TILT COMPUTATION BY ANALYTICAL MEANS

摘要

Before an aerial photograph can be used for any purpose which requires extreme accuracy, it is necessary to determine the tilt of the photograph. This can be done graphically, mechanically, or by analytical computation. This report is concerned with the latter and the various methods by which analytical compu¬tations can be made.nAccurate results in an analytical computation depend on the availability of ground control and on close tolerances for the elements involved. Of all the tilt-computation methods analyzed, the most accurate results were obtained with completely analytical methods. Other methods serve the purpose if quick approxi¬mations are desired. Once the tilt of a photograph has been determined, measure¬ments made on the photograph can be corrected for its deviation from verticality.nIt is concluded that the most accurate tilt computation method should be made available to field organizations in the form of procedures which utilize electronic computers.