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C00002 00002	{≥G⊂CαLOCUS SOLVINGλ30P95JUFA}
C00004 00003	⊂9.4	Sun Locus Solving: A Simple Solar Emphemeris.⊃
C00007 00004	⊂9.5	Related and Future Locus Solving Work.⊃
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{≥G;⊂C;αLOCUS SOLVING;λ30;P95;JUFA}
⊂9.3	Object Locus Solving: Silhouette Cone Intersection.⊃

	After the  camera  location, orientation  and projection  are
known; 3-D object  models can  be constructed.   The  silhouette cone
intersection method is a conceptually simple form of  wide angle,
stereo recontruction.  The idea arose out of an  original intention to
do "blob" oriented visual model aquistion, however a 2-D blob came to
be represented  by a silhouette  polygon and  a 3-D blob  consquently
came to  be represented by  a polyhedron. The  present implementation
requires a very favorably arranged viewing environment (white objects
on  dark backgrounds  or  vise versa);  application  to more  natural
situations might be  possible if the necessary hardware (or software)
were  available  for   extracting  depth   discontinuities  by   bulk
correlation. Furthermore, the restriction to turntable rotation is for
the sake  of easy camera solving; this restriction could be lifted by
providing stronger feature tracking for camera calibration.
⊂9.4	Sun Locus Solving: A Simple Solar Emphemeris.⊃
	
	The location of the  sun is useful to a  robot vehicle vision
system  both for sophisticated scene  intrepretation and for avoiding
the  blunder  of  burning  holes  in  the  television   vidicon.  The
approximate position  of the sun in  the sky is readily computed from
the time, date, latitude and longitude using circular approximations.

{λ10;JAF3;}
PROCEDURE SUNLOCUS (REAL DAY,TIME,LAT,LONG; REFERENCE REAL SUNAZM,SUNALT);
BEGIN
	REAL RHO,PHI,TMP,ECLIPTIC;
COMMENT POSITION OF THE SUN ON THE ECLIPTIC IN THE CELESTIAL SPHERE;
	ECLIPTIC←	((23+27/60)*PI);
	RHO	←	2*PI*DAY/365.25
	EAST	←	SIN(RHO)*COS(ECLIPTIC);
	NORTH	←	SIN(RHO)*SIN(ECLIPTIC);
	ZENITH	←	COS(RHO);
COMMENT LOCAL MERIDIAN OF LONGITUDE;
COMMENT LOCAL SOLAR TIME = (24 HOUR PACIFIC STANDARD TIME - 8 MINUTES 44 SECONDS);
	PHI	←	PI*(1-TIME/12) - ATAN2(EAST,ZENITH);
	TMP	←	ZENTITH*COS(PHI) - SIN(PHI)*EAST;
	EAST	←	EAST*COS(PHI) + SIN(PHI)*ZENITH;
	ZENITH	←	TMP;
COMMENT ROTATE CLOCKWISE IN THE NORTH/ZENITH PLANE TO LOCAL LATITUDE;
	TMP	←	COS(LAT)*ZENITH + SIN(LAT)*NORTH;
	NORTH	←	COS(LAT)*NORTH  - SIN(LAT)*ZENITH;
	ZENITH	←	TMP;
CONVERT TO ANGULAR MEASURES;
	SUNAZM	←	ATAN2(NORTH,EAST);
	SUNALT	←	PI/2 - AOCS(ZENTIH);
END "SUNLOCUS";
{λ30;JUFA;}
⊂9.5	Related and Future Locus Solving Work.⊃

	Although the  bulk of this  chapter concerned  camera solving
using one  view of three points the  multi view camera calibration is
probably more important to continous image processing but I have very
little to contribute at this time  to the existing collection of hill
climbing error minimizing methods.

I  have always disliked  the multi dimensional  hill climber approach
and have  sought  a  more geometric  and  intuitive solution  to  the
problem;  so far  I  have only  turned  up a  hill  climber in  fewer
dimensions (three  degrees of  freedom)  involving six  tonged  forks
which are  rotated about  iron circle  in two  planes Orbiting  forks
sweep out  families of hyperbolic sheets which  leaves one with a set
of contrainted second order  equations in one parameter, which  might
yet have a closed form anayltic solution.