TMEASURE is a pixel-based time in seconds between the first and last measurements along a ramp or integration, multiplied by the number of integrations. It represents the longest possible time interval used by the pipeline to perform an up-the-ramp fit. Ramps with identified cosmic rays and/or that incur saturation have shorter effective measurement times than this. This is the time at the core of the ETC calculations of signal-to-noise ratios (with similar caveats on cosmic rays and saturation).
| Attribute | Value |
|---|---|
| data type | float |
| enumerated Values | not defined |
| units | seconds |
| example | 1000.0 |
| default value | |
| special processing | VALUE_REQUIRED |
| source | Science Data Processing (SDP) |
| software source | |
| calculation | TGROUP * (NGROUPS - 1) * NINTS |
| DB destination | ['ScienceCommon.tmeasure', 'GuideStar.tmeasure'] |
| data type in DB | float |
| instrument | ALL |
| mode | All |
| product level | 1b |
| FITS hdu | PRIMARY |
| FITS header section | Exposure |