environment.sources.rolling_stock_noise

The noise a railway vehicle emits, measured by ISO 3095:2013.

ISO 3095 is the type test of rolling stock: how a train, a locomotive or a wagon is measured so that two units measured on two tracks can be compared. It has four tests and one condition that makes the constant-speed test comparable at all, the track.

Clause 5, standing still. Microphones 7,5 m from the track centreline and 1,2 m high stand opposite the middle of equal areas 3 m to 5 m long along both sides of every car, plus two at 30° on a 7,5 m half circle off each end of the unit, only off the ends with a cab for a trailer unit (5.5.1.1). The level $L_{p\mathrm{Aeq},T}^i$ of every position, over at least 20 s, is energy averaged weighted by the length $l_i$ each position stands for, $(\pi /2)\times 7,5$ m for the end positions (STATIONARY_END_POSITION_LENGTH_M):

(Formulae 1 and 2, stationary_unit_level; Formula 3 is the same over one car). The result is the mean of three such sets rounded to the nearest integer decibel (5.8.1, stationary_test).

Clause 6, at constant speed. The pass-by level $L_{p\mathrm{Aeq},T_p}$ is the A-weighted equivalent level over the pass-by time $T_p$ of the unit, from its front to its rear for a fixed formation (6.6.3, pass_by_measurement), at 7,5 m and 1,2 m, or 25 m and 3,5 m at 200 km/h and above. Three runs per speed and side give a mean rounded to the integer; the louder side is the result (6.7.1, rolling_stock_test). The test speeds are 80 km/h and the maximum speed, or the maximum alone up to 80 km/h (6.6.2, type_test_speeds). The 2005 edition also defined the transit exposure level, the energy of a whole train’s passage normalised to its pass-by time,

(ISO 3095:2005, 3.14, Formulae 8 and 10, transit_exposure_level). The 2013 edition dropped it; its Annex B.4 keeps the same form, with the pass-by time of half the unit, for a single trailer at the end of a train (Formula B.1).

Clauses 7 and 8, starting and braking. Starting is measured two ways: the maximum $L_{p\mathrm{AFmax}}$ at 7,5 m at a cross section 10 m ahead of the unit and at further positions along a long unit (acceleration_test_positions), or $L_{p\mathrm{Aeq},T}$ at 25 m over the passage of the unit. Braking from 30 km/h is measured by $L_{p\mathrm{AFmax}}$ opposite the first car at standstill. Each takes three runs per position, averages them, rounds to the integer and keeps the highest (7.5.4, 7.6.4, 8.7). Three runs are valid when they are no more than 3 dB apart (9.3).

6.2, the reference track. A constant-speed result is comparable only on a track whose rail roughness is below the limit of Figure 2 and whose decay rates are above the limits of Figure 3, both printed as numbers on the page (REFERENCE_TRACK_ROUGHNESS_LIMIT_DB, REFERENCE_TRACK_DECAY_LIMITS_DB_PER_M). The roughness is measured by EN 15610 (acoustic_roughness) and the decay rates by EN 15461 (track_decay); check_reference_track brings the two together with the curve radius and gradient of 6.2.2. A track whose roughness exceeds the limit in a few bands can still be accepted by Annex C when the exceedance changes the pass-by level by no more than 1 dB (check_small_roughness_deviations), and Annex E bounds how much two tracks’ roughness could change a pass-by level (roughness_comparability).

The rest. Annex A characterises impulsive noise by the fastest rise of $L_{p\mathrm{AF}}(t)$ (impulsiveness_rise_speed); 6.3.4 accepts a vehicle next to the unit under test when it adds no more than 2 dB (check_adjacent_vehicle_neutrality); Annex D.4.2 corrects for a steady background (background_level_increase); and Annex G sums an uncertainty budget whose example, Table G.2, is the numerical oracle of this module (pass_by_uncertainty).

Roundings. 5.8.1, 6.7.1, 7.5.4, 7.6.4 and 8.7 round to the nearest integer decibel and 6.3.4 to one decimal, without a rule for a value on the half; a half goes up here, a convention of this module, and so does a mean that binary arithmetic lands a hair under it (runs of 70,1 dB, 70,3 dB and 71,1 dB average to 70,5 dB and give 71 dB).

