llnl / llnl/mttime

Question about inverting blasting signals in meter-scale mining environment

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Description

Dear sir, I have been trying to invert moment tensors of blasting signals with the mttime package, but I run into some problems when fitting the observed and synthesized waveforms (only contain Z component).
Since distances between blasting sources and receivers is around 60 meters, the high-frequency portion of the blast signal is relatively large, as shown below.
a544cbd24b0e4d87fc931fd15c0aee5

The corner frequency reaches 161.9048 Hz, and it poses challenges for selecting parameters of the bandpass filter.
When the parameters are set [30Hz, 160Hz] to contain low and high frequency of blasting signals, the differences between observed and synthesized waveforms are too large.
e3a71551a2df5fdefd61a105c863db0
When the parameters are set [120Hz,160Hz] containing only high frequency, the obtained results do not correspond to the characteristics of the blast signals.
Therefore, I would like to ask how to determine the filtering parameters applicable to the blast signal.
In addition, I found that the beach ball pattern of luna in the mttime package is inconsistent with the beach ball pattern in obspy.
1712411712946
Thank you for considering my question. I am eagerly anticipating your response.
Best regards,
Zhongwei Pei

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Research direction

Start by reviewing the mttime inversion workflow described in the report, including the bandpass settings, Z-only waveforms, and the comparison with ObsPy beach-ball output. Reproduce the reported behavior if the example data and environment are available; done should mean identifying whether this is a package defect or documenting the appropriate filtering and plotting behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
data
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
18/100

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