ose by highlighting the work of the many engineers who have figured prominently in the early conceptual development and implementation of spread- spectrum systems. 2.5 REFERENCES [1] R.A. Scholtz, "The origins of spread-spectrum communications," IEEE Trans. Commun., COM-30, pp. 822-854, May 1982 (Part I). [2] R. A. Scholtz, "Notes on spread-spectrum history," IEEE Trans. Commun., COM-31, pp. 82-84, Jan. 1983. The Historical Origins of Spread-Spectrum Communications [3] R. Price, "Further notes and anecdotes on spread-spectrum origins," IEEE Trans. Commun., COM-31, pp. 85-97, Jan. 1983. [4] E. V. Appleton and M.A.F. Barnett, "On some direct evidence for downward atmospheric reflection of electric rays," Proc. Roy. Soc. Ser. A. vol. 109, pp. 621- 641, Dec. 1, 1925. [5] D. G. C. Luck, Frequency Modulated Radar, New York: McGraw-Hill, 1949. [6] S.L. Johnston, "Radar ECCM history," Proc. NAECON, May 1980, pp. 1210- 1214. [7] G.R Johnson, "Jamming low power spread spectrum radar," Electron. Warfare, pp. 103-112, Sept.-Oct. 1977. [8] D.O. North, "An analysis of the factors which determine signal/noise discrim- ination in pulsed carrier systems," RCA Lab., Princeton, NJ. Rep. PTR-6C, June 25, 1943; see also Proc. IEEE, vol. 51, pp. 1015-1028, July 1963. J. H. Van Vleck and D. Middleton, "A theoretical comparison of the visual, aural, and meter reception of pulsed signals in the presence of noise," J. Appl. Phys., vol. 17, pp. 940-971, Nov. 1946. [10] P. M. Woodward, Probability and Information Theory, with Applications to Radar, New York: Pergamon, 1953. [11] F. E. Terman, "Administrative history of the Radio Research Laboratory," Radio Res. Lab., Harvard Univ., Cambridge, MA. Rep. 411-299, Mar. 21, 1946. [12] F.H. Lange, Correlation Techniques, Princeton, NJ: Van Nostrand, 1966. [13] G. Guanella, "Distance determining system," U.S. Patent 2 253 975, Aug. 26, 1941 (filed in U.S. May 27, 1939; in Switzerland Sept. 26, 1938). , "Direction finding system," U.S. Patent 2 166 991, July 25, 1939 (filed in U.S. Nov. 24, 1937; i