This chapter presents mathematical fundamentals which are essential for a deeper understanding of close-range photogrammetry. After defining some common coordinate systems, the most important plane and spatial coordinate transformations are summarized. An introduction to homogeneous coordinates and graphical projections then follows and the chapter concludes with the basic theory of leastsquares adjustment.
Photogrammetric imaging technologies for close-range measurement purposes impact upon all elements in the measurement process, from the preparation of the measuring object prior to imaging, through image acquisition, to subsequent analysis of the image content. Following an introduction to the physics behind optical imaging, issues including distortion, resolution and sampling theory are discussed. Common photogrammetric imaging concepts are briefly presented such as online and offline approaches and imaging configurations. The key part of this chapter deals with the geometric analysis defining the camera as a measuring tool, i.e. photogrammetric camera modelling, parameters of interior orientation and correction of imaging errors. Current components and sensor technologies for 2D image acquisition are then reviewed in the sections which follow. From there, discussion moves to signalization (targeting), light projection and illumination, which are critical in achieving photogrammetric accuracy.
This chapter considers photogrammetric projects from the perspective of planning, accuracy and optimization. In most practical cases the required measurement accuracy in object space is critical to the design and configuration of a measurement process. Generally speaking, the accuracy to which features of interest can be coordinated is closely connected with costs and commercial viability of a system solution. However, there are a number of additional planning criteria to be taken into consideration. These are summarized in Section 7.1.1. The planning of a photogrammetric configuration and strategy is a complex process requiring due regard for a wide range of issues. Here the question of camera calibration plays a particular role and requires careful consideration, depending on the selected imaging technology and required accuracy. The image measurement network must be so configured that constraints imposed by object complexity, the specified accuracy, camera calibration, technical effort required and cost from commission through operation are all taken fully into account.
The techniques of close-range photogrammetry provide universal methods and approaches to the geometric measurement of almost any kind of object. As a result, there are a wide range of potential application areas. The following example applications represent only a small selection from the entire spectrum of possibilities. They are restricted to sample images, results and key technical specifications. Examples processed using film cameras can, conveniently and without restriction, be implemented using current digital cameras. References to examples can be found in Section 9.8.