Patent ID: 7589302

Claim:
A tracking system for tracking a celestial object for use in a location where the object passes through or near the zenith, comprising: a first axis for tracking the object, said first axis being offset from vertical; and a second axis for tracking the object, said second axis being substantially perpendicular to said first axis; wherein said first axis is offset from the vertical by an angle that removes an upward projection of said first axis from the apparent path of the object by an amount that renders an overall speed of said tracking system sufficient to maintain tracking of the object as the object passes through or near the zenith; wherein said angle has a component of at least A in a direction away from the equator, where: A = 23.5 ⁢ ° -  λ  + 45 ⁢ ( degree ⁢ s 2 ⁢ / ⁢ min ) 2 ⁢ ⁢ σ and where λ is the latitude of said tracking system and σ is the maximum angular velocity with which said tracking system can evolve said first axis in degrees per minute.