A multi-angle scan runs for hours, but every angle was referenced against
one background captured before the first row of the first angle. That
reference has drifted by the last angle, and comparing angles — the whole
point of a multi-angle scan — was comparing each one against a noise floor
measured at whichever angle came first.
Every angle now captures its own. Before each angle's rows, the operator is
prompted to switch the Genesis laser off, the engine averages a fresh CH1
record, and the operator switches it back on. The data block therefore reads
[background][scan][background][scan] …, one pair per angle.
Format v7 (scan) and v11 (SAW check) carry the background inside the data
block, one length-prefixed block ahead of each angle's rows; the single
block that sat between the preambles and the data is gone. Per-angle offsets
now come from a walk of the data block at parse time rather than arithmetic
over the geometry table, and an angle whose background is not fully on disk
is the frontier — nothing of it was written yet.
v6/v10 files still read: SrasFile hands their one background to every angle,
so readers never branch on the version. Nothing writes them, and a resume
refuses them, since a re-acquired angle writes a block the old layout has no
room for. A resumed v7 angle rewrites its background in place, and the
engine checks the new block fits the room the file has before writing it —
anything else would shift every row behind it.
Two fixes made along the way:
* QtScanController never accepted file_version, so every scan launched
from the app raised TypeError at construction.
* angle_status() left its cursor parked at the frontier, so every angle
past it reported the frontier's own data_offset — which handed a resumed
scan the same write position for several angles. Two recorded offsets in
tests/golden/sras_expected.json are corrected accordingly.
The v6 goldens stay as parser fixtures; the writer is now locked against
bytes the test lays out from scan_format.md itself.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A mis-triggered row cannot be written as it arrived — v6 declares n_frames per
row in the header and has no per-row length field, so a short or long row
would shift every later row in the file. Until now the only policy was to
square it up, which keeps the scan running but leaves the affected row
indistinguishable from a good one afterwards: nothing in the file records that
it was padded.
strict_rows selects the other trade. On any frame-count mismatch the scan
stops instead of writing the row, so a data run either produces rows that mean
what the header says they mean or fails loudly. Default stays pad, so existing
behaviour is unchanged.
_warn_frame_delta becomes _check_frame_delta, since it now decides rather than
just reports. Both acquisition paths already call it before writing anything
for the row (CH1 leads SCAN_CHANNELS, and the burst path checks every row up
front), so an abort leaves the file on a whole-row boundary rather than a
half-written row — test_strict_row_packing_writes_nothing_for_the_failed_row
pins that.
Plumbed through QtScanController to a checkbox in the scan panel, persisted in
ScanDefaults alongside burst_mode. scan_format.md documents both policies and
notes that the choice is not recorded in the file.
The row-clipping setup in the padding test is now a _clip_one_row helper,
reused by the strict tests. 92 tests passing, ruff clean.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Wires the burst_mode flag through QtScanController to ScanEngine and adds a
checkbox to the scan panel. The setting persists via ScanDefaults like the
other scan fields, defaulting to off — per-row acquisition stays the default
path until burst mode has run on the rig and the gate-off preflight has
settled which TRIGOUT value idles the pin low.
scan_format.md — the acquisition settings table had drifted from the code it
claimed to describe: it attributed the settings to sc3_aui_app.py (they moved
to core/scope_sras.py in the Phase 2 extraction), listed a 1.24 V trigger
level and 0 % offset where the code sets 0.500 V and HORizontal:POSition 30,
and did not mention the logic-AND scan trigger at all. Corrected, pointed at
the module that actually owns them, and noted that none of it affects byte
layout — only where the acoustic packet lands inside a frame.
Added an acquisition-paths section: the two paths write byte-identical files
and the choice is a runtime flag that is not recorded in the file, so a
reader never needs to care which produced it. Documents where row boundaries
come from in a burst and that either path squares rows up to n_frames.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The headline of the refactor. Scan orchestration no longer lives inside a
QObject that reaches through Qt workers for its hardware handles.
core/scan_engine.py — ScanEngine(stage, scope, rotator, plan, out_path,
resume, callbacks). Takes the concrete drivers, blocks in run(), reports
via plain callables, and prompts through an injected blocking callable.
No Qt import anywhere in the path (test_engine_imports_without_qt proves
it), so a simpler GUI or a CLI can drive the identical acquisition.
Supporting extractions, all Qt-free:
- core/scope_sras.py — SCPI policy: channel profiles, trigger programming,
background average, per-row FastFrame transfer
- core/rotation.py — RotationAxis + RotationSettings (the GR_* constants)
- core/scan_resume.py — frontier contiguity rule + settings compatibility
- gui/scan_bridge.py — QtScanController, exposing exactly the signal
surface the old ScanWorker had, so MainWindow's connections are unchanged
hardware/t3r_driver.py is now Qt-free: a plain Signal class, a threading
reader, and a polling thread instead of QObject/QThread/QTimer.
gui/qt_t3r.py re-emits its callbacks as queued Qt signals for the panels.
Fixes carried by the extraction:
- rotation waits on the driver's MOTION_DONE event instead of
time.sleep(estimate + 0.5)
- abort during an operator prompt now takes effect; the old
_prompt_event.wait() had no timeout and could not be interrupted
- the poll timer is a thread, so an I/O error tearing down the driver no
longer calls QTimer.stop() from the wrong thread
- T3RDriver.disconnect() renamed close(); it shadowed QObject.disconnect()
- per-frame DC means use np.frombuffer over the joined block instead of
struct.unpack per frame (~16k tuple allocations per row)
tests/fakes.py + test_scan_engine.py (14 tests) assert the exact command
sequence, file layout, resume seeking, abort/pause, and geometry
rejection before any hardware call; test_scan_resume.py covers the
frontier rule. 58 passing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Thomas Ales