System of Units, and Selection of the Decimal Multiples and Submultiples. Std 315 contains sections on antennas (which permit.s incorporat,ion of antenna polarization and steerability in a set of int,ernat.ionally recommended symbols) and waveguides, again internationally recommended. At present, committees in GAP are engaged in the following standards projects. A group is working on definitions of t.erms and test procedures relating to antenna,s in physical media. IEEE Std 145-1969, is being revised and updated. Under the sponsorship of the Wave Propagation Standards Committee, t.here are t.ask groups on propagation curves and prediction techniques, ionogram st,andardization, radio meteorology measurements, informatkn storage and retrieval for wave ProDagation, methods of measuring ground conductivit.y, a.nd microwave field st,rength measurements. To summarize, the documents cit,ed are of great utility to anyone enga.ged in testing, measurement, generation of specifications, or report writing and nil1 also provide a practical introduction to novices in antenna and propagation technology. First-Order Theory and Analysis of MF/HF/VHF Scatter from the Sea Absfmci-Scatter from the sea near grazing from M F through VHF is analyzed in this paper. Results based on the compensation theorem show that the dependence upon the grazing angles, as well as upon frequency, range, and the effective surface impedance, can be removed for vertical polarization as the familiar "Norton attenuation factors." Time variation of the surface is included, and results are derived for both the average received power and its spectral density. The fist-order dispersion relationship for graviv waves is used to show that the received spectrum from a patch of sea consists of two discrete Doppler shifts above and below the carrier, predictable from simple Bragg =action considerations. Using the Phillips wind-wave model as an upper limit for wave heights, estimates for u0 (radar cross section per unit area) of-17 dB are obtained near grazing. Both the magnitude of urno predicted from theory and the nature of the received spectrum are compared with measurements, and the agreement supports the theory on both counts. Finally, the use of MF/Ell? radars for measuring sea state is suggested and discussed.