Read from ISO 3095:2013 (third edition) and, for the transit exposure level, BS EN ISO 3095:2005 (second edition).

Auto-generated from the source docstrings by scripts/generate_api_docs.py (make api-docs). Do not edit by hand.

acceleration_test_positions(unit_length_m: float) -> NDArray[np.float64]

Where the microphones of the maximum level starting test stand, 7.5.1.1.

One at the front cross section, 10 m ahead of the front of the unit. A unit longer than 50 m also has one 10 m ahead of its middle, and when those two are more than 50 m apart the gap is split into equal spacings of no more than 50 m (Figure 10: a 108 m unit has positions 10 m ahead of it and 17 m and 44 m behind its front).

Parameters

Returns: The positions, in metres behind the front of the unit at standstill, the front cross section first at -10 m; read-only.

Raises

AdjacentVehicleNeutrality(
    with_adjacent_level_db: float,
    unit_level_db: float,
)

Whether a vehicle next to the unit under test is acoustically neutral, 6.3.4.

Parameters

property

How much the adjacent vehicle adds, from the levels rounded to one decimal, in dB.

property

Whether the adjacent vehicle adds no more than 2,0 dB.

AdjacentVehicleNeutrality.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the two levels and the 2 dB the adjacent vehicle may add.

Parameters

Returns: The axes drawn on.

background_level_increase(
    measured_level_db: ArrayLike,
    background_level_db: ArrayLike,
) -> float | NDArray[np.float64]

How much a steady background raises a measured level, Formula D.1.

The informative procedure of Annex D.4.2 for sites that cannot meet the 10 dB margin of 5.2.3, 6.1.3, 7.2.3 and 8.1.3; it is used only when the level stands more than 3 dB above the background, and band by band for a spectrum.

Parameters

Returns: $\Delta L$, in dB, as one value or one per band.

Raises

check_adjacent_vehicle_neutrality(
    with_adjacent_level_db: float,
    unit_level_db: float,
) -> AdjacentVehicleNeutrality

Is the vehicle next to the unit under test acoustically neutral? 6.3.4.

It is when it is of the same class as the unit, or when the pass-by level over the units under test and the adjacent vehicle, $L_{p\mathrm{Aeq},T_{p1}}$, is no more than 2,0 dB above the level over the units alone, $L_{p\mathrm{Aeq},T_p}$, both rounded to one decimal for the comparison (Figure 5). This is the second test; it is made at least once for each tested speed.

Parameters

Returns: The verdict.

Raises

check_reference_track(
    roughness: Sequence[AcousticRoughnessSpectrum],
    decay_rates: Sequence[TrackDecayRate],
    *,
    speed_kmh: float,
    curve_radius_m: float | None = None,
    track_gradient_ratio: float | None = None,
    small_deviations: SmallRoughnessDeviation | None = None,
    roughness_limit_db: Mapping[float, float] = mappingproxy({0.4: 17.1, 0.315: 15.0, 0.25: 13.0, 0.2: 11.0, 0.16: 9.0, 0.125: 7.0, 0.1: 4.9, 0.08: 2.9, 0.063: 0.9, 0.05: -1.1, 0.04: -3.2, 0.0315: -5.0, 0.025: -5.6, 0.02: -6.2, 0.016: -6.8, 0.0125: -7.4, 0.01: -8.0, 0.008: -8.6, 0.0063: -9.2, 0.005: -9.8, 0.004: -10.4, 0.00315: -11.0}),
    decay_limits_db_per_m: Mapping[str, Mapping[float, float]] = mappingproxy({'vertical': mappingproxy({250.0: 2.0, 315.0: 2.0, 400.0: 6.0, 500.0: 6.0, 630.0: 6.0, 800.0: 2.19, 1000.0: 0.8, 1250.0: 0.8, 1600.0: 0.8, 2000.0: 0.8, 2500.0: 0.8, 3150.0: 0.8, 4000.0: 0.8, 5000.0: 0.8}), 'lateral': mappingproxy({250.0: 2.04, 315.0: 1.38, 400.0: 0.94, 500.0: 0.64, 630.0: 0.43, 800.0: 0.29, 1000.0: 0.2, 1250.0: 0.2, 1600.0: 0.32, 2000.0: 0.5, 2500.0: 0.5, 3150.0: 0.5, 4000.0: 0.5, 5000.0: 0.5})}),
) -> ReferenceTrackCheck

Is this track a reference track for a constant-speed type test? 6.2.

