# Backscattering Experimental Data

Python interface of experimental data for measurements of backscattered light in
the Virgo interferometer. It can be executed on Cascina server to load online
data, or use local [hdf5](https://www.hdfgroup.org/solutions/hdf5/) file.

## Getting started

This project use [uv](https://docs.astral.sh/uv/) to manage
dependencies, and [mise](https://mise.jdx.dev/) to manage python
version and virtual environment.

> [!NOTE]
> You can still use pip to manage dependencies using [pyproject.toml](pyproject.toml)

## Example

```py
from backscattering_experimental_data.factory.initializer import (
    InitializerComponent,
    InitializerScatterer,
)
from backscattering_experimental_data.factory.measurement import MeasurementFactory
from backscattering_experimental_data.root import Root
from backscattering_experimental_data.metadata import MetadataRoot, InjectionFactory
from gwpy.time import Time
from astropy.units import s, V, m, min, Hz, dimensionless_unscaled
from h5py import File

SR = InitializerComponent(
    name = "SR",
    calibration_factor = 1.15*m/V,
)
NE = InitializerComponent(
    name = "NE",
    calibration_factor = 0.97*m/V,
)

REF_LOW_NOISE_2 = MeasurementFactory.fetch(
    "Low Noise 2 - reference",
    "Reference data taken before the injection, in Low Noise 2",
    Time("2025-06-17T18:11:00.000000000", format="isot", scale="utc"),
    4 * min,
    [
        InitializerScatterer(
            name = "SDB1",
            calibration_factor = 1.15 * m / V,
            associated_component = SR,
            injection = None,
        ),
        InitializerScatterer(
            name = "SDB2",
            calibration_factor = 1.3 * m / V,
            associated_component = SR,
            injection = None,
        ),
        InitializerScatterer(
            name = "SWEB",
            calibration_factor = 0.97 * m / V,
            associated_component = NE,
            injection = None,
        ),
    ],
    True,
)
SDB1_LOW_NOISE_2 = MeasurementFactory.fetch(
    "Low Noise 2 - SDB1",
    "Injection of sine line in SDB1's suspension stage F0 in Low Noise 2 (SR is aligned)",
    Time("2025-06-17T18:23:00.000000000", format="isot", scale="utc"),
    4 * min,
    [
        InitializerScatterer(
            name="SDB1",
            calibration_factor=1.15*m/V,
            associated_component=SR,
            injection=InjectionFactory.make(
                type_="sin",
                amplitude=0.7 * dimensionless_unscaled,
                frequency=0.1 * Hz,
            ),
        ),
        InitializerScatterer(
            name="SDB2",
            calibration_factor=1.3*m/V,
            associated_component=SR,
            injection=None,
        ),
    ],
    True,
)
SWEB_LOW_NOISE_2 = MeasurementFactory.fetch(
    "Low Noise 2 - SWEB",
    "Injection of sine line on SWEB's SBE top stage in Low Noise 2 (SR is aligned)",
    Time("2025-06-17T18:53:00.000000000", format="isot", scale="utc"),
    15 * min,
    [
        InitializerScatterer(
            name = "SWEB",
            calibration_factor=0.97*m/V,
            associated_component=NE,
            injection=InjectionFactory.make(
                type_ = "sin",
                amplitude = 150 * dimensionless_unscaled,
                frequency = 0.2 * Hz,
            )
        ),
    ],
    True,
)
REF_LOW_NOISE_3_1 = MeasurementFactory.fetch(
    "Low Noise 3 - reference 1",
    "Reference data taken after going in Low Noise 3",
    Time("2025-06-17T19:21:00.000000000", format="isot", scale="utc"),
    5 * min,
    [
        InitializerScatterer(
            name = "SDB1",
            calibration_factor = 1.15 * m / V,
            associated_component = SR,
            injection = None,
        ),
        InitializerScatterer(
            name = "SDB2",
            calibration_factor = 1.3 * m / V,
            associated_component = SR,
            injection = None,
        ),
        InitializerScatterer(
            name = "SWEB",
