ENH: seed sensor measurement noise per instance

[thc1006]

Pull request type

• Code changes (bugfix, features)

Checklist

• Tests for the changes have been added
• Lint passes locally (ruff check and ruff format --check; pylint 10/10 on the touched files)
• Sensor unit + integration tests pass locally (50 passing); relying on CI for the full slow suite
• CHANGELOG.md updated

Current behavior

Sensor measurement noise is drawn from the process-global NumPy RNG (np.random.normal), so there's no way to seed it. Noisy-sensor runs aren't reproducible, and the noise is fragile under parallel or forked execution where workers share or reset the global RNG. This is #1042.

New behavior

Adds an optional seed argument to the sensors, threaded through Sensor, InertialSensor, ScalarSensor and the four concrete sensors. Each sensor builds its own numpy.random.Generator from np.random.default_rng(seed) and draws its white noise and random walk from that instead of np.random.

seed=None (the default) keeps the noise random but per-instance, so existing behavior is unchanged unless you pass a seed. With a seed, the noise is reproducible and independent of the global RNG state.

_reset is left alone on purpose (no re-seed): re-seeding on every reset would make each run in a repeated or Monte Carlo loop draw identical noise, which isn't the goal.

tests/unit/sensors/test_sensor_seeding.py covers same-seed reproducibility, decorrelation across seeds, independence from the global RNG (and not consuming it, which is the regression guard for the original bug), and the GnssReceiver path.

Breaking change

• No

With seed=None the output is identical to before; the argument is opt-in.

Additional information

I kept seed out of the docstrings and to_dict/from_dict to keep the change minimal and consistent with the existing style (a couple of the sensor __init__s don't document every parameter either). Can add either if you'd rather.

Closes #1042

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[MateusStano]

I kept seed out of the docstrings and to_dict/from_dict to keep the change minimal and consistent with the existing style (a couple of the sensor __init__s don't document every parameter either). Can add either if you'd rather.

Please do add it to the docstrings! If there are any parameters from __init__ missing in its docstrings than there is something wrong there!

Also add seed to to_dict and from_dict, please.

Otherwise this is a great PR!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.80%. Comparing base (7e37cb0) to head (7fb685c).
⚠️ Report is 9 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1052      +/-   ##
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+ Coverage    81.75%   81.80%   +0.04%     
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  Files          119      119              
  Lines        15192    15199       +7     
===========================================
+ Hits         12420    12433      +13     
+ Misses        2772     2766       -6     

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[thc1006]

Thanks, done. I added the seed docstring to every sensor __init__ (and while I was in Gyroscope I filled in the name entry that was missing there too), and threaded seed through to_dict/from_dict, including GnssReceiver's custom to_dict. from_dict reads it with data.get("seed") so dicts saved before this change still load, defaulting to None.

Also added tests: the seed round-trips through the JSON encoder for every sensor type, plus a case for the missing-key default. I went through the encoder rather than a bare from_dict(to_dict()) because the inertial sensors' vectorized noise fields come back as lists that way, which is how the library actually saves and loads them.

[Gui-FernandesBR]

LGTM

[thc1006]

Hi @MateusStano, a nudge on this one. I addressed both of your asks in 300e96e2: seed is now documented in every sensor __init__ (I also filled in the name entry that was missing from Gyroscope while I was there), and it's threaded through to_dict and from_dict, including GnssReceiver's custom to_dict. from_dict reads it with data.get("seed") so dicts saved before this change still load.

Gui approved afterward and rebased the branch onto develop today, so the change request from your first pass is the last thing holding it. Whenever you get a chance to take another look, I'd appreciate it.