ABSTRACT
However, in contrast to the situation with the two smaller format sizes, with large-format digital frame cameras-which are those generating individual frame images that are over 50 Megapixels in sizethe situation is very different. Development has to a large extent stagnated, although Fairchild Imaging has shown a prototype 100 Megapixel array at the ASPRS 2007 Annual Conference. However, the upper limit in terms of the arrays that are available commercially in production quantities is still the very expensive 85 Megapixel CCD area array produced by Fairchild Imaging, whose use is confined to certain U.S. military cameras. To overcome this limitation, the development of systems that can generate large-format digital frame images has gone in a totally different
4.1 INTRODUCTION
This chapter gives an overview of the airborne digital imaging sensors and systems that have been developed and have come into operational use during the period since the last ISPRS Congress was held in Istanbul in 2004. It expands on and updates the review of the systems that was presented at the ISPRS Commission I Symposium held in Marne-la-Vallee, France, in July 2006 (Petrie & Walker 2007). Overall the chapter is divided into two parts covering optical and radar imaging systems, respectively. In the case of the optical systems, they can be further divided into two main groups-digital frame cameras and digital line scanners. Thus, the developments in airborne digital imaging systems will be reviewed and discussed under three main headings:
(i) optical digital frame cameras; (ii) optical digital line scanners; and (iii) radar digital imaging systems.
