D. G. Tucker 49 
ducer) and financial assistance has been of the greatest value. The Fisheries 
Laboratories at Lowestoft and Aberdeen have also given help and stimulation. 
REFERENCES 
1. D.G. Tucker, "Signal—Noise Performance of Electroacoustic Strip Arrays,” Acustica, Vol. 8, 53 (1958). 
2. V.G. Welsby and D.G. Tucker, "Multiplicative Receiving Arrays,” J. Brit. Inst. Radio Engrs., Vol. 19, 
369 (1959). 
3: Ve 2 Wettam "Multiplicative Receiving Arrays: The Angular Resolution of Targets in a Sonar System 
with Electronic Scanning," J. Brit. Inst. Radio Engrs., Vol. 22, 5 (1961). 
4, V.G. Welsby, "A Note on a Possible Method of Improving the Directional Response of a Single-Fre- 
quency Multiplicative Receiver,” Electrical Eng. Dept., University of Birmingham, Memorandum No. 
89 (1961). 
5. A. Bloch, R.G. Medhurst, and S.D. Pool, “Superdirectivity,” Proc. Inst. Radio Engrs., Vol. 48, 1164 
(1960). (This paper gives very comprehensive bibliography of the subject.) 
6. D.G. Tucker, "Signal—Noise Performance of Super-Directive Arrays,” Acustica, Vol. 8, 112 (1958). 
7. W.E. Kock and J.L. Stone, "Space—Frequency Equivalence,” Proc. Inst. Radio Engrs., Vol. 46, 499 
(1958). 
8. V.G. Welsby, "Two-Element Aerial Array: Use of Multifrequency Carrier Waveform to Improve 
Directivity,” Electronic Technology, Vol. 38, 160 (1961). 
9. D.G. Tucker, "Space-Frequency Equivalence in Directional Arrays, with Special Reference to Super- 
Directivity and Reciprocity," Inst. Elect. Engrs. (London) Monograph 479 E (1961). 
10. V.G. Welsby, "Electronic Sector Scanning Arrays,” Electronic Technology, Vol. 39, 13 (1962). 
11. D.G. Tucker, “Arrays with Constant Beamwidth over a Wide Frequency Range,” Nature, Vol. 180, 496 
(1957). 
12, J.C. Morris and E, Hands, "Constant Beamwidth Arrays for Wide Frequency Bands," Acustica, Vol. 11, 
342 (1961). 
13. D.G. Tucker, V.G. Welsby, and R. Kendell, "Electronic Sector Scanning,” J. Brit. Inst. Radio Engrs., 
Vol. 18, 465 (1958). 
14. D.G. Tucker, V.G. Welsby, L. Kay, M.J. Tucker, A.R. Stubbs, and J.G. Henderson, "Underwater 
Echo-Ranging with Electronic Sector Scanning: Sea Trials on R.R.S. Discovery Il,” J. Brit. Inst. Radio 
Engrs., Vol. 19, 681 (1959). 
15. E.A. Howson and J.R. Dunn, "Directional Echo-Sounding,” J. Inst. Navigation (London), Vol. 14, 348 
(1961). 
16. B.S. McCarmey, "An Improved Electronic Sector-Scanning Sonar Receiver,” J. Brit. Inst. Radio Engrs., 
Vol. 21, 481 (1961). 
17. D.E.N. Davies, "A Fast Electronically Scanned Radar Receiving System," J. Brit. Inst. Radio Engrs., 
Vol. 21, 305 (1961). 
18. L. Kay, "A Plausible Explanation of the Bat’s Echo-Location Acuity,” Animal Behaviour, Vol. 10, 34 
(1962). 
19. L. Kay, "The Orientation of Bats and Men by Ultrasonic Echo-Location,” Brit. Communications and 
Electronics, Vol. 8, 582 (1961). 
20. D.G. Tucker, "Detection of Pulse Signals in Noise: Trace-to-Trace Correlation in Visual Displays,” 
J. Brit. Inst. Radio Engrs., Vol. 17, 319 (1957). 
21. D.C. Cooper and J. W.R. Griffiths, "Video Integration in Radar and Sonar Systems,” J. Brit. Inst. Radio 
Engrs., Vol. 21, 421 (1961). 
22. N.S. Nagaraja, "Intensity-Modulated Displays: Contrast Thresholds in the Presence of Noise," Elec- 
trical Eng. Dept., University of Birmingham, Memorandum No. 87 (1961). 
23. H.R. Blackwell, "Contrast Thresholds of the Human Eye,” J. Opt. Soc. Am., Vol. 36, 624 (1946). 
24. L. Kay, "Progress in Underwater Echo-Ranging: Recent Sea Trials in R.R.S. Discovery II,” Brit. Com- 
munications and Electronics, Vol. 8, 753 (1961). 
