Introduction to Small-Format Aerial Photography

Chapter 1 Introduction to Small-Format Aerial Photography resources (Warner et al., 1996; Bauer et al., 1997). The Small is beautiful. field is ripe with experimentation and innovation of E. Schumacher 1973, quoted by Mack (2007). equipment and techniques applied to diverse situations. In the past, most aerial photography was conducted from 1.1. OVERVIEW manned platforms, as the presence of a human photographer looking through the camera viewfinder was thought to People have acquired aerial photographs ever since the be essential for acquiring useful imagery. For example, means have existed to lift cameras above the Earth’s Henrard developed an aerial camera in the 1930s, and he surface, beginning in the mid-19th century. Human desire to photographed Paris from small aircrafts for the next four see the Earth ‘‘as the birds do’’ is strong for many practical decades compiling a remarkable aerial survey of the city and aesthetic reasons. From rather limited use in the 19th (Cohen, 2006). century, the scope and technical means of aerial photog- This is still true for many missions and applications raphy expanded throughout the 20th century. The technique today. Perhaps the most famous modern aerial artist- is now utilized for all manners of earth-resource applica- photographer, Y. Arthus-Bertrand, produced his Earth from tions from small and simple to large and sophisticated. above masterpiece by simply flying in a helicopter using Aerial photographs are taken normally from manned hand-held cameras (Arthus-Bertrand, 2002). Likewise, airplanes or helicopters, but many other platforms may be G. Gerster has spent a lifetime acquiring superb photo- used, including balloons, tethered blimps, drones, gliders, graphs of archaeological ruins and natural landscapes rockets, model airplanes, kites, and even birds (Tielkes, throughout the world from the open door of a small airplane 2003). Recent innovations for cameras and platforms have or helicopter (Gerster, 2004). led to new scientific, commercial, and artistic possibilities The most widely available and commonly utilized for acquiring dramatic aerial photographs (Fig. 1-1). manned platform nowadays is the conventional fixed-wing The emphasis of this book is small-format aerial small airplane, employed by many small-format aerial photography (SFAP) utilizing 35- and 70-mm film cameras photographers (Caulfield, 1987). Among many recent as well as compact digital and video cameras. In general examples, archaeological sites were documented for many terms, such cameras are typically designed for hand-held years by O. Braasch in Germany (Braasch and Planck, use, in other words of such size and weight that amateur or 2005), and by Eriksen and Olesen in northwestern professional photographers normally hold the camera in one Denmark (2002). In central Europe, Markowski (1993) or both hands while taking pictures. Such cameras may be adopted this approach for aerial views of Polish castles. employed from manned or unmanned platforms ranging in Ba´rta and Barta (2006), a father and son team, produced height from just 10s of meters above the ground to 100s of stunning pictures of landscapes, villages and urban scenes kilometers into space. Platforms may be as simple as in Slovakia. a fiberglass rod to lift up a point-and-shoot camera, as In the United States, Hamblin (2004) focused on pano- purpose-designed as a remotely controlled blimp for vertical ramic images of geologic scenery in Utah, and D. Maisel image acquisition, or as complex as the International Space has sought out provocative images of strip mines, dry lake Station with its specially designed nadir window dedicated to beds, and other unusual landscape patterns in the western Earth observation (Fig. 1-2). United States (Gambino, 2008). In one of the most unusual SFAP became a distinct niche within remote sensing manned vehicles, C. Feil pilots a small autogyro for land- during the 1990s and has been employed in recent years scape photography in New York and New England of the for documenting all manners of natural and human United States (Feil and Rose, 2005). An ultralight aircraft is Small-Format Aerial Photography Copyright Ó 2010 Elsevier B.V. All rights reserved. 1 2 Small-Format Aerial Photography FIGURE 1.1 Vertical view of abandoned agricultural land dissected by erosion channels near Freila, Province of Granada (Spain) during a photographic survey taken with a hot-air blimp (left of center) at low flying heights. The blimp is navigated by tether lines from the ground; camera functions are remotely controlled. Its picture was taken with a compact digital camera in continuous shooting mode from an autopiloted model airplane following Google-Earth-digitized flight lines at w200 m height. The takeoff pad at right is 12 Â 8 m in size. Photo by C. Claussen, M. Niesen, and JBR, September 2008. N. Chorier’s magnificent pictures of India (Chorier and Mehta, 2007). Such imagery has large scale and excep- tionally high spatial resolution that depict ground features in surprising detail from vantage points difficult to achieve by other means (Fig. 1-3). These photographic views bridge the gap between ground observations and conventional airphotos or satellite images. 