DFFAttitudeTarget:

------------------------------------------------------------------------
   Generate a reference quaternion for a variety of targets. There
   are six types of target

   'latlon'   - point a spacecraft vector at a specific latitude
                and longitude of the earth. The angle about
                the vector is ignored
   'sun'      - point a spacecraft vector at the sun. The angle about
                the vector is ignored
   'lvlh'     - align the spacecraft with LVLH 
   'eci'      - align with respect to ECI
   'ulvlh'    - align with a unit vector defined in the lvlh frame
   'ueci'     - align with a unit vector defined in the eci frame
   'target'   - align with a target spacecraft

   The output is the target qECIToBody.

   Since version 7.
------------------------------------------------------------------------
   Form:
   qTarget = FSWAttitudeTarget( type, d, t )
------------------------------------------------------------------------

   ------
   Inputs
   ------
   type    (1,:)     Type of target
                   
   d       (1,1)     Data structure with spacecraft information
                     .qECIToBody    (4,1) Current quaternion
                     .rECI          (3,1) ECI position vector
                     .vECI          (3,1) ECI velocity vector
                     .jD            (1,1) Julian date

   t       (1,1)     Data structure with target information
                     .latitude      (1,1) Geodetic latitude (rad)
                     .longitude     (1,1) Longitude (rad)
                     .u             (3,1) Unit vector in the body frame
                     .qOffset       (4,1) Offset quaternion (lvlh and eci only)
                     .uTarget       (3,1) Target vector in the reference frame
    INVALID:         .rTarget       (3,1) Target ECI position vector

   -------
   Outputs
   -------
   qTarget (4,1)     Target qECIToBody

------------------------------------------------------------------------

Children:

AeroUtils: Coord/LatLonToR
AeroUtils: Coord/QLVLH
Common: General/DeBlankLT
Common: Quaternion/QForm
Common: Quaternion/QMult
Common: Quaternion/QTForm
Common: Quaternion/U2Q
Common: Time/JD2T
Math: Linear/Unit
OrbitMiniToolbox: Support/TruEarth
SC: Ephem/SunV1