939.9874753j , 13030.91462606+6522.58481295j,
       15432.0206124 +4970.42806287j, 21899.60942244+3826.47476912j,
       29109.17100085+4537.17072741j, 19252.07839732+4108.71578943j,
        9473.20464326+4146.50327315j])