Spectrum Management for Science in the 21st Century

This book addresses the tension between the active services' demand for greater spectrum use and the passive users' need for quiet spectrum. The included recommendations provide a pathway for putting in place the regulatory mechanisms and associated supporting research activities necessary to meet the demands of both users.



Radio observations of the cosmos are gathered by geoscientists using complex earth-orbiting satellites and ground-based equipment, and by radio astronomers using large ground-based radio telescopes. Signals from natural radio emissions are extremely weak, and the equipment used to measure them is becoming ever-more sophisticated and sensitive.

The radio spectrum is also being used by radiating, or "active," services, ranging from aircraft radars to rapidly expanding consumer services such as cellular telephones and wireless internet. These valuable active services transmit radio waves and thereby potentially interfere with the receive-only, or "passive," scientific services. Transmitters for the active services create an artificial "electronic fog" which can cause confusion, and, in severe cases, totally blinds the passive receivers.

Both the active and the passive services are increasing their use of the spectrum, and so the potential for interference, already strong, is also increasing.

Contents
SUMMARY
1 INTRODUCTION
1.1 The Passive Radio Spectrum
1.2 Prospects for Future Scientific Use of the Radio Spectrum
1.3 The Interference Problem
1.4 Interference Mitigation
1.5 Enabling Scientific Uses of the Radio Spectrum
2 THE EARTH EXPLORATION-SATELLITE SERVICE
2.1 Specific Application Areas of Passive Microwave Remote Sensing
Weather Forecasting and Monitoring
Severe Weather and Disasters
Climate and Global Change
Resource Management
Aviation
Defense and Public Safety
International Partnerships
Education and Technology
2.2 Brightness Temperatures, Geophysical Measurements, and Missions
Fundamentals of Microwave Radiometry for EESS Applications
Measurement of Specific Geophysical Parameters
2.3 Current and Future Space Missions, Activities, and Spectrum Usage
2.4 Current and Future Non-Space-Based Activities and Spectrum Usage
2.5 The Impact of Radio Frequency Interference on Earth Exploration-Satellite Service Observations
Introduction to the Problem of Radio Frequency Interference: Immediate Impacts on EESS
Evidence of Impact of Radio Frequency Interference on EESS Observations
Potential Future Radio Frequency Interference and Its Impact on EESS Observations
2.6 Summary of the Importance of and Risks to Continued Contributions of the Earth Exploration-Satellite Service in the Future
3 THE RADIO ASTRONOMY SERVICE
3.1 The Scientific Impact of Radio Astronomy
Origin of Planets and the Solar System
Origin and Evolution of the Universe
Pulsars and General Relativity
Galactic Nuclei and Black Holes Galaxies
Solar Physics and Space Weather
Serendipity and the Transient Universe
Summary
3.2 Radio Observatories and Radio Telescopes
3.3 Spectrum Requirements and Use
Continuum and Line Observations
Atmospheric Windows and Absorption Features
Current Radio Astronomy Service Allocations
Spectrum Use
3.4 Sensitivity Requirements
Sensitivity Limits
3.5 Interference and Its Mitigation
Examples of Interference in a Protected Band
Mitigation
3.6 Importance of Radio Astronomy to the Nation
Radio Interferometry
Communications Disruptions
Fundamental Physics
Technology Development
Precision Antennas
Distributed Network Computing
Education and Public Outreach
4 Technology and Opportunities for the Mitigation of Radio Frequency Interference
4.1 Trends in Active Spectrum Usage
Current Allocations
Current Utilization Studies
4.2 Major Drivers of Spectrum Use
Assessment of Trends in Spectrum Use for 2008–2015
Third-Generation and Fourth-Generation Systems
Unlicensed Uses of the Radio Frequency Spectrum
Regulatory Changes That Impact Use
Technology Changes That Impact Use
Summary
4.3 Unilateral Mitigation Techniques
Technologies for Unilateral Mitigation
4.4 Mitigation Through Cooperative Spectrum Usage
4.5 Mitigation Costs, Limitations, and Benefits
Earth Exploration-Satellite Service (EESS)
Radio Astronomy Service (RAS)
Nature of the Costs of Radio Frequency Interference to the EESS and the RAS
Summary
5 FINDINGS AND RECOMMENDATIONS
5.1 Societal Value of the Passive Services
5.2 Characteristics of the Passive Spectrum Services
5.3 Threats to the EESS and the RAS from Unintentional Radio Frequency Interference
5.4 Technology for Mitigation of Radio Frequency Interference
5.5 Protection of the EESS and the RAS
5.6 The Path Forward
5.7 Conclusion
APPENDIXES
A Statement of Task
B Biosketches of the Committee Members
C Density of Interferers Equation
D Analysis of Out-of-Band Emission Impacts to the EESS from §27.53 of the FCC Rules
E Descriptions of Earth Exploration-Satellite Service Parameters Related to Table 2.1
F Acronyms and Abbreviations
G Glossary