[8] Colvocoresses, Alden P. - Evaluation of the First Earth Resources Technology Satellite (ERTS-1) for Cartogra- 
phic Application. Commission I, International Society of Photogrammetry, Stockholm, Sweden, August 1974. 
[9] Bernstein, Ralph - Scene Correction (Precision Processing) of ERTS Sensor Data Using Digital Image Processing 
Techniques. NASA/GSFC Third ERTS Symposium, December 1973. 
[10] Colvocoresses, Alden P. - Space Oblique Mercator. Photogrammetric Engineering Vol. 40, n* 8, August 1974. 
[11] Skylab A, EREP Users Handbook. NASA Johnson Space Center, Houston, Texas, March 1971. 
[1 2] Welch, Roy - Skylab Image Evaluation. Memorandum for the Record (EC-1-Skylab) USGS EROS Cartography 
Coordinator, November 14, 1973. 
[13] Useful Applications of Earth-Oriented Satellites, Vol. 13, Geodesy-Cartography, National Academy of Sciences, 
Washington, D. C. 1969. 
h 4] Packard, Robert F. - International Legal and Political Aspects of Earth Resource Surveying by Satellite. American 
Institute of Aeronautics and Astronautics Paper 70-331, Annapolis, Maryland, March 1970. 
[1 5] Gordon, T.J. and Enzer, S. - Potential Institutional Arrangements of Organizations Involved in the Exploitation of 
Remotely Sensed Earth Resources Data. American Institute of Aeronautics and Astronautics. Paper 70-334, 
Annapolis, Maryland, March 1970. 
Abstract 
The possibility of map revision from space was first demonstrated by the addition of planimetric detail to the 
existing 1:250 000-scale map of Cape Kennedy using photographs made from the Gemini 5 and 7 spacecraft. Hasselblad 
photographs from Apollo 9 were used to prepare a photo image base for the 1:250 000-scale map of Phoenix, Arizona. 
The photographs disclosed corrections both in map content and geometric position. Imagery from the Multispectral 
Scanner on the ERTS-1 spacecraft is capable of providing positional data at scales compatible with 1:500 000 and 
1:250 000 maps. It is excellent for portraying major geographical and geological features. Many times new cultural 
features can be discerned, but in general the ground resolution is inadequate to serve as an independent source of map 
revision information. Skylab photographs have adequate resolution fox reproduction at scales as large as 1:50 000 and 
nearly all cultural information compatible with that scale can be interpreted from the photographs. As yet no topographic 
contour lines have been extracted from NASA space photography of the Earth. The Apollo lunar camera systems demons- 
trated the type of configuration which would be required for this application. Proposals have been made to NASA, but the 
best hope for such a system is now a payload to be launched and serviced by the Space Shuttle. 
Résumé 
La possibilité de réviserles cartes à l'aide de photos spatiales fut démontrée pour la première fois en ajoutant 
des détails planimétriques à la carte à 1:250.000 du Cap Kennedy avec des photos prises de Gemini 5 et 7. Des photos 
Hasselblad du vol Apollo 9 furent utilisées pour établir une photocarte à 1:250.000 de Phoenix, dans l'Arizona. Les 
photos révélaient des corrections à apporter aussi bien au contenu de la carte existante qu'à sa géométrie. Les images 
du Scanner Multispectral d'ERTS-1 sont capables d'apporter des données plänimétriques convenant à des cartes à des 
échelles de 1:500.000 ou 1:250.000. Elles sont excellentes pour mettre en évidence les grandes lignes de la géographie 
et de la géologie. Souvent de nouveaux détails concernant les cultures peuvent être discernés mais, en général, la réso- 
lution n'est pas suffisante pour que les photos puissent être utilisées pour la révision. Les photos de Skylab, par contre, 
ont une bonne résolution ; elles peuvent être agrandies à des échelles allant jusqu'à 1:50.000 et toutes les informations 
compatibles avec cette échelle peuvent être interprétées. Jusqu'à présent, aucune courbe de niveau n'a été obtenue à 
partir des photos spatiales de la NASA. La caméra lunaire d'Apollo a montré le type d'équipement qui serait nécessaire 
pour cette application. Des propositions ont été faites à la NASA, mais le meilleur espoir pour un tel système est main- 
tenant un engin qui serait lancé et récupéré par la navette spatiale. 
DISCUSSION 
H. YZERMANN - What is the accuracy obtainable in planimetric position from ERTS ? 
F.J. DOYLE - It depends upon how position is established : 
Referenced to latitude and longitude indicators on each frame : 1-8 km 
Referenced to ground control 
- best fit of image to UTM projection : 150-350 m 
- UTM grid fitted to single black and white image : 50-100 m 
- UTM grid fitted to black and white mosaic of several images : 100-150 m 
- UTM grid fitted to single multiband (colored) image : 150 m 
- UTM grid fitted to mosaic of several multiband (colored) images : 125-150 m 
J. CRUSET - I want to reserve the matter of an ISP support for the Friday morning meeting of the Council. However, 
I would like to say that some European Photogrammetrists told me that it is difficult to get ERTS-A photography of very 
good quality and that the best of the production goes to more or less commercial agencies. I would appreciate that Mr. 
Doyle clear the matter to make my opinion clearer before the council meets. : 
G. C. TEWINKEL - Should the ISP support the continuation of the ERTS system ? 
F.J. DOYLE - The ERTS data are primarily of value in developing countries where small scale maps and resource 
surveys are poor or non existent. They are difficult to justify in the United States or western Europe. NASA and the 
United States need encouragement to continue to operate a system which is of little direct benefit to them. A reso- 
lution by ISP council would be helpful in assuring the continuation of the system. 
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