1.2. BRIEF HISTORY Since ancient times, people have yearned to see the landscape as the birds do, and artists have depicted scenes of the Earth as they imagined from above. Early maps of major cities often were presented as bird’s-eye views, showing streets, buildings, and indeed people from a perspective that FIGURE 1.2 Artist’s rendition of the International Space Station only could be imagined by the artist. Good examples can be following installation of its nadir-viewing optical-quality window in found in Frans Hogenberg’s Civitates Orbis Terrarum 2001. Arrow (^) indicates position of nadir window. Image adapted from (Cologne, 1572–1617). Seventeenth-century artists such as Johnson Space Center Office of Earth Sciences (Image JSC2001e00360) Wenceslaus Hollar engraved remarkable urban panoramas <http://visibleearth.nasa.gov/>. that showed cities from an oblique bird’s-eye view. The visual impact of such images is remarkably close to that of utilized for archaeological and landscape scenes in the aerial photographs. southwestern United States by A. Heisey (Heisey and George Catlin was another leading practitioner of Kawano, 2001; Heisey, 2007). aerial vantages in the early 1800s (Fig. 1-4). Catlin Unmanned, tethered or remotely flown platforms are adopted a documentary style of painting in order to coming into increasingly widespread use nowadays. This represent natural and human conditions in realistic terms. book highlights such unmanned systems for low-height By sheer force of their imagination and their technical SFAP, including kites, blimps, and drones. Representative mastery, Catlin and previous artists simulated the act of recent kite aerial photography, for example, includes taking images from the air. It was not until the mid-1800s, C. Wilson’s (2006) beautiful views of Wisconsin in the however, that two innovations combined, namely manned United States, E. Tielkes’s (2003) work in Africa, and flight and photochemical imagery, to make true aerial Chapter j 1 Introduction to Small-Format Aerial Photography 3 FIGURE 1.3 Closeup vertical view of elephant seals on the beach at Point Piedras, California, United States. These juvenile seals are w2 to 2.5 m long, and most are sleeping on a bank of seaweed. People were not allowed to approach the seals on the ground, but the seals were not aware of the photographic activity overhead. The spatial detail depicted in such images is extraordinary; individual pebbles are clearly visible on the beach. Kite aerial photograph taken with a compact digital camera. Photo by SWA and JSA, November 2006. 1.2.1. Nineteenth Century Louis-Jacques-Mande´ Daguerre invented photography based on silver-coated copper plates in the 1830s, and this process was published by the French government in 1839 (Romer, 2007). The earliest known attempt to take aerial photographs was made by Colonel Aime´ Laussedat of the French Army Corps of Engineers (Wolf and Dewitt, 2000). In 1849, he experimented with kites and balloons, but was unsuccessful. The first documented aerial photograph was taken from a balloon in 1858 by Gaspard Fe´lix Tournachon, later known as ‘‘Nadar’’ (Colwell, 1997). He ascended in a tethered balloon to a height of several hundred meters and photographed the village of Petit Biceˆtre, France. Later that same year, Laussedat again tried to use a glass-plate camera lifted by several kites (Colwell, 1997), but it is uncertain if he was successful. The oldest surviving airphoto was taken by S.A. King and J.W. Black from a balloon in 1860 over Boston, Massachusetts (Jensen, 2007). Hydrogen-filled balloons were utilized for observations of enemy positions during the American Civil War (1861– 1865); photographs reputedly were taken, although none have survived (Jensen, 2007). Meanwhile, Tournachon continued his experiments with balloons and aerial Bird’s-eye view of Niagara Falls, Canada, and the United FIGURE 1.4 photography in France with limited success. In 1887, States. George Catlin, 1827, gouache, w45 Â 39 cm. Adapted from Dippie et al. (2002, p. 36). a German forester obtained airphotos from a balloon for the purpose of identifying and measuring stands of forest trees photography possible. Since then, photography and flight (Colwell, 1997). have developed in myriad ways leading to many manned Already in the 1850s, stereophotography was practiced, and unmanned methods for observing the Earth from and new types of glass led to modern anastigmatic camera above (Fig. 1-5). lenses by 1890 (Zahorcak, 2007). Experimental color 4 Small-Format Aerial Photography FIGURE 1.5 Schematic illustration of the ‘‘multi’’ approach for remote sensing of the Earth’s surface from above. Multiple types of platforms and instruments operating at multiple heights. SFAP as emphasized in this book deals primarily with the ultra-low height range of observations.

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