envelope op• Datenarten: sweep → signal
• Aufruf: import interferometry; interferometry.csi_envelope(signal, remove_bias=True) (oder opsinterferometry.get("csi_envelope"))
Kohärenzhüllkurve eines z-Scan-Interferogramms (Betrag des analytischen Signals).
> Die ausführliche Beschreibung unten ist der Originaltext — Zusammenfassung und Überschriften sind übersetzt.
`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*.
• Leitfaden zur Familie coherence_scanning
• Katalog der Beispieldaten (Download-URLs / Lizenzen) — 2-D nutzt skimage.data (BSD/Public Domain) plus synthetische Bilder, 3-D nennt Download-URLs echter Datenquellen (Stanford, PDS, …).
• Herkunft und Literatur der Operatoren — die Quellen der Forschung/Verfahren, auf denen diese Operatorfamilie beruht.
• Der kanonische Algorithmus (Autor, Jahr) und seine Anwendungen stehen im Familienleitfaden oben.
• coherence_scanning — py -3.11 examples/coherence_scanning.py
signal als Eingabe)—
envelope)—
*Provenance: interferometry.py — INTERFEROMETRY Operator-Registry. Diese Notiz wird von tools/opdocs.py md erzeugt (nicht von Hand bearbeiten).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.