THE SPECIFIC CHARACTER OF LIMIT ERRORS IN CLOSE RANGE PHOTOGRAMMETRY

Closerange photogrammetry is to determine the shape and size of the object,instead of it's absolute position.Therefore,at first,any translation and rotation of the photogrammetric model of the object caused by whole geodesic,photographic and photogrammetric procedures in closerange photogrammetry could not be considered.However,it is necessary to analyze all the reasons which cause the deformations of the shape and size and to present their corresponding theories and equations.This situation,of course,is very different from the conventional topophotogrammetry.In this paper some specific characters of limit errors in closerange photogrammerty are presented in detail,including limit errors for calibration of interior elements for closerange cameras,the limit errors of relative and absolute orientations in closerange photogrammetric procedures,and the limit errors of control works in closerange photogrammetry.A theoretical equation of calibration accuracy for closerange camerais given.Relating to the three examples in this paper,their theoretical accuracy requirement of interior elements of camera change in the scope of ±（0.005～0.350） mm.This discussion permits us to reduce accuracy requirement in calibration for an object with small relief,but the camera platform is located in violent vibration environment.Another theoretical equation of relative RMS of base lines （ m S/S ） and the equation RMS of start direction are also presented.It is proved that the m S/S could be equal to the relative RMS of m Δ X / Δ X .It is also proved that the permitting RMS of start direction is much bigger than the traditionally used one.Some useful equations of limit errors in closerange photogrammetry are presented as well.Suggestions mentioned above are perhaps beneficial for increasing efficiency,for reducing production cost.