6.2.5. The roughness of every rail (every line, when 6.4.3 of EN 15610 asks for three) must cover at least 0,003 m to 0,10 m up to 190 km/h and 0,003 m to 0,25 m above, and must not exceed the limit of Figure 2 in any band (EN 15610 clause 8). A small exceedance is accepted when Annex C finds its effect on the pass-by level at most 1 dB: pass the result of check_small_roughness_deviations for the speed. A line analysed by the digital filters of EN 15610 Method B (filtered_roughness_spectrum) must also have at least 15 m of record analysed once 2 m are discarded at either end of each record (EN 15610 7.4.3), judged on the record length its average carries.

6.2.6. The vertical and the lateral decay rates of every set of measurements must be at least the limits of Figure 3 in every band from 250 Hz to 5 000 Hz (EN 15461 clause 8). When the rates come with their grid, clause 7 and 6.7 of EN 15461 are judged too: every rate at least twice the floor of Formula 2, and the farthest response 10 dB below the direct one.

6.2.2. When given, the curve radius must be at least minimum_curve_radius of the speed, and the gradient at most 5:1 000 (the gradient applies where powered units are tested).

Parameters

Returns: The verdict, with every requirement and its numbers.

Raises

check_small_roughness_deviations(
    roughness: AcousticRoughnessSpectrum,
    noise_levels_db: ArrayLike,
    *,
    frequencies_hz: ArrayLike,
    speed_kmh: float,
    limit_db: Mapping[float, float] = mappingproxy({0.4: 17.1, 0.315: 15.0, 0.25: 13.0, 0.2: 11.0, 0.16: 9.0, 0.125: 7.0, 0.1: 4.9, 0.08: 2.9, 0.063: 0.9, 0.05: -1.1, 0.04: -3.2, 0.0315: -5.0, 0.025: -5.6, 0.02: -6.2, 0.016: -6.8, 0.0125: -7.4, 0.01: -8.0, 0.008: -8.6, 0.0063: -9.2, 0.005: -9.8, 0.004: -10.4, 0.00315: -11.0}),
) -> SmallRoughnessDeviation

May a track whose roughness exceeds the limit still be used? Annex C.

Step 1 (C.2.1). The just-compliant spectrum is the measured one held down to the limit, $\min [L^{\mathrm{measured}}(\lambda ),L^{\mathrm{limit}}(\lambda )]$ (Formula C.1); where the limit sets no value the measured level stands.

Step 2 (C.2.2). Both spectra are carried from wavelength to frequency at the train speed, $f=v/\lambda$, and the energy of each band is shared among the normalised one-third octave bands in proportion to the width it covers (redistributed_band_energies, the Annex C algorithm of EN 15610 adapted to bands of unequal width). The correction is $\Delta L_{r,\mathrm{rail}}(f)=L^{\mathrm{measured}}(f)-L^{\mathrm{corrected}}(f)$ (Formula C.2), zero where no roughness band reaches.

Step 3 (C.2.3). The revised noise spectrum is the measured one less the correction (Formula C.3), and the effect is the energy sum of the measured spectrum less that of the revised one (Formula C.4). The track is compliant when that is at most 1 dB (C.3), judged for one pass-by at each speed.

Parameters

Returns: The verdict, the limit it was judged against and every intermediate spectrum.

Raises

impulsiveness_rise_speed(
    times_s: ArrayLike,
    levels_db: ArrayLike,
) -> RiseSpeedResult

The rise speed that characterises impulsive noise, Annex A.

The rising slopes of $L_{p\mathrm{AF}}(t)$ are the stretches where it increases from one sample to the next without a break; only those that rise by 10 dB or more count. Each gives its steepest rise

(Formula A.1), taken here as the largest difference quotient between neighbouring samples, and the result is the largest of them, $s=\max (s_j)$. The history should be sampled finely enough for the derivative to mean something; pass_by_measurement stores it every 10 ms.

