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Spectrum Engineering Reports

NOTE: These reports are available either on-line in PDF (portable document) format or only as hard-copy. If you would like a copy of a report that is not available electronically, please make note of the document number and submit your request to:

NTIA Office of Spectrum Management
System Engineering and Analysis Division
Tel. (202) 482-2608
Fax (202) 482-4595

Meteor Burst System Communications Capability (30-100 MHz)

Report ID
TR 89-241
March 01, 1989

The technical and operating characteristics of meteor burst systems of importance for spectrum management applciations are identified. A technical assessment is included which identifies the most appropriate frequency subbands within the VHF spectrum to support meteor burst systems. The electromagnetic compatibility of meteor burst systems with other equipments in the VHF spectrum is determined using computerized analysis methods for both ionospheric and groundwave propagation modes. It is shown that meteor burst equipments can cause and are susceptible to groundwave interference from other VHF equipments. The report includes tables of geographical distance separations between meteor burst and other VHF equipments which satisfy interference threshold criteria.

Handbook of Radio Wave Propagation Loss, Part II (100-20,000 MHz)

Report ID
TR 89-242
April 01, 1989

This handbook is intended to provide estimates of radio wave propagation loss between transmitting and receiving antennas of various heights and transmission frequencies above the assumed smooth-earth surface calculated using the NLAMBDA computer model. For many cases involving electromagnetic compatibility analysis, the curves of predicted transmission losses in this report may be used to estimate the transmission losses of the desired and undesired signals. These estimated loss values are given in dB as BASIC MEDIAN TRANSMISSION LOSS for antennas with effective heights up to 5000 meters, operating in the 100-20,000 MHz frequency range, over land or sea, at great circle earth surface distances up to 1000 kilometers.

Conservation Techniques for Fixed Microwave Systems (7125-8500 MHz)

Report ID
TR 89-243
May 01, 1989

Since the spectrum is a limited natural resource, the spectrum management community has a major interest in identifying spectrum conservation techniques that will provide more efficient spectrum utilization. Advances in new technology for fixed microwave systems in antennas, modulation schemes and signal processing techniques offer increased efficiency in spectrum utilization. This report analyzes the spectrum conserving properties of the various new technologies for fixed microwave systems applying the concepts in CCIR Report 662-2, and was defined as the spectrum conservation factor (SCF). The report concludes that the SCF technique is an effective indicator of the spectrum conserving properties of technologies which can be used to develop new spectrum standards.

Spectrum Resource Assessment of Government Use of the HF (3-30 MHz) Band

Report ID
TM 89-141
June 01, 1989

This report is a spectrum resource assessment of the HF band (3-30 MHz). It incudes information on rules, regulations, allocations, technical standards, frequency assignments, system characteristics, and special uses unique to the HF band. The impact on HF services brought about by new technologies is discussed along with potential impacts of HF Over-the-Horizon (OTH) radars and ionospheric sounders. The importance of domestic emergency communciations in the HF band is discussed along with new standards for interoperability presently being drafted.

Procedure for Calculating the Power Density of a Parabolic Circular Reflector Antenna

Report ID
TM 90-145
February 01, 1990

This technical report details a procedure for calculating the mainbeam off-axis power density in the near- and far-field of a parabolic circular reflector antenna. In the report, the on-axis procedures of an earlier report are extended to off-axis analysis. Like its predecessors, it is intended for general use in system planning and evaluation and gives a worst-case estimate for radiation hazard assessment.

Hydrologic and Meteorological Operations in the 162-174 and 406.1-420 MHz Bands

Report ID
TR 90-259
March 01, 1990

Use of Government and non Government flood warning systems in the 162-174 MHz band are growing rapidly in the US. The report investigated ways of improving the spectrum efficiency of these systems to allow for continued growth. Recommendations for narrowing channel widths and allotting certain channels for their use have been adopted.

Ground-Based Weather Radar Compatibility with Digital Radio-Relay Microwave Systems

Report ID
TR 90-260
March 01, 1990

Interference from high powered weather radars to digital microwave systems is a growing problem in the US. The study identified procedures to avoid these problems. The study was completed in coordination with the FCC and industry. Recommendations dealing with exchange of data bases, coordination procedures and other technical areas have been adopted.