The electromagnetic spectrum is a vital part of our environment. Yet-to-be-discovered knowledge is encoded in the spectrum of radiation that is arriving at Earth from the depths of the universe. For example, the cosmic microwave background, pulsars, and binary pulsars were respectively discovered by Nobel Prize-winning radio astronomers Arno Penzias and Robert Wilson; Antony Hewish; and Russell A. Hulse and Joseph H. Taylor, Jr. Radio astronomers Aleksander Wolszczan and Dale Frail discovered the first extrasolar planets. Other radio astronomers study a wide range of subjects, from the era before the first stars formed to the dynamics of our own Sun. Closer to home, our understanding of Earth’s land masses and oceans, its biosphere, the many layers of the atmosphere, and the space around Earth is essential to humanity’s safety and well-being. Some radio-frequency measurements of these natural phenomena have immediate economic benefits; others underlie our view of what we are and of our place in the cosmos. The spectrum is therefore a resource to be used wisely now and to be protected for future generations.
The Panel on Frequency Allocations and Spectrum Protection for Scientific Uses arrived at several key considerations related to scientific use of the spectrum. They are in the areas of scientific impact, sensitivity, stewardship, requirements, and opportunity and challenge:
Scientific impact—Radio-frequency measurements of natural phenomena provide essential information with broad scientific and economic impacts.
Sensitivity—Receive-only (“passive”) measurements of weak natural signals in a broad range of frequencies must be made with extreme sensitivity.
Stewardship—The extreme sensitivity required makes it essential to maintain protected allocations and also to properly manage use of the spectrum near the protected allocations.
Requirements—Dedicated passive allocations exist only in a limited number of bands. There is need for protection of some bands essential to scientific and societal interests that are not now protected.
Opportunity and challenge—The receive-only services can sometimes take advantage of uncongested spectra not allocated to them. Increasing congestion may deny this capability in the future.
By its very nature, research uncovers new and often unexpected pathways for studying our terrestrial environment and the universe. It is important to recognize that the passive services are always “starved” for sensitivity.1 The signal-to-noise ratio is limited only by the sensitivity of the receiving instruments and the noise in the environment; passive services do not have the option of increasing the “signal” from the source. If the instruments are to achieve their theoretical limit, the environment must not be contaminated.
This handbook contains practical information regarding the use of the radio spectrum for scientific research. In Chapter 1, the regulatory bodies and issues are described. Chapter 2 discusses the relevant scientific background necessary to an understanding of the issues with spectrum management. Chapter 3 lists the science service spectrum allocations in the United States and their uses. Chapter 4 discusses issues related to spectrum protection.
In addition, the report has a number of appendixes. Appendix A offers National Telecommunications and Information Administration definitions concerning interference. Appendix B provides examples of footnotes to science services allocations. Appendix C lists important International Astronomical Union (IAU) spectral lines below 300 GHz. Appendix D lists important IAU spectral lines above 300 GHz. Appendix E presents selected Federal Communications Commission rules and regulations. Appendix F lists International Telecommunciation Union recommendations pertaining to radio astronomy, space applications, and meteorology. Appendix G lists Earth science passive sensor needs above 71 GHz. Appendix H examines the use of 0 dBi for sidelobe gain in calculations of interference in radio astronomy. Appendix I lists selected acronyms from the text.