Search Results

The search returned 1,243 publication(s) on its.ntia.gov.

John J. Tary, T. Layne Livingston, and Donald R. Macken, “Application of multiplex channels on FM and TV broadcast stations to educational needs,” Technical Memorandum ERL TM ITS 128, January 1968

Most radio systems are designed with bandwidths that are wider than necessary, resulting in wasteful use of the radio spectrum and failure to fully utilize the system capacity. This report reviews efforts to multiplex additional communications channe...

Lowell H. Tveten, Robert D. Hunsucker, W. J. Surtees, and Leslie A. Berry, “Backscatter studies and 3 -D ray tracing final report,” Technical Memorandum ERL TM ITS 136, January 1968

Feasibility of using backscatter to assess the accuracy of simultaneous direction-of-arrival measurements indicates poorer direction-of-arrival readings when backscatter shows travelling ionospheric disturbances. (Applies to simple mode paths.) The t...

Lowell H. Tveten, Leslie A. Berry, Robert D. Hunsucker, and W. J. Surtees, “Backscatter Studies and 3 -D Ray-Tracing, Final Report Sept. 1967 -Dec. 1968, Tech. Memo. ERLTMC-ITS 175 (References: Qtrly repts Jan-Mar 1967, IERTM-ITSA 59; Oct. -Dec. 1967, ERLTM-ITS 127; Jan-Mar 1968, ERLTMC-ITS 142; Apr-Jun 1968,” Technical Memorandum ERL TMC ITS 175, January 1968

Ionospheric irregularities represent departures from the ambient of up to 50% in electron density. Periods of high magnetic activity exhibit direction-of-arrival deviations which are more frequent and of greater magnitude than quiet periods. Mills T ...

M. E. Johnson, Martin J. Miles, Paul L. McQuate, and Albrecht P. Barsis, “Tabulations of VHF Propagation Data Obtained Over Irregular Terrain at 20, 50, and 100 MHz Part 3: Ohio Data,” Technical Report IER 38-ITSA 38-3, December 1967

This report contains tabulations of transmission loss data resulting from propagation experiments at 20, 50, and 100 MHz conducted over irregular and partly wooded terrain in northeastern Ohio. Raw data from measurements described in this report is ...

Laurance G. Hause and Roger K. Salaman, “Communications Task ­a study of propagation and noise for advanced ICBM weapons systems, Vol. IV Test Plan (Appendix 6),” Technical Memorandum RL TM ITS 110, December 1967

This final report contains the results of an extensive study program, the development of a method for evaluating candidate communication systems, and the design of a test plan to supplement the information from the study program and provide realistic...

Richard E. Skerjanec, “An Interim Report on Nanosecond Pulse Propagation over Line-of-Sight Paths,” Technical Memorandum IER TM ITSA 92, October 1967

During October and November 1966, propagation measurements were made on two-line-of-sight paths between the islands of Maui and Hawaii, utilizing paths of a nominal 1-ns width at a carrier frequency of approxi­mately 9 GHz. Prime objective was to de...

Harold T. Dougherty, “Microwave Fading with Airborne Terminals,” Technical Report IER 58 ITSA 55, October 1967

After a brief description of the significance of the radio refractive index and its variation in the atmosphere, a brief catalogue of fading mechanisms is presented. Attention is directed to the variety of fading mechanisms that are pertinent for th...

M. E. Johnson, Martin J. Miles, Paul L. McQuate, and Albrecht P. Barsis, “Tabulations of VHF Propagation Data Obtained Over Irregular Terrain at 20, 50, and 100 MHz Part 2: Colorado Mountain Data,” Technical Report IER 38-ITSA 38-2, August 1967

This report contains tabulations of transmission loss data resulting from propagation experiments at 20, 50, and 100 MHz conducted over irregular terrain in the Colorado Mountains primarily east of the Continental Divide. Raw data from measurements ...

Margo Leftin, Sidney Maurice Ostrow, and C. Preston, “Numerical maps of monthly median h’F, F2 for solar cycle minimum and maximum,” Technical Memorandum IER TM ITSA 69, July 1967

Numerical maps of h IF, F2 were prepared for all 12 months of 1954, a solar cycle minimum year, and of 1958, a solar cycle maximum year. To fill major gaps in the world coverage of observed data for these years, we used some supplementary data observ...

