# MIDL — Merged Interplanetary Data from L1 (University of Michigan)

Multi-spacecraft solar-wind merge at the Sun–Earth L1 point: ACE, DSCOVR,
Wind, and SOLAR-1 blended into a single 1-minute product, 1998–present,
GSM coordinates, with ballistic and 1-D MHD propagation toward Earth.
The archive is rebuilt monthly; a realtime feed updates every 5 minutes.

## Data access

- Download page: https://csem.engin.umich.edu/MIDL/download.html
  (JavaScript-rendered; the routes below serve the same archive directly)
- Python client (preferred):

      pip install csem-midl

      import midl
      data = midl.load("2005-01-01 00:00", "2005-01-02 00:00", 32)
      # 3rd arg = target: "L1", or geocentric distance in Re
      #   (14 = bow-shock nose / OMNI convention, 32 = SWMF Geospace)
      # method="ballistic" (default) or "mhd"
      # returns an xarray Dataset; caches locally;
      # midl.to_csv() / midl.to_dat() exporters

- Direct monthly CSV files (static, no auth, {YYYY}/{MM} zero-padded):

      https://csem.engin.umich.edu/MIDL/data/{YYYY}/{MM}/{YYYYMM}_L1.csv
      https://csem.engin.umich.edu/MIDL/data/{YYYY}/{MM}/{YYYYMM}_14Re.csv
      https://csem.engin.umich.edu/MIDL/data/{YYYY}/{MM}/{YYYYMM}_32Re.csv
      https://csem.engin.umich.edu/MIDL/data/{YYYY}/{MM}/mhd/{YYYYMM}_mhd_{RRR}Re.csv
      (RRR = zero-padded geocentric distance in Re, e.g. 014, 032)

- Realtime feed (5-minute cadence), manifest-as-commit:

      https://csem.engin.umich.edu/MIDL/realtime/realtime_manifest.json

## Documentation

- Data format — columns, units, GSM frame, source flags:
  https://csem.engin.umich.edu/MIDL/format.html
- Merge algorithm: https://csem.engin.umich.edu/MIDL/algorithm.html
- Realtime feed description: https://csem.engin.umich.edu/MIDL/realtime.html

## Code

- Pipeline source: https://github.com/connordimarco/MIDL
- Python client source: https://github.com/connordimarco/CSEM-MIDL
- PyPI: https://pypi.org/project/csem-midl/

## Citation & contact

- Dataset DOI: https://doi.org/10.5281/zenodo.19742679
- Citation details and contact: https://csem.engin.umich.edu/MIDL/resources.html

## Related

- MSWIM2D — these data propagated through the heliosphere (1–75 AU):
  https://csem.engin.umich.edu/MSWIM2D/llms.txt