            calibration_factor = 0.97 * m / V,
            associated_component = NE,
            injection = None,
        ),
    ],
    True,
)
SDB1_LOW_NOISE_3 = MeasurementFactory.fetch(
    "Low Noise 3 - SDB1",
    "Injection of sine line in SDB1's suspension stage F0 in Low Noise 3, so with SR misaligned",
    Time("2025-06-17T19:33:00.000000000", format="isot", scale="utc"),
    4 * min,
    [
        InitializerScatterer(
            name = "SDB1",
            calibration_factor = 1.15 * m / V,
            associated_component = SR,
            injection = InjectionFactory.make(
                type_ = "sin",
                amplitude = 0.7 * dimensionless_unscaled,
                frequency = 0.1 * Hz,
            ),
        ),
        InitializerScatterer(
            name="SDB2",
            calibration_factor=1.3*m/V,
            associated_component=SR,
            injection=None,
        ),
    ],
    True,
)
SWEB_LOW_NOISE_3 = MeasurementFactory.fetch(
    "Low Noise 3 - SWEB",
    "Injection of sine line on SWEB's top stage suspension in Low Noise 3 (SR misaligned)",
    Time("2025-06-17T19:51:29.000000000", format="isot", scale="utc"),
    5 * min + 31 * s,
    [
        InitializerScatterer(
            name = "SWEB",
            calibration_factor = 0.97 * m/V,
            associated_component = NE,
            injection = InjectionFactory.make(
                type_ = "sin",
                amplitude = 100 * dimensionless_unscaled,
                frequency = 0.2 * Hz,
            ),
        ),
    ],
    True,
)
REF_LOW_NOISE_3_2 = MeasurementFactory.fetch(
    "Low Noise 3 - reference 2",
    "Reference data taken after the SDB1 measurement in Low Noise 3",
    Time("2025-06-17T19:45:00.000000000", format="isot", scale="utc"),
    4 * min,
    [
        InitializerScatterer(
            name = "SDB1",
            calibration_factor = 1.15 * m / V,
            associated_component = SR,
            injection = None,
        ),
        InitializerScatterer(
            name = "SDB2",
            calibration_factor = 1.3 * m / V,
            associated_component = SR,
            injection = None,
        ),
        InitializerScatterer(
            name = "SWEB",
            calibration_factor = 0.97 * m / V,
            associated_component = NE,
            injection = None,
        ),
    ],
    True,
)
SDB2_LOW_NOISE_3 = MeasurementFactory.fetch(
    "Low Noise 3 - SDB2",
    "Injection of sine line on SDB2's top stage suspension to check if everything is working (still in Low Noise 3, so with SR misaligned)",
    Time("2025-06-17T20:07:38.000000000", format="isot", scale="utc"),
    7 * min + 12 * s,
    [
        InitializerScatterer(
            name = "SDB2",
            calibration_factor = 1.3 * m/V,
            associated_component = SR,
            injection = InjectionFactory.make(
                type_ = "sin",
                amplitude = 75 * dimensionless_unscaled,
                frequency = 0.1 * Hz,
            ),
        )
    ],
    True,
)

root = Root(
    metadata=MetadataRoot(
        name="Low Noise 2 & Low Noise 3 injections",
        description="These measurements were done in 2025-06-17 to check the difference of SDB1 fsc for SR misaligned and SR aligned. In Low Noise 2, SR is aligned, and in Low Noise 3, SR is misaligned. All the measurements are described in this logbook entry: https://logbook.virgo-gw.eu/virgo/?r=67027.",
    ),
    measurements=[
        REF_LOW_NOISE_2,
        SDB1_LOW_NOISE_2,
        SWEB_LOW_NOISE_2,
        REF_LOW_NOISE_3_1,
        SDB1_LOW_NOISE_3,
        REF_LOW_NOISE_3_2,
        SWEB_LOW_NOISE_3,
        SDB2_LOW_NOISE_3,
    ],
)

with File("mesure-juin-2025.hdf5", "w") as store:
    root = root.to_hdf5(store)
```

## License

This project is licensed under the GNU GPL v3+.
See [license file](LICENSE) for more information.

## Acknowledgment

Thanks to all the people that worked on [GWpy](https://gwpy.github.io)
and on all software and library used in this project.