A timestamp, using the Barycentric Dynamical Time scale (TDB), to denote the time of exposure start (Modified Julian Date).
| Attribute | Value |
|---|---|
| data type | float |
| enumerated Values | not defined |
| units | days |
| example | 58086.50347 |
| default value | |
| special processing | OPTIONAL |
| source | Ephemeris |
| software source | |
| calculation | |
| DB destination | ['ScienceCommonExt.tdb_beg'] |
| data type in DB | float |
| instrument | ALL |
| mode | All |
| product level | 1b |
| FITS hdu | SCI |
| FITS header section |