Parameters

Returns: The slopes and their rise speeds.

Raises

minimum_curve_radius(speed_kmh: float) -> float

The smallest radius of curvature the test track may have, 6.2.2.

1 000 m for tests up to 70 km/h, 3 000 m above 70 km/h and up to 120 km/h, 5 000 m above 120 km/h.

Parameters

Returns: The minimum radius, in metres.

Raises

pass_by_measurement(
    signal: SignalInput,
    fs: float | None = None,
    *,
    start_s: float,
    end_s: float,
    pass_by_time_s: float | None = None,
    front_passing_s: float | None = None,
    rear_passing_s: float | None = None,
    history_interval_s: float = 0.01,
) -> PassByMeasurement

The pass-by quantities of one record, 6.5 and 6.6.3.

The record is A-weighted (IEC 61672-1) and the equivalent level

is taken over the measurement interval (3.14); it is the pass-by level $L_{p\mathrm{Aeq},T_p}$ when the interval is the unit’s pass-by time, from its front to its rear for a fixed formation, from the centre of the first unit under test to the centre of the last within a train (6.6.3). $L_{p\mathrm{AF}}(t)$ is the A-weighted level with time weighting F, whose integrator starts from the mean square of the first 125 ms so the record’s start does not read as an onset; its maximum within the interval is $L_{p\mathrm{AFmax}}$ (3.13). Given the pass-by time $T_p$, the result also carries the energy of the interval spread over it, the transit exposure level of ISO 3095:2005 (PassByMeasurement.normalized_level_db).

6.6.3 asks that the record start at least 10 dB below the level when the front of the train is opposite the microphone and end 10 dB below the level at its rear; the result keeps both margins.

Parameters

Returns: The levels of the record.

Raises

pass_by_time(unit_length_m: float, *, speed_kmh: float) -> float

The time $T_p=l/v$ a unit takes to pass a point, in seconds.

ISO 3095:2005 3.14 defines it for a whole train as its overall length divided by its speed. For the single trailer unit of Annex B.4 the pass-by time of Formula B.1 is that of half the unit, so pass half its length.

Parameters

Returns: $T_p$, in seconds.

Raises

pass_by_uncertainty(
    reading_db: float,
    inputs: Sequence[Quantity],
    *,
    coverage_factor: float = 2.0,
) -> PassByUncertainty

The uncertainty of a rolling stock noise result, Annex G.

The standard uncertainties of the input quantities combine as

(Formulae G.5 and G.6), and their mean value corrections, which Table G.1 gives for the unsymmetrical ranges, are added to the reading. An input known only by its limits $\pm a$ has $u=a/\sqrt{3}$ (Formula G.2): build it with phonometry.metrology.rectangular.

Parameters

Returns: The budget.

Raises

PassByMeasurement(
    times_s: NDArray[np.float64],
    levels_db: NDArray[np.float64],
    start_s: float,
    end_s: float,
    equivalent_level_db: float,
    max_level_db: float,
    front_level_db: float,
    rear_level_db: float,
    record_start_level_db: float,
    record_end_level_db: float,
    pass_by_time_s: float | None = None,
)

The levels of one pass-by record, 6.5 and 6.6.3.

Parameters

property

How far the record ends below the level at the rear, in dB (6.6.3).

property

The single event level $L_{p\mathrm{Aeq},T}+10\lg (T/T_0)$, $T_0=1$ s (2005, Formula 7).

property

$T=T_2-T_1$, in seconds.

property

The energy of the interval spread over $T_p$, in dB; None without it.

$10\lg (\frac{1}{T_p}{\int }_T{p}_{\mathrm{A}}^2/p_0^2\mathrm{d}t)$: the transit exposure level of ISO 3095:2005 3.14 for a whole train, and the $L_{p\mathrm{Aeq},T_p}$ of Formula B.1 for a single trailer unit, whose $T_p$ is that of half the unit.

PassByMeasurement.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the level history with the measurement interval, as Figure 7 does.

