See v1.0 Record Format Tables for the record structure outside of payload.
| Offset | Length | Type | Description |
| byte | byte | ||
| 16 | 16 | character | data type |
| 32 | 12 | character | base time in format like "date +%Y%m%d%H%M" |
| 44 | 4 | integer | base time in sequential minute from 1801-01-01T000Z |
| 48 | 4 | character | time unit for valid times |
| 52 | 4 | integer | n_dc: number of members |
| 56 | 4 | integer | n_vt: number of valid times |
| 60 | 4 | integer | n_lv: number of planes |
| 64 | 4 | integer | n_el: number of elements |
| 68 | 4 | character | map projection |
| 72 | 2 * 4 | integer [2] | number of grid points in X and Y directions |
| 80 | 2 * 4 | floating [2] | grid index of reference point |
| 88 | 2 * 4 | floating [2] | latitude/longitude of reference point |
| 96 | 2 * 4 | floating [2] | latitude/longitude distance between grid points |
| 104 | 2 * 4 | floating [2] | 1st STD latitude/longitude of map projection |
| 112 | 2 * 4 | floating [2] | 2nd STD latitude/longitude of map projection |
| 120 | 2 * 4 | floating [2] | 3rd STD latitude/longitude of map projection |
| 128 | 2 * 4 | floating [2] | 4th STD latitude/longitude of map projection |
| 136 | 4 | character | PVAL: representation method of grid |
| 140 | 2 * 4 | --- | reserved for future use of map projection |
| 148 | 6 * 4 | --- | reserved for future use |
| 172 | n_dc * 4 | character [n_dc][4] | list of member name |
| (1) | n_vt * 8 | integer [2][n_vt] | list of valid time pair |
| (2) | n_lv * 12 | character [2][n_lv][6] | list of plane pair |
| (3) | n_el * 6 | character [n_el][6] | list of element name |