Geographical Aspects of Gemini Photography

190ASSOCIATION OF PACIFIC COAST GEOGRAPHERS Abstract Geographical Aspects of Gemini Photography Norman J. W Thrower University of California at Los Angeles Photographs of the earth taken from unmanned and manned space vehicles are becoming available in increasing numbers. Gemini flights IV through VII, for example, produced more tìian a thousand photographs of which about half were considered to be of geographical significance. These pictures were evaluated for die United States Army by a University of California at Los Angeles team consisting of Norman Thrower, Harold Haefner, John Estes, and Richard Watson. The purpose of the investigation was two-fold: (a) to provide interpretations of selected pictures and (b) to plot the geographical locations of all earth photographs deemed worthy of further study. The interpretations will be included with others from about twenty workers on a "space atlas" to be published in June 1966. The UCLA team had sole responsibility for the second part of the investigation which proved to be a challenging assignment. The pictures were taken more or less randomly by the astronauts with a handheld Hasselblad 500 camera having a Zeiss Planar lens and 80 millimeter focal length. For a majority of the pictures Eastman Kodak Ektachrome 70 millimeter film was used, but a few were taken with Kodak 70 millimeter Pan Atomic X Type 3400 film, producing near-infra-red images. The photographs cover, on the average, 10,000 square miles of earth surface each but this varies widely according to whether they were taken in apogee, 160 miles up or in perigee, 90 miles up. The area covered also varies enormously according to whether they are obliques or near vertical shots. All pictures in this series are confined within 40° north latitude and 30° south latitude, being limited by the orbits of the several flights. Within this range some areas are covered by several photos and many areas lack coverage altogether. Detailed locations were determined chiefly with the aid of small and intermediate scale maps and charts, a task which revealed the inadequacy of the world's cartographic coverage. Final plots were made on transparent plastic sheets overlaying 1:5,000,000 planning maps. The pictures taken from Gemini space craft, all originally in color, reveal broad patterns sometimes not evident in individual, conventional air photos or from ground inspection, e.g., certain geologic structures. On the other hand, some features which appear to be important on the earth are sometimes hardly discernible in the photo images, e.g., cities and transportation lines. Repeating patterns of cadastral survey systems indicated by fields dominated some pictures. To make this kind of photography more useful, three suggestions are proposed: 1.More direction of the coverage so that unphotographed areas traversed in past flights appear on the images. 2.Polar orbits to produce coverage of the mid-latitudes and polar regions as well as of the tropics and sub-tropics. 3.Synoptic pictures so that seasonal change and otìier variable phenomena can be better appreciated. ...