Calibration of long focal length cameras in close range photogrammetry

Abstract

AbstractOne of the practical impediments to the adoption of long focal length lenses in close range photogrammetry is the difficulty in network exterior orientation and self‐calibration that can be encountered with the collinearity equation model when the camera field of view is smaller than around 10°. This paper reports on an investigation that examined two different avenues for improving the self‐calibration of long focal length cameras. The first is a re‐examination of the linearisation of the collinearity equations with additional calibration parameters, and especially determination of the coefficients in the design matrix corresponding to the interior orientation elements. The second is a new approach to the calculation of object space coordinates by employing an orthogonal projection model that can be formulated as a bundle adjustment with self‐calibration. Accuracy aspects of both approaches are discussed and test cases employing both zoom and macro lenses are presented.