Handbook of Frequency Allocations and Spectrum Protection for Scientific Uses (2007) / Chapter Skim
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3 Science Service Allocations
3 Science Service Allocations
Pages 38-78
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From page 38... ...
Furthermore, if Figure 3.2 showed absorption rather than transmission, the lines of particular importance to the Earth Exploration-Satellite Service (EESS) would be readily apparent: namely, the water lines at 22.235 and 183.1 GHz and the oxygen lines around 55-60 GHz and 118.75 GHz, as well as the available windows needed for comparison purposes, surface observations, and communications.
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From page 39... ...
FCC Online Table of Frequency Allocations, as well as the Radio Regulations, for the latest information. The Redbook can be found at http://www.ntia.doc.gov/ osmhome/redbook/redbook.html, and the FCC's document can be found at http://www.fcc.gov/ oet/spectrum/table/fcctable.pdf.
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From page 40... ...
Klein, "The Sensitivity of Millimeter and Sub-millimeter Frequencies to Atmospheric Temperature and Water Vapor Variations," Journal of Geophysical Research-Atmospheres, Vol.
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From page 41... ...
3.2.3 Interstellar Medium The low-frequency range below 1 GHz also has a great importance in the observations of both the thermal and nonthermal diffuse radiation in our own Milky Way Galaxy. Such galactic observations give information about the high-energy cosmic ray particles in our Galaxy and about their distribution, and also about the hot ionized plasma and star birth in the disk of our spiral Galaxy.
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From page 42... ...
5.279A Biomass and soil measurements 460-470 See NTIA Redbook NOAA (EESS) communications bands RAS,23 mss24 5.149, 5.208A, US74, US24625 608-614 Sun, interstellar medium, steep spectrum sources, pulsars Several hundred such galactic clouds appear approximately as blackbodies at frequencies below ~100 MHz.
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From page 43... ...
3.2.5 Steep-Spectrum Continuum Sources Most radio sources (such as radio galaxies, quasars, and supernova remnants) have characteristic nonthermal spectra produced by synchrotron emission from relativistic cosmic ray electrons moving in galactic-scale magnetic fields.
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From page 44... ...
High-resolution observations of radio galaxies and quasars have also been made with the GMRT using the method of lunar occultations, which uses the lunar disk to eclipse distant radio sources as they move across the sky. From such occultations, it has been possible to determine the shapes and positions of many extragalactic radio sources with very high accuracies, on the order of 1 arc second.
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From page 45... ...
3.3.1 Neutral Atomic Hydrogen One of the most important spectral lines at radio wavelengths is the 21 cm line (1420.406 MHz) , corresponding to the F = 1 → 0 hyperfine transition of neutral atomic hydrogen (HI)
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From page 46... ...
, eess (passive) , Extragalactic radio sources, galactic FS, MS, FSS, BSS continuum
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From page 47... ...
235.355 adds FS on a secondary basis in certain countries. 245.359 adds FS on a primary basis in certain counties but urges administrations to make no additional allocations.
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From page 48... ...
51US211 urges protection of adjacent RAS bands. 52US99 requires the advance notification of use of radiosondes in the 1668.4-1670 MHz band.
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From page 49... ...
Use of the OH line to study these very peculiar and active galaxies allows radio astronomers to diagnose the temperature and density of the molecular gas in the centers of these galaxies. 3.3.3 Extragalactic Radio Source Spectra The study of the continuum emission of radio sources requires observations throughout a very wide frequency range.
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From page 50... ...
3.3.5 Very Long Baseline Interferometry Because of the sensitive, large antennas of the NASA Deep Space Network and other deep space stations, the 2290-2300 MHz band allocated to the Space Research Service (SRS) is also used for VLBI observations in radio astronomy.
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From page 51... ...
The frequency bands near 2300, 2700, and 5000 MHz are important bands for polarization measurements. 3.3.7 Soil Moisture A combination of active and/or passive microwave measurements can be used to remotely sense soil moisture under moderately vegetated areas (up to ~5 kg/m2 of vegetation water content)
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From page 52... ...
at 4829.66 MHz. This line is a useful tracer of the more diffuse interstellar medium because it can be detected in absorption against strong background radio sources.
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From page 53... ...
FS, MS,28 SRS (E→S) , 7190-7235 5.458 Deep space uplinks, passive remote (eess passive)
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From page 54... ...
19US211 urges protection from aeronautical and space stations in adjacent bands. 20US246 prohibits transmissions.
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From page 55... ...
These radio maps define the extent and detailed morphology of radio sources and enable us to make conclusions concerning their structures and dynamics and to derive physical parameters of the sources such as their total masses. Heavy use has been made of the radio astronomy band at 5 GHz for VLBI observations.
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From page 56... ...
Microwave radiometric measurements within TABLE 3.4 Frequency Allocations Between 10 and 25 GHz: Bands, Services, Footnotes, and Scientific Uses Band (GHz) Services Footnotes Scientific Use 5.149,2 5.482,3 US265,4 US2775 Precipitation, continuum, VLBI 10.6-10.68 EESS (passive)
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From page 57... ...
25.149 urges protection of RAS from other services and particular airborne and space stations. 35.482 limits the power of FS and MS stations.
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From page 58... ...
on a secondary basis. 47US211 urges protection of nearby radio astronomy band.
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From page 59... ...
