A NEW PHOTOGRAMMETRIC LAYOUT OF CAMERA STATIONS: A CASE STUDY

Abstract

This paper describes an easy and low cost photogrammetric method to determine the height of a point in relation to a reference plane. Such a method consists of an innovative geometric layout of the camera stations and specific algorithms. It is applicable to architectural surveying, in particular when the surface to be surveyed present a definitive geometry, with clearly identifiable defined points. The effectiveness of this method was verified through a case study carried out with the use of a digital camera and three dimensional targets. Two different pairs of images were obtained. One pair consists of images taken with a 35 mm and 19 mm focal length; the other one consists of images taken with a focal length of 35 mm and 28 mm. The accuracy obtained, calculated as RMS and errors on the points, is equivalent to 2,6 cm with a maximum error of 4.9 cm, for the configuration 35 -19 mm; equal to 3,4 cm, with a maximum error of 6,1 cm, for the configuration 35 - 28 mm. The advantages and disadvantages of the above method are then discusses. The system is Patent registered.