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Recognition of tree species on aerial photographs
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Vermessungskunde, III. (Sammlung Gi~schen Band 2162.) Walter Grossmann. Walter de Gruyter, Berlin, 1979~ 11th ed., 209 pp., DM 16.80. Although no major revisions appear in this new edition, it has undergone several minor changes. Trigonometric heighting, barometric heighting, tacheometry and engineering surveying are the subjects dealt with in this volume of the series Vermessungskunde. Chapter I discusses trigonometric heighting. With respect to the measuring of angles some additional remarks upon the S.I. systems are now given. Chapter 2, pertaining to barometric heighting, has hardly undergone any changes. The chapters dealing with tacheometry no longer describe the oldest tacheometers. Instead, the modern electronic tacheometers are mentioned. In later editions more attention should certainly be paid to the principles of these instruments and their use in geodetic practice. Chapter 6 is about engineering surveying. Major revisions appear in this chapter. The most modem instruments now in use are described. The contents of the book go beyond the elementary stage, but without getting too complicated. It should be considered an important aid to the student and a convenient guide for the professional. J. VAN MIERLO (Karlsruhe, F.R.G.)
Recognition of Tree Species on Aerial Photographs. L. Sayn-Wittgenstein. Canadian Forest Service, Ottawa, Ont., 1978, 97 pp. This is a manual that clearly and graphically demonstrates aspects of both the science and art of forest air-photo interpretation. Twenty-four pages cover interpretative aspects plus selected references. Seventy-three pages contain keys and illustra~,ed descriptions for identifying forty species of Canadian conifers and hardwoods, plus phenological data on some of them. Scales of 1:500--1:25,000 are considered, within which the author distinguishes four interpretability classes: 1:500, based on characteristics such as leaf and twig arrangements; 1:2500--1:3000, small and medium branches; 1:8000, where individual trees can be separated but crownshape is often not discernible; and 1:15,840, where assessment is usually in terms of tone, texture, site requirements and association. Panchromatic black and white is the commonest film-type; normal colour gives the fastest and most accurate interpretations. Hardwoods and eastern conifers are covered in separate keys and additional conifers are described individual]Ly.
201
Descriptions highlight ecological relationships and species' characteristics such as shape, branching habit, foliage, and shadow-pattern within crowns, plus the shape and density of shadows on the ground visible at large scales. Most conifers have a definite and characteristic crownshape; hardwoods do not. However, identification of young trees is usually difficult. Leaf formation and flowering can provide significant clues, especially on spring photographs of hardwoods. Nevertheless, summer photography is the commonest type because of weather and the constancy of species' appearance Fall photography provides distinction between some hardwoods but wide variability in leaf colours and fall is a problem. Winter photography, although rarely used, sometimes shows useful shadow details on snow. Illustrations include vertical stereograms, sometimes at two scales, but with a bias to larger scales; plan and profile sketches of crownshapes; and photographic profiles. Loss of quality in the screened reproductions is co~siderable but this does not detract significantly from the overall high standard and value of the report. In any case, the author thoughtfully provides details to enable serious users to obtain continuous-tone prints of high quality. The report is therefore recommended highly for practitioners plus tutors and students in forest photo-interpretation. RAYMOND D. SPENCER (Middle Park, Vic.)
Maps for America -- Cartographic Products o f the U.S. Geological Survey and Others: A Centennial Volume 1879--1979. Morris M. Thompson, U.S. Geological Survey, Reston, Va., 1979, 265 pp. The United States Geological Survey (USGS), which has responsibility for the U.S. National Mapping Program, observed its 100th anniversary in 1979. It is entirely fitting that such a milestone should be commemorated by the publication of this impressive volume. It is a monument to a century of important USGS mapping support to the nation. The author, a long-time USGS cartographer, is well known for his own contributions to the present state-of-the-art of U.S. cartography. His book is distinguished by his affection for the subject. It is not a textbook of cartography, since it does not contain details of how maps are made. Instead, it rather successfully explains the meaning of the map content: the colors, images, lines, symbols, captions and notes. After a brief discussion of the history of U.S. surveying and mapping programs, the book introduces the U.S. National Mapping Program, which then becomes the principal theme. There is an interesting and well-illustrated chapter on space age mapping and some guarded predictions about future trends in cartography.
