Card 9 - ALIGN Align Vector Definition

This optional card defines the alignment of a vector with an orbit dependent direction.

Parameters: KODE, N1, T1, T2, T3

KODE

KODE is the code ALIGN (or 62)

N1

N1 is a joint number (N1 from a Card 9 JOINT).

T1

T1 is the orbit dependent direction defined on a Card 6t ORBDEF1 (NADIR, SUN, STAR, PVEL, PNORMAL, NORTH or SOUTH) which vector T2 is aligned with.

T2

T2 is a vector number (N1 from Card 9 - VECTOR Vector Definition).

T3

T3 may be:

  • T3 = ALL for all defined orbit and modeling requests
  • An ID number from an ORBDEF Card for single orbit and attitude modeling requests

Code example


 $ ALIGN VECTOR 2 WITH NORTH FOR ALL ORBITS
 JOINT        1 REVOLUT 0 1
 VECTOR       1 0 0 0 -1 0 0
 VECTOR       2 0 0 0 0 1 0
 ARTICUT      1 SHELLS

Notes

The ALIGN option minimizes the angle between the align vector and the vector to the object being pointed to, while respecting the constraints of the rotational joint. It requires Card 9 ARTICUT, JOINT, VECTOR and Card 6 orbit definition to be present in INPF. An orbit is defined with either Card 6t ORBDEF, or Card 6b SOL card and Card 6d EARTH.