Jean E. Adams, “Measurements of the Performance of Two HF log Periodic Antennas at the Lincoln Receiving Site of McClellan AFB,” Technical Memorandum IER TM ITSA 94, June 1967

Antenna performance measurements were made on five HF antennas to determine their acceptance as prototype antennas for the Air Force HF communication circuits. The impedances. power gain, and radiation patterns of two of the log periodic antennas are...

Laurance G. Hause and C. F. Peterson, “Passive reflector measurements at 9.2 and 4.6 GHz,” Technical Memorandum IER TM ITSA 64, June 1967

1. Path loss median values can be substantially greater than one might expect from simple line-of-sight calculations especially where one leg of the path is very long. 2. Small passive reflectors have application at frequencies considerably below 4 ...

C. F. Peterson, Charles A. Samson, Joseph E. Farrow, and Evelyn M. Gray, “Radio and Meteorological Observations on an obstacle diffraction communication link in Europe, Radio and Meteorological Observations on the 11. 1 -46 Radio Link of the ET-A System,” Technical Memorandum IER TM ITSA 65, June 1967

An investigation of the performance of a 405 km obstacle-diffraction radio link between Germany and Italy was made during June and July 1966 to evaluate contributions of both the antenna system and local meteorological conditions to propagation outa...

M. E. Johnson, Martin J. Miles, Paul L. McQuate, and Albrecht P. Barsis, “Tabulations of VHF Propagation Data Obtained Over Irregular Terrain at 20, 50, and 100 MHz,” Technical Report IER 38-ITSA 38, May 1967

This report contains tabulations of transmission loss data resulting from propagation experiments at 20, 50, and 100 MHz conducted over irregular terrain in the Colorado high plains east of the Continental Divide. Raw data from measurements describe...

Herman V. Cottony, “Measurement of antenna radiation efficiencies,” Technical Memorandum IER TM ITSA, May 1967

The definition of radiation efficiency is stated and the principles and practice s in measuring it are reviewed. Particular attention is given to the rhombic antenna because of its practical importance at HF and because its efficiency can be determin...

James R. Wait and Eileen A. Brackett, “Bibliography on Waves in Plasmas,” Bibliography IER 39-ITSA 39, April 1967

Bibliography on Waves in Plasmas

James C. Blair, “Monitoring techniques for evaluating useful frequencies for HF telecommunication circuits,” Technical Memorandum IER TM ITSA, March 1967

Significant channel characteristics of HF communication circuits are reviewed, with particular emphasis on their importance in the evaluation and selection of useful operating frequencies. Various theoretical and experimental results from several sou...

R. Marshall Coon and W. D. Bensema, “Instrumentation and analysis technique for the measurement of HF channel characteristics,” Technical Memorandum IER TM ITSA 11, March 1967

This report describes a means of measuring and analyzing the transfer characteristic of an HF channel in terms of the effects of the medium on 229 closely spaced sinusoids. The method involves transmission, reception, measurement, and computer analys...

Robert T. Disney, Arthur D. Spaulding, William Q. Crichlow, and R. C. Davis, “Minuteman Radio Launch Control System Studies and Site Survey,” Technical Memorandum IER TM ITSA 32, March 1967

To evaluate the performance of the Minuteman Radio Launch Control System, a number of factors were investigated. This report gives the results of the field measurement programs conducted by ITSA. In addition to the radio noise evaluation, measurement...

G. D. Gierhart and M. E. Johnson, “Interference Predictions for VHF/UHF Navigation Aids,” Technical Report IER 26-ITSA 26, March 1967

Desired-to-undesired signal ratio predictions for the VHF Omnirange (VOR), Tactical Air Navigation (TACAN) and Instrument Landing Systems (ILS) air navigation aids are presented in this report. The parameters involved in the various systems are given...

Douglass D. Crombie and James M. Watts, “Observations of coherent backscattering of hectometric radiowaves from along the sea surface,” Technical Memorandum IER TM ITSA, February 1967

Observations of coherent backscatter from the surface of the sea, at range s up to 200 km, using a slightly modified ionosonde are described. The range of frequencies used was between 2.6 and 8.5 MHz corresponding to sea wave lengths of 58 -17m and ...