NEID Data Bitfields

Overview

Beginning in v1.2.0, the NEID DRP uses bitfields contained in header keywords DQLEVEL0, DQLEVEL1, DQLEVEL2 to compactly provide information about the data that may be useful to end users. This data is packaged as a series of nested bit-fields, as defined below, and stored in the header as an int. Each field contains up to 64 bits, although many will be unpopulated (i.e., 0).

Each byte is dedicated to a specific DRP subsystem, and the 2 least-significant-bits of each byte contain rollup assessments of the data in the following 6 bits.

The least-significant-byte contains rollup information from the other bytes. Bits 0-1 contain an overall data quality assessment, as follows:

• 0: Pass

• 1: Warn

• 2: Fail

Bits not listed in the below tables are reserved for future use.

DQLEVEL0

Not currently used

DQLEVEL1

Byte	Bit	Description
0	0-1	Overall Level 1 Summary Assessment 0: Pass 1: Warning 1: Rejected
1		Manual Assessment Bits
1	8-9	Summary Assessment 0: No known faults 1: Data warning 2: Data rejected
1	10-15	Assessment Flag (from manual assessment masterfile) 0: No flags specific 1-15: Header fault description 1: Major header telemetry fault 16-32: Image fault description 33-47: Instrument/Port fault description 33: CFB camera fault 48-63: Other fault description 48: Telescope summer shutdown 49: Telescope engineering 50: Shared Risk - General 51: Shared Risk - Commissioning 52: Shared Risk - Contreras Fire Restart 54: Etalon stabilizing (possible unreliable wavecal) 54: LFC fault (possible unreliable wavecal) 58: Solar telescope fault - cable wrap fail, bad RVs 59: Solar eclipse 60: Wrong star was observed
2		Automated Hardware Assessment
2	16-17	Summary Assessment
2	18	Port illumination failure
2	19	Calibration illumination failure
3		Run Information/Manifest
3	24-25	Summary Assessment (based on OBSTYPE) 0: Sci, Cal, Eng 1: Tst
3	26-27	Specific Observation Type (Header Keyword OBSTYPE) 0: Sci 1: Cal 2: Eng 3: Tst
4		CCD Image Processing Assessment
4	32-33	Summary Assessment
4	34	Bias contamination 0: Pass 1: Fail
5		Extraction
5	40-41	Summary Assessment
5	42	Signal-to-noise Threshold (>= 80% of Requested) 0: Pass 1: Fail
6		Wavelength Calibration
6	48-49	Summary Assessment 0: WAVECAL = LFCplusThAr AND DRIFTFUN = dailymodel0 1: Otherwise
6	50	Wavelength Calibration Mode (Header Keyword WAVECAL) 0: LFConly 1: LFCplus ThAr
6	51	Session Drift Correction Model (Header Keyword DRIFTFUN) 0: Master 1: Constant 2: Linear 3: Simultaneous 4: DailyModel0

DQLEVEL2

Byte	Bit	Description
2		Telluric Model
2	16-17	Summary Assessment
2	18	Preciptable water vapor fit status: 0: Succeeded 1: Failed

Last Updated, 2025-02-18, DMK