csi_envelope — INTERFEROMETRY `envelope` op

• データ種: sweep → signal

• 呼び出し: import interferometry; interferometry.csi_envelope(signal, remove_bias=True) (または opsinterferometry.get("csi_envelope"))

Coherence envelope of a z-scan interferogram (analytic-signal magnitude).

`dsp.envelope computes |hilbert(x)|` for any 1-D signal and is called

here verbatim, so the two can never drift apart. The one thing added is the

one thing an interferogram needs and a generic signal does not: **removal of

the intensity pedestal**. An interferogram is `a + b*V(z)*cos(...)` with

`a > 0, and the analytic-signal magnitude of that is not b*V` — the DC

term passes through the Hilbert transform untouched and dominates.

Measured on the module's reference scan (`a = 0.5, b = 0.4`, envelope

sigma 1.2 um, surface centred): with the bias removed the envelope matches the

analytic `b*V(z)` to 1.83e-07; without it, the error is 0.5 — the

entire pedestal — and the recovered "envelope" never goes near zero.

`dsp.envelope` called directly on the same raw interferogram gives that

identical 0.5, which is the honest statement of what this operator adds. That

is why `remove_bias defaults to True; False` is available for a scan

whose pedestal you have already removed some other way, and it is your

statement that you did.

signal: 1-D scan intensities (`(n,)`, n >= 3).

remove_bias: subtract the scan mean before the transform.

Returns a 1-D float64 envelope of the same length.

Raises `ValueError`: a non-1-D, empty, too-short (< 3), non-finite,

complex or masked *signal*, a *signal* over :data:MAX_SCAN_POINTS elements

(checked before the float64 promotion), or a non-bool *remove_bias*.

• サンプルデータカタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。

• coherence_scanning — py -3.11 examples/coherence_scanning.py

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*Provenance: interferometry.py — INTERFEROMETRY operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

csi_envelope — INTERFEROMETRY envelope op