This file contains the history of the aperture pointing when the spacecraft was in Programmable Pointing Mode (PPM), normally around perigee passage. History of the aperture pointing in this mode does not appear in the APPH file. It was routinely used to calculate the evolving pointing history of the spacecraft pointing in the IIPH or CIPH near the beginning and end of an orbit.
The APPM file contains a primary header with the fields described in Table D.8. 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 | Attributes of instantiated Observations | |
FILENAME = | 'APPM ' | / File name in ISO archive |
DATE = | '09/07/95' | / Creation date |
FILEVERS = | '0298 ' | / Version ID in ISO archive |
OLPVERS = | 'OLP_21 ' | / SOC OLP system version |
CALGVERS = | 'CALG_31 ' | / SOC OLP CAL-G files version |
USERNAME = | 'PIPELINE' | / |
CREATOR = | 'MAKE_APPM v1.0' | /Application that created the file |
DATE-OLD = | '1999-08-16' | / Date of original creation by IDT |
The APPM file contains records described in Table D.9.
Keyword | Number | Format | Description |
POFUTS | 1 | A11 | / Planned start time of PPM episode |
EPISODE | 1 | A9 | / 'PPM_EXIT' or 'PPM_ENTRY' |
INDEX | 1 | A9 | / PPM index number |
APERTURE | 1 | A2 | / Aperture in use = `X0' |
REQTYPE | 1 | A1 | / Type of pointing request = `X' |
UTCS | 2 | I4 | / UTC time key of actual PPM start |
UTCE | 2 | I4 | / UTC time key of actual PPM end |
UTKS | 1 | I4 | / UTK time key of actual PPM start |
UTKE | 1 | I4 | / UTK time key of actual PPM end |
RA | 1 | R8 | / RA of reference PPM direction, in degrees |
DEC | 1 | R8 | / DEC of reference PPM direction, in degrees |
ROLL | 1 | R8 | / ROLL of reference PPM direction, in degrees |
STRQ | 4 | R8 | / Reference Star-Tracker quaternion |
REV | 1 | I4 | / Revolution |
LENGTH | 1 | I4 | / Number of PPM AOCS frames |
SPARE | 1 | 8A | / Spare |