This file contains information on the offsets of the various instrument apertures with respect to the Quadrant Star Sensor (QSS). It was of fundamental importance in calculating instrument fields of view.
The IFPG file contains a primary header with the fields described in Table D.28. In this example non-mandatory fields are filled with example values.
| Keyword | Value | Description |
| SIMPLE = | T | / |
| BITPIX = | 8 | / |
| NAXIS = | 0 | / |
| EXTEND = | T | / |
| ORIGIN = | 'ESA ' | / European Space Agency |
| TELESCOP = | 'ISO ' | / Infrared Space Observatory |
| COMMENT | ISO Focal Plane Geometry | |
| FILENAME = | 'IFPG ' | / File name in archive |
| DATE = | '09/07/95' | / Creation date |
| FILEVERS = | '0298 ' | / Version ID in ISO archive |
| OLPVERS = | 'OLP_21 ' | / SOC OLP system version |
| USERNAME = | 'PIPELINE' | / |
| DATE-OLD = | '1996-08-14' | / Date of original creation by IDT |
The IFPG file contains records described in Table D.29.
| Keyword | Number | Format | Description |
| SPARE | 17 | I1 | Spare |
| INSTID | 1 | A1 | Instrument ID (C,L,P,S) |
| APERTID | 1 | I2 | Aperture ID (1/2/3) |
| DY | 1 | R4 | Aperture Y-offset with respect to QSS, in arcmin |
| DZ | 1 | R4 | Aperture Z-offset with respect to QSS, in arcmin |
| REV | 1 | I4 | Revolution during which the offsets were measured |
 1 = EE1 tests |
|||
| 2 = EE2 tests |