ANALYTICAL IN-FLIGHT CALIBRATION

A general combined aerial triangulation and/or camera calibration program was used to determine camera focal length, symmetric radial lens distortion, and decentering lens distortion for a Wild RC 8 aerial mapping camera equipped with Aviogon Lens No. 15 UAg. 312. Three combinations of calibration parameters were utilized with four configurations of fixed ground control points using 14 and 21 photographs, respectively. Results are compared with each other and to the laboratory calibration of the lens. Calibrations with 21 photographs provide radial lens distortion curves which are fairly consistent and vary from the laboratory curve with discrepancies having RMSE of 2 micrometers. Tangential profiles are less consistent. Recovery of symmetric radial lens distortion parameters simultaneously with aerial triangulation is found to be feasible with photography having 60 per cent all-around overlap and with a fixed control point array of moderate density.