GEORGIA FROM SPACE- AN EXPLANATION OF THE NASA LANDSAT 1 SATELLITE IMAGE COLOR MOSAIC OF THE STATE OF GEORGIA Prepared in cooperation with the Georgia Department of Natural Resources, Geologic and Water Resources Division GEOLOGICAL SURVEY CIRCULAR 787 Georgia From Space- An Explanation of the NASA Landsat 1 Satellite Image Color Mosaic of the State of Georgia By Sam M. Pickering, Jr., and Michael W. Higgins GEOLOGICAL SURVEY CIRCULAR 787 Prepared in cooperation with the Georgia Department of Natural Resources, Geologic and Water Resources Division 1979 United States Department of the Interior CECIL D. ANDRUS, Secretary Geological Survey H. William Menard, Director Library of Congress Cataloging in Publication Data Pickering, Sam M. Georgia from space. (Geological Survey circular 787) "Prepared in cooperation with the Georgia Department of Natural Resources, Geologic and Water Resources Division." Bibliography: p. 1. Remote sensing-Georgia. 2. Georgia-Maps. I. Higgins, Michael W., joint author. II. Georgia. Geologic and Water Resources Division. III. Title. IV. Series: United States. Geological Survey. Circular 787. QE75.C5 no. 787 [G70.5.U6] 557.3'08s Free on application to Branch of Distribution, U.S. Geological Survey 1200 South Eads Street, Arlington, Va. 22202 PREFACE In its continuing program of monitoring the Nation's natural re­ sources and understanding the land we live on, the U.S. Geological Survey has now published six Landsat satellite color mosaics at scales suitable to show large areas such as entire States. More of these mosaics are planned, and with each new one the techniques and our ability to interpret the features seen on the mosa.ics are improving. We have chosen one mosaic, that of the State of Georgia, as an example of what can be seen and of some of the more general uses of these "pictures" from space. Both this circular and the mosaic were prepared as a joint effort of the U.S. Geological Survey and the Geologic and Water Resources Division of the Georgia Department of Natural Resources. iii CONTENTS Page Preface------------------------------------------------------------------ iii Introduction ------------------------------------------------------------- 1 VVhat is Landsat? -------------------------------------------------------- 1 VVhat do the colors on the Georgia mosaic mean? ---------------------------- 2 How was the mosaic made? ----------------------------------------------- 2 VVhat can be seen on the mosaic? ------------------------------------------ 2 Culture -------------------------------------------------------------- 2 Land use and land cover ---------------------------------------------- 2 Landforms ----------------------------------------------------------- 5 Geology ------------------------------------------------------------- 14 Summary ---------------------------------------------------------------- 21 References cited ---------------------------------------------------------- 21 Other maps and products to aid in understanding the Landsat mosaic ------- Inside of back cover ILLUSTRATIONS Page FIGURE 1. Band 5 Landsat mosaic of Georgia ----------------------------- 3 2. Generalized land-cover map of Georgia ------------------------- 4 3. Map showing landform divisions of Georgia -------------------- 6 4. Enlarged Landsat band 7 image of parts of northern Georgia, North Carolina, and Tennessee ---------------------------- 8 5. Map showing interpretation of figure 4 ------------------------- 9 6. Enlarged Landsat band 7 image, Fall Line -------------------- 10 7. Map showing interpretation of figure 6 ------------------------- 11 8. Enlarged band 7 image, northwestern Georgia ------------------ 12 9. Topographic map of the area of figure 8 ------------------------ 13 10. Block diagram illustrating general relation of ridges and valleys to anticlines and synclines -------------------------------- 14 11. Enlarged Landsat band 5 image, Pelham Escarpment ----------- 15 12. Enlarged Landsat band 7 image, Lake Seminole ---------------- 16 13. Explanation and location map for figure 12 --------------------- 17 14. Enlarged Landsat band 7 image, Okefenokee Swamp ------------ 18 15. Map showing interpretation of figure 14 ----------------------- 19 16. Landsat band 7 and band 5 images, marshes and estuaries ______ 20 v GEORGIA FROM SPACE- An Explanation of the NASA Landsat 1 Satellite Image Color Mosaic of the State o,f Georgia By Sam M. Pickering, Jr.,t and Michael W. Higgins INTRODUCTION our natural resources and their development Just a few years ago the prospect of a single until Landsat provided such an overview. view of an entire State the siz·e of Georgia This circular is keyed directly to the large s·eemed science fiction. With the launching of color mosaic of Georgia. To