astro-legacy-archive/gwosc-o2-strain

GWOSC O2 16 kHz gravitational-wave strain

This dataset contains the 16,384 Hz H1, L1, and V1 strain records released by the Gravitational Wave Open Science Center for the second observing run (O2). Each detector's 1 Hz data-quality and hardware-injection masks are separate configurations, preserving the source cadences.

How to use

The repository has H1-Strain, H1-DQmask, H1-Injmask, L1-Strain, L1-DQmask, L1-Injmask, V1-Strain, V1-DQmask, and V1-Injmask configurations. The examples below use an H1 data-quality span.

from datasets import load_dataset
mask = load_dataset("astro-legacy-archive/gwosc-o2-strain", "H1-DQmask", split="train", columns=["DQmask"], streaming=True)
print(next(iter(mask))["DQmask"])

0

import json
import pyarrow.parquet as pq
from huggingface_hub import hf_hub_download
path = hf_hub_download("astro-legacy-archive/gwosc-o2-strain", "H1-1171120128-1171124224-DQmask.parquet", repo_type="dataset")
print(json.loads(pq.read_metadata(path).metadata[b"timestream"])["schema"])

astro-legacy-archive/timestream

Dataset structure

Each Parquet file represents one contiguous observing span for one detector and one source dataset. Its filename has the form DETECTOR-GPS_START-GPS_STOP-COLUMN.parquet; GPS_STOP is exclusive. The three files for a detector and span contain strain, the data-quality mask, and the injection mask. Large strain spans are physically split into multiple Parquet files without changing their logical content.

The complete holding represents 15,171,584 advertised seconds of H1 data, 15,626,240 seconds of L1 data, and 1,929,216 seconds of V1 data. Real observing gaps divide each detector into spans. Parquet download sizes vary with span duration and content; the largest spans contain 124 H1, 81 L1, and 126 V1 source files.

The final H1 source file is asymmetric as served. Its filename and duration attribute advertise 4,096 seconds from GPS 1187733504. Its Strain dataset serves all 67,108,864 samples through GPS 1187737600, while each mask serves 114 values through GPS 1187733618, GWOSC's published O2 run boundary. The Parquet metadata records these served extents. The 65,241,088 strain samples after the mask extent are NaNs with float64 bits 0x7ff8000000000000; no strain samples are dropped and no mask samples are invented. This observation was made on 2026-09-03 from a fresh download with SHA-256 900dd722459216629e8676cf9bf731c3e017ff849a393c6c9d3aee54c94e15a0.

Integrity

The final holding at Hub revision 6d372583 contains 1,427 Parquet files and 3,714,985,065,804 bytes. Every path and byte length was checked against build-manifest.jsonl; every Hub LFS SHA-256 was checked against the corresponding fresh-download upload receipt. All 1,427 comparisons passed.

The source defines DQmask bits 0–6 as DATA, CBC_CAT1, CBC_CAT2, CBC_CAT3, BURST_CAT1, BURST_CAT2, and BURST_CAT3. It defines Injmask bits 0–4 as NO_CBC_HW_INJ, NO_BURST_HW_INJ, NO_DETCHAR_HW_INJ, NO_CW_HW_INJ, and NO_STOCH_HW_INJ. A set bit means that the named test passes or that the named hardware-injection type is absent. Treat each mask value as an integer bit mask rather than one Boolean.

Every file carries an astro-legacy-archive/timestream document in its Parquet schema metadata. It records sampling, detector, the represented HDF5 path and attributes, mask definitions, ordered source URLs and checksums, and structured regeneration provenance. PyArrow exposes this metadata directly; the datasets feature view retains column types but does not expose field or schema metadata.

Provenance

The source is GWOSC's O2_16KHZ_R1 HDF5 release: 3,704 H1 files, 3,815 L1 files, and 471 V1 files. Each file covers 4,096 seconds. The Parquet columns use the source HDF5 leaf names Strain, DQmask, and Injmask.

• —GWOSC O2 release
• —GWOSC O2 dataset archive
• —GWOSC O2 data release DOI
• —Open-data paper

This dataset contains the 16 kHz HDF5-derived products. GWOSC's separately distributed 4 kHz files and other formats are not configurations of this holding.

Considerations for use

• —Select DQmask and Injmask for the same detector and GPS interval as the strain being analysed.
• —Decode every 1 Hz mask value covering the analysis interval. One mask value applies to 16,384 strain samples.
• —Source strain samples may contain IEEE float64 NaNs where strain is not available; consult the masks before scientific use.
• —GPS time does not include leap seconds. Use a GPS-aware time library when converting to UTC.

Licensing and credit

GWOSC publishes this licence statement:

Data from this web site are licensed under a Creative Commons Attribution 4.0 International License.

GWOSC requests the following acknowledgement:

This research has made use of data or software obtained from the Gravitational Wave Open Science Center (gwosc.org), a service of the LIGO Scientific Collaboration, the Virgo Collaboration, and KAGRA. This material is based upon work supported by NSF's LIGO Laboratory which is a major facility fully funded by the National Science Foundation, as well as the Science and Technology Facilities Council (STFC) of the United Kingdom, the Max-Planck-Society (MPS), and the State of Niedersachsen/Germany for support of the construction of Advanced LIGO and construction and operation of the GEO600 detector. Additional support for Advanced LIGO was provided by the Australian Research Council. Virgo is funded, through the European Gravitational Observatory (EGO), by the French Centre National de Recherche Scientifique (CNRS), the Italian Istituto Nazionale di Fisica Nucleare (INFN) and the Dutch Nikhef, with contributions by institutions from Belgium, Germany, Greece, Hungary, Ireland, Japan, Monaco, Poland, Portugal, Spain. KAGRA is supported by Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan Society for the Promotion of Science (JSPS) in Japan; National Research Foundation (NRF) and Ministry of Science and ICT (MSIT) in Korea; Academia Sinica (AS) and National Science and Technology Council (NSTC) in Taiwan.

Citation

Please cite the GWOSC O1/O2 open-data paper:

@article{Abbott2021GWOSC,
  author = {{LIGO Scientific Collaboration} and {Virgo Collaboration}},
  title = {Open data from the first and second observing runs of Advanced LIGO and Advanced Virgo},
  journal = {SoftwareX},
  volume = {13},
  pages = {100658},
  year = {2021},
  doi = {10.1016/j.softx.2021.100658},
  eprint = {1912.11716},
  archivePrefix = {arXiv}
}

Errata and requests

To report an erratum, propose a correction, or ask a question about this dataset, open a Discussion or Pull Request in its Community tab; posting requires a free Hugging Face account. Dataset requests and archive-wide questions may be posted in the Community tab of any dataset.