They are occasionally the most intense radio sources in the sky at 22.2 GHz. It was soon discovered that the intensities of these lines are highly variable, that the sizes of the H2O sources are extremely small (a few astronomical units)
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60 HANDBOOK OF FREQUENCY ALLOCATIONS AND SPECTRUM PROTECTION FOR SCIENTIFIC USES FIGURE 3.3 Combined radio and optical images of M33 (Triangulum Galaxy)
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From page 61... ...
3.5.7 Soil Moisture See §3.3.7 for applications of soil moisture. 3.5.8 Snow Cover Snow cover and snow water equivalent are derived from microwave radiometric imagery primarily at 18, 23, and 37 GHz, with atmospheric sounding data to remove the atmospherically induced noise in the retrieval.
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Sea-surface wind direction may also be derived using highly sensitive passive polarimetric measurements at 10, 18, 23, and 37 GHz. This technique has been demonstrated with several airborne campaigns and the WindSat spaceborne passive microwave sensor.
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From page 63... ...
is also detectable, albeit with somewhat less confidence. Ice motion is generally detectable using microwave radiometric imagery to ~1 km per day motion, depending on the atmospheric and surface state.
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From page 64... ...
In addition to the lists in the tables in this handbook, a list of useful microwave bands and radiometric imagery products can be found in ITU-R SA.515. 3.5.14 Sea-Surface Temperature Sea-surface temperature is measured using passive microwave channels at 10.7 GHz.
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From page 65... ...
, RAS 5.149,42 5.340,43 5.555,44 48.94-49.04 RAS, FS, FSS, MS CS US264,45 US297,46 US342 NOTE: For definitions of acronyms and abbreviations, see Appendix I For information about other features of this table, see §3.1.2, "Note to the Reader Regarding Frequency Allocation Tables." 15.536 limits ISS to SRS, EESS, and IMS applications.
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From page 66... ...
195.149 urges protection of RAS in the 31.5-31.8 GHz band in Regions 1 and 3, particularly from space and airborne stations. 205.546 allocates this band to FS and MS on a primary basis in certain countries.
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From page 67... ...
3.6.2 SiO Masers The 42.5-43.5 GHz band contains the lowest rotational transitions (J = 1 → 0) of vibrational states of SiO.
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Currently, atmospheric temperature profiles are measured using LEO satellite microwave sounders. A number of present-day technological developments are enabling the future deployment of a geostationary orbiting microwave temperature sounder.
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From page 69... ...
175.557 adds RLS on a primary basis in Japan. 185.558 allows AeMS subject to not causing interference to ISS.
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From page 70... ...
The spectrum within 102 and 126 GHz is not entirely allocated to EESS passive, but rather is broken into 102-105 GHz, 105-109.5 GHz, 109.5-111.8 GHz, 114.25-116 GHz, 116-119.98 GHz, and 119.98-122.25 GHz segments with different sharing services. EESS passive service is allocated only in the 109.5-111.8 GHz and 114.25-122.25 GHz bands.
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From page 71... ...
For information about other features of this table, see §3.1.2, "Note to the Reader Regarding Frequency Allocation Tables." 1In the United States only. 25.149 urges protection of RAS in this band.
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From page 72... ...
The 100-102 GHz band is used for radio astronomy observations of redshifted CO in distant galaxies. The 200-300 GHz band contains the second available rotational line of carbon monoxide (12C16O)
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From page 73... ...
3.8.6 Atmospheric Temperature Profile The atmospheric temperature profile can be derived using passive radiometric measurements on and near the 118.75 GHz O2 transition. Temperature profiles derived from this band complement those derived using the 50-60 GHz complex by providing independent measurements, albeit with reduced sensitivity at higher altitudes and less penetrability of clouds and precipitation.
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From page 74... ...
For climate measurements, cloud base height is critical for determining the long-wave energy budget at Earth's surface, and for understanding the impacts of anthropogenic aerosols on cloud formation, precipitation, and short- and long-wave energy fluxes. 3.8.9 Microwave Radiometric Imagery See §3.5.13 for applications of microwave radiometric imagery.
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From page 75... ...
75 SCIENCE SERVICE ALLOCATIONS TABLE 3.8 Frequency Allocations Between 126 and 400 GHz: Bands, Services, Footnotes, and Scientific Uses Band (GHz) Services Footnotes Scientific Use 5.149,1 5.340,2 5.5553 140.69-140.98 MS, MSS, RAS, RNS, H2CO RNS, rls RLS, aems, aemss, RAS4 H2CO, DCN (Note: DCO+ at 144.68-147.12 5.149, 5.555 144.07 GHz)
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From page 76... ...
For information about other features of this table, see §3.1.2, "Note to the Reader Regarding Frequency Allocation Tables." 15.149 urges protection of RAS. 25.340 forbids emissions from airborne stations and from space stations toward Earth between 140.69 and 140.98 GHz.
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From page 77... ...
Passive measurements near the strong 183.31 GHz water-vapor line, aided by measurements in the adjacent transmission window at the EESS-allocated bands of 150-151 GHz or 164-168 GHz, are critical for the global measurement of atmospheric water vapor profiles. Measurements from spaceborne sensors in LEO are carried out to obtain atmospheric water-vapor profiles from Earth's surface to 100 mb with a measurement uncertainty of ~20 percent and ~35 percent for clear and cloudy conditions, respectively.
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From page 78... ...
3.9.5 Atmospheric Chemistry The first Microwave Limb Sounder (MLS) on NASA's Upper Atmosphere Research Satellite used channels near 63, 183, and 205 GHz to measure emissions of chlorine monoxide, water vapor, ozone, and sulfur dioxide.
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