A surveying apparatus and method for surveying and tracking a moving object is disclosed to improve the tracking so that a moving object may be tracked reliably and automatically. The surveying apparatus comprises an optical arrangement to sight an object, and a tracking unit to track the sighted object....http://www.google.ca/patents/US8149388?utm_source=gb-gplus-sharePatent US8149388 - Surveying apparatus for tracking and surveying an object
