NEID DRP Version History

Versioning Style

The NEID Data Reduction Pipeline uses Semantic Versioning of format X.Y.Z (Major.Minor.Patch). The pipeline team does not recommend mixing processed data from different minor versions. Within a minor version, data from different patch versions is compatible.

Upon release of a new Major or Minor version, all NEID data will be reprocessed. Upon release of a new Patch version, only data affected by the patched code will be reprocessed.

Release History

Patch version v1.5.2 was released February 16, 2026 and contains several small changes that allow dates with compromised or non-standard calibration sequences to process without crashing. This release should not affect calculation of RVs or other derived products, and is backwards compatable with all v1.5.x releases.

Patch version v1.5.1 was released February 2, 2026 and contains a single change to the top level config file that determines the LFC frame vetting for HE mode. The maximum average FWHM value is raised from 9 to 15 pixel for HE mode to reduce the number of nights that fallback to the master wavelength solution in HE mode in 2025B. No publicly available data is reduced with v1.5.0

Minor version v1.5.0 was released February 1, 2026 and contains two major updates as well as a variety of smaller patches and bugfixes:

  • The wavelength solution module was significantly updated to be more robust against variations in the LFC flux and bandwidth. LFC modes are vetted mode by mode, instead of frame by frame, and the wavelength solution coefficients for each order can be significantly restricted to limit changes in the derived wavelength solution to RV shifts only when an order is identified as “bad” from a large number of modes failing the vetting procedure.

  • The Level 2 files now include three additional HDU extensions that contain a stitched spectrum (and corresponding wavelength and variance arrays), interpolated to a uniform log-lambda grid. This spectrum should be utilized with care, and not used for any applications requiring high radial velocity precision measurements.

Patch version v1.4.2 was released in April 2025 and contains the following change:

  • Handle HE fiber calibration sequences when one of the HE fibers (e.g., Sky) has all LFC frames fail vetting but the other HE fiber (e.g., Sci) passes vetting.

Patch version v1.4.1 was released in February 2025 and contains the following significant changes:

  • Handle calibration sequences when only a single LFC passes quality control checks

  • Handle a bug where missing flat fields result in zeros for part or all of the extracted spectrum flux

  • Changes the blue wavelength edge of the LFC that is used for wavelength solutions and drift correction after installation of the new PCF in August 2024 to be order index 40 (echelle order 134) @ 458nm. In v1.4.0 this was index 30 (echelle order 144) @ 426nm. See below for more details.

Minor version v1.4.0 was released in December 2024 and contained substantial updates to the algorithms used to derive the wavelength calibrations, nightly drift measurements, CCFs, and other derived products. This verison incorporated vetting the LFC exposures based on the quality of the fits to the ensemble of LFC lines. This has increased the reliability of the derived wavelength calibrations.

The DRP Team recommends that data from August 26, 2024 onward (semester 2024B) only be used with v1.4.1 or later. Data prior to this can be used in any v1.4.x version. Users are encouraged to discard any data from 2024B that was processed with v1.4.0. All 2024B data will be reprocessed upon release of v1.4.1. The latest version, v1.4.2, is a patch release to fix a wavelength calibration bug that prevented the processing of a handful of nights. Otherwise, v1.4.1 and v1.4.2 are functionally equivalent.

For details on versions v1.3.x and earlier, see the CHANGELOG.

Last Updated: 2026-02-16, CFB