serversdownandClaude Opus 4.8
685a17d180
The Thor/Micromate (series-4) IDFW binary carries the sensor self-check in its
fixed-header region (before the waveform body), as up to four records tagged
01 0e 3c/3d/3e/3f — the SAME channel ids as series-3 (Tran/Vert/Long/MicL).
Unlike series-3's delta-coded trailing block, series-4 stores each trace as a
raw int16-BE array after an 18-byte record header (2-byte sample count at
offset +8). Three-channel (mic-disabled) units carry only 3c/3d/3e.
New micromate/sensor_check.py: decode_idf_sensor_check(raw) locates the record
chain (id-ordered marker run, so a stray body match can't chain) and reads each
trace's int16 samples → {Tran,Vert,Long[,MicL]: [counts]}, or {} when absent.
Reverse-engineered + validated against 4 UM oracle events (added as fixtures):
clean geophone ring-downs on all, mic pulse trains on the 4-channel units,
correctly no MicL on the two 3-channel units. Validated by shape + cross-event
consistency (no Thor report strip to exact-match, unlike series-3's BW reports).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YDXjZCr4RqT2U3QvMDhgzf
68 lines
2.9 KiB
Python
68 lines
2.9 KiB
Python
"""Series-4 (Thor / Micromate IDFW) sensor self-check waveform decode.
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Reverse-engineered 2026-09-15 against 4 UM (Thor) oracle events. The IDFW
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binary carries the sensor self-check in its fixed-header region (before the
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waveform body) as up to four records tagged ``01 0e 3c/3d/3e/3f`` — the SAME
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channel ids as series-3 (Tran/Vert/Long/MicL). Unlike series-3's delta-coded
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trailing block, series-4 stores each trace as a raw int16-BE array after an
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18-byte record header whose sample count is a 2-byte field at offset +8.
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Three-channel (mic-disabled) Thor units carry only 3c/3d/3e — no MicL record.
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Validated by shape (geophone ring-down / mic pulse train) and cross-event
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consistency, since there's no Thor Event-Report strip to exact-match against.
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"""
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from pathlib import Path
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import numpy as np
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from micromate.sensor_check import decode_idf_sensor_check
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FIXDIR = Path(__file__).parent / "fixtures" / "thor-idf-sc"
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EVENTS = sorted(p.name for p in FIXDIR.glob("*.IDFW"))
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def _decode(name):
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return decode_idf_sensor_check((FIXDIR / name).read_bytes())
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def test_geo_channels_present_and_ringdown_shaped():
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# Every IDFW event has the three geophone self-checks; each is a large
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# one-sided deflection (~15000 raw counts) that rings back — the geophone's
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# damped impulse response.
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for name in EVENTS:
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sc = _decode(name)
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for ch in ("Tran", "Vert", "Long"):
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assert ch in sc, f"{name} missing {ch}"
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tr = np.asarray(sc[ch], dtype=float)
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tr = tr - tr[:4].mean() # reference to the pre-trigger baseline
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assert 40 <= len(tr) <= 300, f"{name}:{ch} n={len(tr)}"
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assert tr.min() < -8000, f"{name}:{ch} min {tr.min()}"
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# deflects one way and rings back toward / past the baseline
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assert tr.max() < abs(tr.min()), f"{name}:{ch} not one-sided"
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def test_mic_present_only_on_four_channel_units():
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# UM11719 / UM12947 record a mic; UM13981 / UM20147 are 3-channel
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# (mic-disabled) units and carry no MicL self-check.
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got = {name: ("MicL" in _decode(name)) for name in EVENTS}
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assert any(got.values()), "expected at least one 4-channel unit"
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assert not all(got.values()), "expected at least one 3-channel unit"
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for name, has_mic in got.items():
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if has_mic:
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tr = np.asarray(_decode(name)["MicL"], dtype=float)
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tr = tr - tr[:4].mean()
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# mic self-check is a bipolar pulse train — swings both ways, wide range
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assert tr.max() > 5000 and tr.min() < -5000, f"{name} mic not bipolar"
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def test_channel_ids_and_order():
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# ids decode to the canonical channel names, geo always in Tran/Vert/Long order
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sc = _decode(EVENTS[0])
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assert [c for c in ("Tran", "Vert", "Long") if c in sc] == ["Tran", "Vert", "Long"]
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def test_returns_empty_on_non_idf_input():
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assert decode_idf_sensor_check(b"not an IDF file") == {}
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assert decode_idf_sensor_check(b"") == {}
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