use the circular, the Landsat 1 (formerly called ERTS 1) sat­ refer to the indi,cated areas on the large mosaic. Addresses for obtaining the large mosaic, a telite into orbit ~around the Earth and the tech­ nological developments that have allowed its more detailed, interpretative space atlas of images to be successfully pieced together into a Georgia, and other maps that are helpful in mosaic, this "science fiction" ha:s become reality. understanding the State are listed inside the The new Landsat color mosaic of Georgia (U.S. back cover of this circular. Geological Survey, 1973-74) is an excellent ex­ ample of what we can now see from space. WHAT IS LANDSAT? Lands,at images and mosaics are valuable to The Lands'ait 1 satellite, launched by the Na­ g·eologists, soil scientists, foresters, ecolo·gists, tional Aeronautics and Space Administration lamd-use planners, mapmakers, and the general July 23, 1972, circles the Earth in an orbit that public. They allow us to see things too large and passes approximately over the North and South too widespread to be seen accurately and inex­ Poles. At an altitude of 570 miles, it orbits over pensively by other techniques. Until the 1600's any point on Earth once every 18 days. The in­ scientists could study only objects that could be struments on Landsat 1 ceased functioning seen with the naked eye. Then, in 1632, the January 6, 1978. While still functioning, instru­ microscope was invented, and a whole new ments aboard the satellite continuously scanned world of microscopic life was revealed. The the land and water beneath in four color bands ability to see dearly the very large features of and ,transmitted the signals back to receiving our Earth has given us similar opportunities. for stations on Earth. Thus Landsat 1 functioned new discoveries about our planet. somewhat like a detailed television broadcast This circular illustrates many of the uses and from space. At the present time (1978) Land­ details of the Georgia Landsat mosaic. It gives sats 2 and 3 are functioning. When the signals examples of how Landsat images can help peo­ reach Earth they are converted into black and ple understand the areas in which they live, white film images. Two of the four multispec­ work, and travel. One of the basic problems tral scanners on a satellite detect infrared radi­ today is keeping pace with the changes we make ation or light (bands 6 and 7). This type of on the face of the Earth. We build, harvest, light is not visible to the human eye, but shows mine, clear, reclaim, impound, and channelize differences in ground moisture and terrain. The without 1an overall view of what we are doing. remaining two scanners detect visible light We never before had a comprehensive look at (green, band 4, and red, band 5) and show pat­ 1 Georgia Department of Natural Resources. terns of vegetation and cultural development. 1 Individual black and white images or combina­ WHAT CAN BE SEEN ON THE MOSAIC? tions of the images in different color bands CULTURE show forests, cities, wetlands, cultivated fields, superhighways, and many other features. Each One of the first things most people want to image transmitted by the satellite covers. an know about a map such as the Geo·rgia mosaic is area of 13,500 square miles. Fourteen images where they live and where some of the places are needed to cover all of Georgia. and features they are familiar with are located. The Landsat mosaic of Georgia (fig. 1) shows many of the towns and ci·ties, reservoirs, and WHAT DO THE COLORS ON THE GEORGIA MOSAIC MEAN? major highways. One of the unusual cultural features is the circular woodland area in South The Georgia mosaic is a color combination of Carolina along the State line. This area sur­ red (band 5) and infrared (band 7) images. rounding the Savannah River Nuclear Plant is These combined images of each scene· were government-owned land that has not been tinted in shades of blue, black, and red to re­ farmed for many years and has. grown up in semble a color-infrared photograph. This meth­ heavy forest. Another prominent man-caused od shows cultural features and vegetation more feature on the mosaic is the white circular area clearly than a single black and white or a in Tennessee near the State line. This is an area natural-color image. Forest and vegetative where the forest was killed many decades ago cover show as red, and cleared land is white or by overcutting and smelter fumes at the Duck­ bluish. The reddest patterns on this mosaic are town-Copper Hill mining district. Although evergreen forest or winter pasture: the hard­ much reclamation work has been done recently, wood trees were leafless and summer crops had the area still shows as 80 square miles of barren been harvested when these late fall or winter