OpticalNavigationMeasurement:

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   Computes three optical measurements.
   This routine computes up to 5 measurements. You enter information
   in g for up to 2 planets. The data is

   vector from the reference center to planet 1
   radius of planet 1
   star near planet 1
   vector from the reference center to planet 2
   radius of planet 2
   star near planet 2

   The first two are required. The remainder are optional
   You will get the following angular measurements

   chord of planet 1
   angle between star and planet 1
   chord of planet 2
   angle between star and planet 2
   angle between planet 1 and planet 2

   Type OpticalNavigationMeasurement for a demo. The demo rotates the
   spacecraft around the center but everything else is fixed.
   
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   Form:
   y = OpticalNavigationMeasurement( x, g )
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   Inputs
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   x     (n,1) [x;y;z;...]
   g     (1,1) Data structure 
               .l1                  (3,1)   Vector to planet 1
               .a1                  (1,1)   Planet 1 radius
               .u1                  (3,1)   Unit vector to star 1*
               .l2                  (3,1)   Vector to planet 2*
               .a2                  (1,1)   Planet 2 radius*
               .u2                  (3,1)   Unit vector to star 2*
                                            *optional

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   Outputs
   -------
   y     (5,1) Measurement [chord1;star/planet1;chord2;star/planet2;planet/planet]

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Children:

Common: Database/Constant
Common: Graphics/Plot2D
Common: Math/Mag
Common: Math/Unit