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18. 
19. 
20. 
21. 
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23. 
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26. 
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Scott, F., Scott, R. M., and Shack, R. V., 1963, "The Use of Edge 
Gradients in Determining Modulation Transfer Functions," Photo- 
graphic Science and Engineering, Vol. 7, No. 6, pp. 345-349. 
  
  
Trinder, J. C., 1973, "Point Precision, Spread Functions and MIF," 
Photogrammetric Engineering, Vol. 39, No. 8, pp- 863-874. 
  
Welch, R., 1971, "Modulation Transfer Functions," Photogrammetric 
Engineering, Vol. 37, No. 3, pp. 247-259. 
  
Welch, R., 1972a, "The Prediction of Resolving Power of Air and 
Space Photographic Systems," Image Technology, Vol. 14, No.5, 
pp. 25-32. 
Welch, R., 1972b, "Photomap Image Quality," The Cartographic 
Journal, Vol. 9, No. 2, pp. 87-92. 
Welch, R., 1974a, "MTF Analysis Techniques Applied to ERTS-1 and 
Skylab-2 Imagery," Image Assessment and Specification, Proceedings 
of the Society of Photo-Optical Instrumentation Engineers, Vol. 
46, pp. 258-262. 
Welch, R., 1974b, "Skylab-2 Photo Evaluation," Photogrammetric 
Engineering, Vol. 40, No. 10, pp. 1221-1224. 
Welch, R., 1975, "Photogrammetric Image Evaluation Techniques," 
Photogrammetria, Vol. 31, No. 5, pp. 161-190. 
  
Welch, R. and Halliday, J., 1973, "Imaging Characteristics of 
Photogrammetric Camera Systems,’ Photogrammetria, Vol. 29, pp. 1-43. 
  
Welch, R. and Halliday, J., 1975, "Image Quality Controls for 
Aerial Photography," Photogrammetric Record, Vol. 8. No. 45, 
pp. 317-325. 
  
Optical Engineering 13, 1974, pp 6209-211, Sep/Oct issue. 
Image Assessment and Specification, SPIE Seminar Proceedings, Vol. 
46, 1974. (SPIE, Palos Verdes Estates, California) 
Rosenbruch, K.J., "Trends in the Development of OTF-Measuring 
Equipments." SPIE Seminar Proceedings 46, 1974. 
Schowengerdt, R. A., Antos, R. L., and Slater, P.N., "Measurement 
of the ERTS-1 Multispectral Scanner OTF from Operational Imagery," 
pp 247-257. 
Welch, R., "MTF Analysis Techniques Applied to ERTS-1 and Skylab-2 
Imagery," pp 258-263.