Vermessungskunde, III. (Sammlung Gi~schen Band 2162.) Walter Grossmann. Walter de Gruyter, Berlin, 1979~ 11th ed., 209 pp., DM 16.80. Although no major revisions appear in this new edition, it has undergone several minor changes. Trigonometric heighting, barometric heighting, tacheometry and engineering surveying are the subjects dealt with in this volume of the series Vermessungskunde. Chapter I discusses trigonometric heighting. With respect to the measuring of angles some additional remarks upon the S.I. systems are now given. Chapter 2, pertaining to barometric heighting, has hardly undergone any changes. The chapters dealing with tacheometry no longer describe the oldest tacheometers. Instead, the modern electronic tacheometers are mentioned. In later editions more attention should certainly be paid to the principles of these instruments and their use in geodetic practice. Chapter 6 is about engineering surveying. Major revisions appear in this chapter. The most modem instruments now in use are described. The contents of the book go beyond the elementary stage, but without getting too complicated. It should be considered an important aid to the student and a convenient guide for the professional. J. VAN MIERLO (Karlsruhe, F.R.G.)
Recognition of Tree Species on Aerial Photographs. L. Sayn-Wittgenstein. Canadian Forest Service, Ottawa, Ont., 1978, 97 pp. This is a manual that clearly and graphically demonstrates aspects of both the science and art of forest air-photo interpretation. Twenty-four pages cover interpretative aspects plus selected references. Seventy-three pages contain keys and illustra~,ed descriptions for identifying forty species of Canadian conifers and hardwoods, plus phenological data on some of them. Scales of 1:500--1:25,000 are considered, within which the author distinguishes four interpretability classes: 1:500, based on characteristics such as leaf and twig arrangements; 1:2500--1:3000, small and medium branches; 1:8000, where individual trees can be separated but crownshape is often not discernible; and 1:15,840, where assessment is usually in terms of tone, texture, site requirements and association. Panchromatic black and white is the commonest film-type; normal colour gives the fastest and most accurate interpretations. Hardwoods and eastern conifers are covered in separate keys and additional conifers are described individual]Ly.
201
Descriptions highlight ecological relationships and species' characteristics such as shape, branching habit, foliage, and shadow-pattern within crowns, plus the shape and density of shadows on the ground visible at large scales. Most conifers have a definite and characteristic crownshape; hardwoods do not. However, identification of young trees is usually difficult. Leaf formation and flowering can provide significant clues, especially on spring photographs of hardwoods. Nevertheless, summer photography is the commonest type because of weather and the constancy of species' appearance Fall photography provides distinction between some hardwoods but wide variability in leaf colours and fall is a problem. Winter photography, although rarely used, sometimes shows useful shadow details on snow. Illustrations include vertical stereograms, sometimes at two scales, but with a bias to larger scales; plan and profile sketches of crownshapes; and photographic profiles. Loss of quality in the screened reproductions is co~siderable but this does not detract significantly from the overall high standard and value of the report. In any case, the author thoughtfully provides details to enable serious users to obtain continuous-tone prints of high quality. The report is therefore recommended highly for practitioners plus tutors and students in forest photo-interpretation. RAYMOND D. SPENCER (Middle Park, Vic.)
Maps for America -- Cartographic Products o f the U.S. Geological Survey and Others: A Centennial Volume 1879--1979. Morris M. Thompson, U.S. Geological Survey, Reston, Va., 1979, 265 pp. The United States Geological Survey (USGS), which has responsibility for the U.S. National Mapping Program, observed its 100th anniversary in 1979. It is entirely fitting that such a milestone should be commemorated by the publication of this impressive volume. It is a monument to a century of important USGS mapping support to the nation. The author, a long-time USGS cartographer, is well known for his own contributions to the present state-of-the-art of U.S. cartography. His book is distinguished by his affection for the subject. It is not a textbook of cartography, since it does not contain details of how maps are made. Instead, it rather successfully explains the meaning of the map content: the colors, images, lines, symbols, captions and notes. After a brief discussion of the history of U.S. surveying and mapping programs, the book introduces the U.S. National Mapping Program, which then becomes the principal theme. There is an interesting and well-illustrated chapter on space age mapping and some guarded predictions about future trends in cartography.