Parameters

Returns: The axes drawn on.

property

Whether the record starts and ends at least 10 dB down, 6.6.3.

property

How far the record starts below the level at the front, in dB (6.6.3).

PassByUncertainty(
    reading_db: float,
    names: tuple[str, ...],
    corrections_db: tuple[float, ...],
    standard_uncertainties_db: tuple[float, ...],
    coverage_factor: float = 2.0,
)

An uncertainty budget of a rolling stock noise result, Annex G.

The measurand is the reading plus uncorrelated corrections, $Y=\sum X_i$ (Formula G.1), so every sensitivity coefficient is 1 (Formula G.4).

Parameters

property

$u_{\mathrm{c}}(y)=\sqrt{\sum u^2(x_i)}$, Formula G.5, in dB.

property

$U=k{u}_{\mathrm{c}}(y)$, Formula G.6, in dB.

property

The result $y$, the reading plus every mean value correction, in dB.

PassByUncertainty.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw each input’s share of the variance, largest first, as Figure G.1.

Parameters

Returns: The axes drawn on.

property

Each input’s share of the variance of the result, as Figure G.1 draws it.

Constant (tuple).

PREFERRED_PASS_BY_SPEEDS_KMH = (20.0, 40.0, 60.0, 80.0, 100.0, 120.0, 140.0, 160.0, 200.0, 250.0, 300.0, 320.0, 350.0)

Constant (mapping).

REFERENCE_TRACK_DECAY_LIMITS_DB_PER_M = {'vertical': {250.0: 2.0, 315.0: 2.0, 400.0: 6.0, 500.0: 6.0, 630.0: 6.0, 800.0: 2.19, 1000.0: 0.8, 1250.0: 0.8, 1600.0: 0.8, 2000.0: 0.8, 2500.0: 0.8, 3150.0: 0.8, 4000.0: 0.8, 5000.0: 0.8}, 'lateral': {250.0: 2.04, 315.0: 1.38, 400.0: 0.94, 500.0: 0.64, 630.0: 0.43, 800.0: 0.29, 1000.0: 0.2, 1250.0: 0.2, 1600.0: 0.32, 2000.0: 0.5, 2500.0: 0.5, 3150.0: 0.5, 4000.0: 0.5, 5000.0: 0.5}}

Constant (mapping).

REFERENCE_TRACK_ROUGHNESS_LIMIT_DB = {0.4: 17.1, 0.315: 15.0, 0.25: 13.0, 0.2: 11.0, 0.16: 9.0, 0.125: 7.0, 0.1: 4.9, 0.08: 2.9, 0.063: 0.9, 0.05: -1.1, 0.04: -3.2, 0.0315: -5.0, 0.025: -5.6, 0.02: -6.2, 0.016: -6.8, 0.0125: -7.4, 0.01: -8.0, 0.008: -8.6, 0.0063: -9.2, 0.005: -9.8, 0.004: -10.4, 0.00315: -11.0}

ReferenceTrackCheck(
    speed_kmh: float,
    roughness: tuple[AcousticRoughnessSpectrum, ...],
    decay_rates: tuple[TrackDecayRate, ...],
    roughness_limit_db: Mapping[float, float],
    decay_limits_db_per_m: Mapping[str, Mapping[float, float]],
    small_deviations: SmallRoughnessDeviation | None = None,
    *,
    curve_radius_m: float | None = None,
    track_gradient_ratio: float | None = None,
)

The verdict on a test track against the reference conditions of ISO 3095 6.2.

Parameters

conditions, passes and failed are read from these fields and the limits of 6.2, so none of them is a field.

property

Every requirement judged, in the order of the clause.

Read from the roughness, the decay rates, the limits, the Annex C verdict and the radius and gradient when given.

property

The requirements that do not hold.

property

Whether every requirement judged holds and none was left unjudged for want of data.

The curve radius and the gradient are judged only when given; the roughness and both decay rates are always required, and so is the length of a line analysed by EN 15610 Method B.

ReferenceTrackCheck.plot(
    ax: Axes | None = None,
    *,
    panel: str = 'roughness',
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the roughness spectra against Figure 2, or the decay rates against Figure 3.

