FIXED-FRAME MULTIPLE-CAMERA SYSTEM FOR CLOSE-RANGE PHOTOGRAMMETRY

The fixed-frame multiple-camera system is described for measurement in the field of class-range photogrammetry, particularly in the field of bio-medicine. The design criterion is given for specimens ranging from 2-3 centimeters up to 2 meters. The laboratory consists of a geometrical arrangement of three MK-70 metric Hasselblad cameras. The framework provides a reference system and the frame is established from triangular shaped steel tubes pressed into a solid joint. The calibration of that system is described along side the methodology which is used. The methodology consists of determination of the coordinates of the camera stations by space resection and determination of the orientation elements of each camera station by analytical photogrammetry. These quantities after the calibration are regarded as fixed quantities. Subject has been determined by analytical space intersection which is the computation process in itself for the individual specimen. It has been found that the calibration using the negatives in transformation for reseau cameras ranges from three to six micrometers in the photo-coordinate system. The accuracy of the camera station coordinates determined by space resection is around 40-60 micrometers and the orientation elments also have been determined. The result of the space intersection from these fixed cameras is that the standard error is found to range from 0.8 of a millimeter to 0.1 of a millimeter, depending upon the camera configuration in general. These standard errors are regarded as satisfactory for most close-range photogrammetry. It has been found that the close-range photogrammetric laboratory is capable of providing fast and accurate three-dimensional measurement, particularly applied to the field of orthopaedics, and it was found that the laboratory has been utilized by various departments at the University of Washington, particularly the Department of Orthopaedics, Department of Orthodontics, and the School of Dentistry, besides the Department of Civil Engineering.