HST Apertures Documentation:

Simplified SIAF Tables:
Positions, orientations, and scales extracted from the Science Instrument Aperture File (SIAF).

Instrument Science Reports:
ISRs are technical reports written by members of the Observatory Group about various aspects of the instrument and data. They usually contain in-depth information about specific topics.

NICMOS SM-2 SMOV Alignment Results
OSG-CAL-97-04: NICMOS SM-2 SMOV Alignment Results.
O. Lupie 20 Jun 2002 (pdf)

Transforming Non-COSTAR Aperture Positions to the New Vehicle Reference
OSG-CAL-96-06: A major effect of the on-orbit FGS to FGS re-alignment of day 105 1996, was the redefinition of the vehicle reference frame...
M. Lallo 20 Jun 2002 (pdf)

FAQs:
Frequently Asked Questions.