Search Results

The search returned 1,237 publication(s) on its.ntia.gov.

Arthur A. Webster et al., “An objective video quality assessment system based on human perception,” Conference Paper, February 1993

The Institute for Telecommunication Sciences (ITS) has developed an objective video quality assessment system that emulates human perception. The system returns results that agree closely with quality judgements made by a large panel of viewers. Such...

Hans J. Liebe, George A. Hufford, and Michael G. Cotton, “Polarized Transmission and Emission in the Middle Atmosphere (25–150 km) Near the Zeeman-Split Microwave O2 Lines,” Conference Paper, January 1993

Gaseous atmospheric attenuation and delay properties in the 50 to 75-GHz band and near 119 GHz are dominated by the fine structure lines of molecular oxygen. With increasing altitude the complex refractivity displays spectral patterns which change f...

Fredrick Wentland, Richard Smith, and Carl A. Winkler, “Evaluation of Spectrum Management in Nicaragua,” Technical Memorandum NTIA TM-93-158, January 1993

Mark Bykowski et al., “Globalization of the Mass Media,” Special Publication NTIA SP-93-290, January 1993

This report reassesses U.S. communications and mass media policies in light of the increasingly global nature of the electronic mass media. A basic theme of this report is that the United States cannot afford to be complacent about the success of U.S...

Peter B. Papazian et al., “Wideband Propagation Measurements for Wireless Indoor Communication,” Technical Report NTIA TR-93-292, January 1993

Wideband impulse response measurements were made to characterize proposed radio data channels in three indoor environments. The measurement system employed a 1.5 GHz carrier which was biphase shift key (BPSK) modulated using a 100 Mb/s pseudo-random ...

Christopher J. Behm and John J. Lemmon, “Wideband HF Noise/Interference Modeling, Part II: Higher-Order Statistics,” Technical Report NTIA TR-93-293, January 1993

This report is the second in a series of reports which describe the development of a wideband HF noise/interference mode. The model is based on measured data and is suitable for implementation in a wideband HF channel simulator. The measured data, an...

Institute for Telecommunication Sciences, “FY 1992 Technical Progress Report,” Technical Progress Report, January 1993

The Institute for Telecommunication Sciences (ITS) is the research and engineering laboratory of the National Telecommunications and Information Administration (NTIA) of the U.S. Department of Commerce (DOC). ITS provides technical support to NTIA in...

David A. Sutherland Jr., “Simulated Effects of Sounding on Automatic Link Establishment HF Radio Network Performance,” Technical Report NTIA TR-93-291/NCS TIB 92-21, December 1992

A discrete event simulation model for an HF Automatic Link Establishment (ALE) radio network is described. The simulation model is based on Federal Standard 1045 “Telecommunications: HF Radio Automatic Link Establishment.” The simulation is used to ...

Hans J. Liebe, George A. Hufford, and Michael G. Cotton, “Progress in Atmospheric Propagation Modeling at Frequencies below 1000 GHz,” Conference Paper, December 1992

Millimeter-wave propagation through the nonprecipitating atmosphere is modeled for frequencies below 1000 GHz. Complex refractivities represent the spectral properties of four natural absorbers; that is, oxygen, water-vapor, suspended droplets and i...

Christopher Redding and William J. Pomper, “Linking protection in Federal Standard 1045 HF radios using the data encryption standard,” Technical Report NTIA TR-92-289, December 1992

A method of utilizing the Data Encryption Standard (DES) algorithm for linking protection in HF radios complying with Federal Standard 1045 is described. The unique DES encryption method, which permits a codebook type of encryption of 24-bit words, i...

George A. Hufford, “A Characterization of the Multipath in the HDTV Channel,” Journal Article, December 1992

The Institute for Telecommunication Sciences (ITS) has recently completed a program to measure the impulse responses of channels that would probably be used in over-the-air HDTV. To help in the analysis of these measurements, we have developed a...

Hans J. Liebe, Philip W. Rosenkranz, and George A. Hufford, “Atmospheric 60-Ghz Oxygen Spectrum: New Laboratory Measurements and Line Parameters,” Journal Article, December 1992

Over 5000 absolute absorption values for pressure-broadened O2 lines in dry air were measured at frequencies from 49 to 67 GHz in 0.1-GHz-increments. The controlled laboratory studies were carried out at three temperatures (6, 30, and 54°C) for 11 ...

David Anderson and David J. Cohen, “Digital emission spectrum model,” Technical Report NTIA TR-92-288, November 1992

A computer program was developed to calculate the power spectral density (PSD) and the fractional power containment bandwidth for various digital modulation techniques. The power containment capability was used to provide guidance for determination o...

Peter B. Papazian, David L. Jones, and Richard H. Espeland, “Wideband Propagation Measurements at 30.3 GHz Through a Pecan Orchard in Texas,” Technical Report NTIA TR-92-287, September 1992

Wideband propagation measurements were made in a pecan orchard in Texas during April and August of 1990 to examine the propagation characteristics of millimeter–wave signals through vegetation. Measurements were made on tree obstructed paths with and...

Gerald F. Hurt and Philip E. Gawthrop, “Feasibility of Relocating Non-Government Fixed Systems into the 1710–1850 MHz Band,” Technical Report NTIA TR-92-286, August 1992

Coleen T. Jones, Stephen Wolf, and Margaret H. Pinson, “Preliminary Results of One-Way Video Delay Measurement Algorithms,” Technical Contribution, July 1992

Out-of-service measurements can be used to obtain a baseline video system delay. However, in many digital video systems, video delay is dynamic and dependent upon the scene content. This contribution describes an objective measure of video delay that...

Stephen Wolf, “An Automated Technique for Measuring Transmitted Frame Rate (TFR) and Average Frame Rate (AFR),” Technical Contribution, July 1992

The motion difference images of the original and degraded video sequences is used to dynamically measure the Transmitted Frame Rate (TFR) and the Average Frame Rate (AFR) of a digital video system codec (coder-decoder). The TFR measurement algorithm ...

Stephen D. Voran, “The Effect of Multiple Scenes on Objective Video Quality Assessment,” Technical Contribution, July 1992

Presents objective to subjective correlation results when the scores from multiple video test scenes are averaged. It is shown that the prediction errors of the objective video quality model are reduced, yielding objective measurement results that mo...

Stephen D. Voran and Stephen Wolf, “The Development and Evaluation of an Objective Video Quality Assessment System that Emulates Human Viewing Panels,” Conference Paper, July 1992

Discusses the approach used and the research conducted to develop an objective video quality assessment system that emulates human perception. The system returns results that agree closely with quality judgments made by a large panel of viewers for t...

Herbert K. Kobayashi and Gary M. Patrick, “Preliminary Building Attenuation Model,” Technical Memorandum NTIA TM-92-155, May 1992

In this technical report, preliminary graphical models spanning approximately 1 MHz to 30 GHz are developed for commercial and residential building attenuation. The models are least-square fits to the data available from the open literature. An estim...