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   Models a pinhole camera. Projects the catalog into the camera frame.
   This model does not account for lense effects. The function includes
   a noise model that accounts for random intensity variations, random
   centroid shifts and false stars.
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   Form:
   [starMeasurement, camera] = PinholeCamera( bCatalogToCamera, camera,
                                              catalog, drawImage )
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   Inputs
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   bCatalogToCamera    (3,3)    Transforms from the catalog frame to the 
                                camera frame
   camera              (1,1)    Camera data structure
                                .f       (1,1) Pixel conversion 
                                .wX      (1,1) Width of sensing element in X
                                .wY      (1,1) Width of sensing element in Y
                                .gain    (1,1) Camera gain
                                .noise   (1,1) Include the noise model
                                .sigmaXY (1,1) Position noise
                                .sigmaI  (1,1) Intensity noise
                                .sigmaFS (1,1) False star noise
                                .fSAtEnd (1,1) 1 if false stars are at the end of the measurements
   catalog             (1,1)    Star catalog data structure or name
   drawImage           (:)      If entered will draw a star image

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   Outputs
   -------
   starMeasurement     (1,1)    Data structure
                                .pixelLocation  (2,m) Coordinates of centroid [x;y]
                                .pixelIntensity (1,m) Intensity of each object
                                .star           (1,:)
   camera              (1,1)    Camera data structure
                                .fScale  (1,1) Pixel conversion
                                .wX      (1,1) Width of sensing element in X
                                .wY      (1,1) Width of sensing element in Y
                                .gain    (1,1) Camera gain
                                .noise   (1,1) Include the noise model
                                .sigmaXY (1,1) Position noise
                                .sigmaI  (1,1) Intensity noise
                                .sigmaFS (1,1) False star noise

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