Parameters

Returns: The axes drawn on.

RiseSpeedResult(
    times_s: NDArray[np.float64],
    levels_db: NDArray[np.float64],
    slopes: tuple[tuple[int, int], ...],
    rise_speeds_db_per_s: tuple[float, ...],
)

The impulsive character of a level history, Annex A.

Parameters

RiseSpeedResult.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the history with the slopes that count and the steepest rise.

Parameters

Returns: The axes drawn on.

property

The rise speed $s=\max (s_j)$, in dB/s; None when no slope rises 10 dB.

rolling_stock_test(
    samples_db: Mapping[str, ArrayLike],
    *,
    method: str = 'constant_speed',
) -> RollingStockTestResult

The result of a constant-speed, starting or braking test, 6.7.1, 7.5.4, 7.6.4, 8.7.

Each position’s runs are averaged arithmetically and rounded to the nearest integer decibel, and the result is the highest of those: the louder side at constant speed and in the averaged level method, the loudest position in the maximum level method and in braking. A speed normalisation, when one is required, goes on the runs before this (6.7.1).

Parameters

Returns: The test.

Raises

Constant (tuple).

ROLLING_STOCK_TEST_METHODS = ('constant_speed', 'acceleration_maximum', 'acceleration_averaged', 'braking')

RollingStockTestResult(
    method: str,
    samples_db: Mapping[str, tuple[float, ...]],
)

A test decided by the highest rounded mean of three runs per position.

Parameters

property

The test result: the highest rounded mean (6.7.1, 7.5.4, 7.6.4, 8.7).

property

The position whose rounded mean is the result, the first on a tie.

property

The arithmetic mean of each position’s runs, in dB, unrounded.

RollingStockTestResult.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw every run, each position’s rounded mean and the result.

Parameters

Returns: The axes drawn on.

property

The positions, in the order given.

property

Each position’s mean rounded to the nearest integer decibel.

property

The spread of each position’s runs, in dB (9.3).

property

Whether every position’s runs lie within 3 dB of each other (9.3).

When they do not, 9.3 asks for more runs; braking with squeal may not get there, and 8.7 NOTE 1 then reports the runs without a mean.

roughness_comparability(
    roughness_1: AcousticRoughnessSpectrum,
    roughness_2: AcousticRoughnessSpectrum,
    noise_levels_1_db: ArrayLike,
    noise_levels_2_db: ArrayLike,
    *,
    frequencies_hz: ArrayLike,
    speed_kmh: float,
) -> RoughnessComparability

Bound how much the roughness of two tracks could change a pass-by level, Annex E.

E.2.1. The minimum and maximum envelopes of the two measured roughness spectra are taken band by band (Formula E.1). E.2.2. The two measured spectra and the two envelopes are carried to frequency at the train speed as in Annex C, and each measured spectrum gets two correcting spectra, its difference from each envelope (Formula E.2). E.2.3. Each situation’s noise spectrum is revised by its two corrections (Formula E.3), the energy-summed difference of measured and revised gives $\Delta L^{\min ,i}\ge 0$ and $\Delta L^{\max ,i}\le 0$ (Formula E.4), and the bound is the largest of their magnitudes (Formula E.5). It is an approximate bound for roughness alone, not a prediction (E.1).

Parameters

Returns: The four differences and the bound.

Raises

RoughnessComparability(
    speed_kmh: float,
    roughness_1: AcousticRoughnessSpectrum,
    roughness_2: AcousticRoughnessSpectrum,
    frequencies_hz: NDArray[np.float64],
    noise_levels_1_db: NDArray[np.float64],
    noise_levels_2_db: NDArray[np.float64],
    level_differences_db: tuple[float, float, float, float],
)

How much two tracks’ roughness could change a pass-by level, Annex E.

Parameters

property

$\Delta L_{p\mathrm{Aeq},T_p}$ of Formula E.5, in dB.

The largest magnitude of the four differences: the most the roughness difference between the two situations could change the pass-by level.

property

The maximum envelope of the two roughness spectra, Formula E.1.

property

The minimum envelope of the two roughness spectra, Formula E.1.

RoughnessComparability.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the two roughness spectra and their envelopes, as Figure E.1.

Parameters

Returns: The axes drawn on.

SmallRoughnessDeviation(
    speed_kmh: float,
    roughness: AcousticRoughnessSpectrum,
    limit_db: Mapping[float, float],
    corrected_roughness_levels_db: NDArray[np.float64],
    frequencies_hz: NDArray[np.float64],
    roughness_correction_db: NDArray[np.float64],
    noise_levels_db: NDArray[np.float64],
)

The acceptance of small roughness exceedances by their effect on the noise, Annex C.

Parameters

property

Whether the measured roughness exceeds the limit in any band at all.

property

$\Delta L_{p\mathrm{Aeq},T_p}$ of Formula C.4, in dB.

The energy sum of the measured spectrum less that of the revised one: an upper bound on what the exceedance added to the pass-by level.

property

Whether the effect is at most 1 dB, C.3.

SmallRoughnessDeviation.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the measured and revised noise spectra and the correction.

Parameters

Returns: The axes drawn on.

property

$L_{p\mathrm{Aeq},T_p}^{\mathrm{revised}}(f)$ of Formula C.3, in dB.

Constant (float).

STATIONARY_END_POSITION_LENGTH_M = 11.780972450961723

stationary_test(
    levels_db: ArrayLike,
    lengths_m: ArrayLike,
) -> StationaryTestResult

The stationary test of a unit from its measured mesh, 5.7 and 5.8.1.

Each set gives the unit level of Formula 1, and the result is the mean of the sets rounded to the nearest integer decibel (StationaryTestResult.reported_level_db). The samples of a position are valid when they are no more than 3 dB apart (9.3).

Parameters

Returns: The test.

Raises

stationary_unit_level(levels_db: ArrayLike, lengths_m: ArrayLike) -> float

The length-weighted energy average of a stationary mesh, Formulae 1 to 3.

over the positions of the whole unit (Formula 1) or of one car (Formula 3). The mesh is the whole one of 5.5.1.1 before any reduction: an omitted position takes the level of the equivalent one measured (5.5.1.2), and an end position stands for STATIONARY_END_POSITION_LENGTH_M.

Parameters

Returns: The average, in dB, unrounded.

Raises

StationaryTestResult(
    levels_db: NDArray[np.float64],
    lengths_m: NDArray[np.float64],
)

The stationary test of a unit, 5.8.1.

Parameters

property

The arithmetic mean of the set levels, in dB, unrounded.

StationaryTestResult.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the level of every position and the unit level.

Parameters

Returns: The axes drawn on.

property

The spread of the samples of each position across the sets, in dB (9.3).

property

The test result: the mean rounded to the nearest integer decibel (5.8.1).

property

$⟨L_{p\mathrm{Aeq},T}{⟩}_{\mathrm{unit}}$ of each set, Formula 1, in dB.

property

Whether every position’s samples lie within 3 dB of each other (5.7, 9.3).

TrackCondition(
    clause: str,
    requirement: str,
    holds: bool | None,
    detail: str,
)

One requirement of the reference track and whether it holds.

ReferenceTrackCheck.conditions builds these rows from the track it holds each time it is read; no verdict reads a row built elsewhere.

Parameters

transit_exposure_level(
    equivalent_level_db: float,
    *,
    measurement_time_s: float,
    pass_by_time_s: float,
) -> float

The transit exposure level of a train, ISO 3095:2005 3.14.

(Formula 10): the energy of the whole passage, measured over a time $T$ that runs from 10 dB below the level at the front to 10 dB below the level at the rear, spread over the pass-by time $T_p$ alone. It is Formula 9’s $\mathrm{SEL}+10\lg (T_0/T_p)$ written with the equivalent level.

Parameters

Returns: TEL, in dB.

Raises

type_test_speeds(max_speed_kmh: float) -> tuple[float, ...]

The speeds a unit is type tested at, 6.6.2.

Above 80 km/h, at 80 km/h and at the maximum speed; at or below it, at the maximum speed alone. Further tests are run at the preferred speeds of PREFERRED_PASS_BY_SPEEDS_KMH.

Parameters

Returns: The type-test speeds, in km/h, slowest first.

Raises