Previous Chapter: Appendix B: Report Recommendations
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.

C

Acronyms and Abbreviations

A-ESIMAeronautical Earth Station in Motion
AGBasymptotic giant branch
AGNactive galactic nuclei
ALMAAtacama Large Millimeter/submillimeter Array
AMSR2Advanced Microwave Scanning Radiometer 2
AMSR3Advanced Microwave Scanning Radiometer 3
AMSR-EAdvanced Microwave Scanning Radiometer for EOS
AMSU-AAdvanced Microwave Sounding Unit - A
ATMSAdvanced Technology Microwave Sounder (JPSS)
AWSArctic Weather Satellite
AWS PFMArctic Weather Satellite Proto-Flight Model
CEPTEuropean Post and Telecommunications Conference
CHIMECanadian Hydrogen Intensity Mapping Experiment
CIMRCopernicus Imaging Microwave Radiometer (ESA)
CITELInter-American Telecommunications Commission
CMAChina Meteorological Administration
CMBcosmic microwave background
DMSPDefense Meteorological Satellite Program
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
DoDDepartment of Defense
DSA-2000Caltech Deep Synoptic Array
ECMWFEuropean Centre for Medium-Range Weather Forecasting
EESSEarth exploration-satellite service
EOPEarth Orientation Parameters
EPAEnvironmental Protection Agency
epfdequivalent power flux-density1
ERA-5European Centre for Medium-range Weather Forecasting Reanalysis, version 5
ESAEuropean Space Agency
ESIMEarth station in motion
ETIextra-terrestrial intelligence
EUMETSATEuropean Meteorological Satellite agency
EVNEuropean VLBI Network
FASTFive-hundred-meter Aperture Spherical Radio Telescope
FEMAFederal Emergency Management Agency
FFTfast Fourier transform
FSSfixed-satellite service
FYFengYun
GBTGreen Bank Telescope
GCOM-WGlobal Change Observation Mission—Water
GMIGPM Microwave Imager
GNSSGlobal Navigation Satellite System

___________________

1Equivalent power flux-density (epfd) is defined in Radio Regulation (RR) 22.5C.1, in the context of protecting geostationary satellite systems from emissions of non-geostationary satellite systems, as “the sum of the power flux-densities produced at a geostationary-satellite system receive station on Earth’s surface or in the geostationary orbit, as appropriate, by all the transmit stations within a non-geostationary-satellite system, taking into account the off-axis discrimination of a reference receiving antenna assumed to be pointing in its nominal direction.” The reader is referred to the RR for the accompanying mathematical definition. The utility of the epfd concept is that it reduces the emissions of a complex set of transmitters to that of a single equivalent source, which simplifies the definition of interference thresholds. In the context of protecting radio astronomy observations from non-geostationary satellite systems, a similar definition of epfd is used, but involving a spatiotemporal average of satellite configurations that accounts for the long integration times used in these observations. The methodology is described in ITU-R S.1856-1 and produces epfd values that may be compared with the pfd interference thresholds defined in ITU-R RA.769-2.

Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
GOSAT-GWGreenhouse Gas Observing Satellite—Gases and Water Cycle
GPMGlobal Precipitation Measurement (NASA)
GPSGlobal Positioning System
GSFCGoddard Space Flight Center
GSOgeostationary orbit
HFhigh frequency [3–30 MHz]
HYHai Yang
ICIIce Cloud Imager
IEEEInstitute of Electrical and Electronics Engineers
IFOVinstantaneous field of view
IMTInternational Mobile Telecommunications
IPSinterplanetary radio scintillations
ISROIndian Space Research Organization
ISSInternational Space Station
ITUInternational Telecommunication Union
ITU-RInternational Telecommunication Union Radiocommunication Sector
JASONJoint Altimetry Satellite Oceanography Network
JAXAJapan Aerospace Exploration Agency
JPSSJoint Polar Satellite System
LEOlow Earth orbit
LOFARLow Frequency Array
MASERmicrowave amplification by stimulated emission of radiation
MATHSMillimetre wave Atmospheric Temperature and Humidity Sounder
MERLINMulti-Element Radio Linked Interferometer Network
MERRA-2Modern-Era Retrospective analysis for Research and Applications, version 2
M-ESIMMaritime Earth Station in Motion
Metop-SGMeteorological Operational Satellite – Second Generation
MSSmobile-satellite service
MSUMicrowave Sounding Unit
MTVZA-GYModule for Temperature and Humidity Sounding of the Atmosphere (named in honor of) G.Ya. Guskov (Russian)
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
MWAMurchison Widefield Array
MWIMicrowave Imager
MWRIMicrowave Radiation Imager
MWSMicro-Wave Sounder
MWTSMicro-Wave Temperature Sounder
NANOgravNorth American Nanohertz Observatory for Gravitational Waves
NASANational Aeronautics and Space Administration
NenuFARNew Extension in Nançay Upgrading LOFAR
NEOnear Earth object
ngVLANext Generation Very Large Array
NISARNASA ISRO SAR
NOAANational Oceanic and Atmospheric Administration
Non-GSOnon-geostationary orbit
NRQZNational Radio Quiet Zone
NSFNational Science Foundation
NSOASNational Satellite Ocean Application Service (China)
NWPnumerical weather prediction
OOBEout-of-band emission(s)
pfdpower flux-density
RAradio astronomy
RASradio astronomy service
RFIradio frequency interference
RLSRadiolocation Service
RNSSRadionavigation-Satellite Service
RosHydroMetRussian Federal Service for Hydrometorology and Environmental Monitoring
RQZradio quiet zone
RRradio regulation
SARsynthetic aperture radar
SETIsearch for extra-terrestrial intelligence
SKASquare Kilometre Array
SMAPSoil Moisture Active Passive
SMOSSoil Moisture and Ocean Salinity
SNPPSuomi National Polar-orbiting Partnership
spfdspectral power flux-density
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
SRSSpace Research Service
SSMISSpecial Sensor Microwave-Imager/Sounder
SSTsea-surface temperature
SWEsnow water equivalent
SZMShielded Zone of the Moon
TIROS-NTelevision and Infra-Red Observation Satellite
USAIDU.S. Agency for International Development
USDAU.S. Department of Agriculture
USGSU.S. Geological Survey
UWBRUltra-Wide Band Receiver
VHFvery high frequency [30-300 MHz]
VLAVery Large Array
VLBAVery Long Baseline Array
VLBIVery Long Baseline Interferometry
WMOWorld Meteorological Organization
WPTwireless power transmission
WRCWorld Radiocommunication Conference
WSFWeather Satellite Follow-on
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
Page 188
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
Page 189
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
Page 190
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
Page 191
Suggested Citation: "Appendix C: Acronyms and Abbreviations." National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: The National Academies Press. doi: 10.17226/28596.
Page 192
Next Chapter: Appendix D: International Telecommunication Union Reports and Regulations Cited in This Report
Subscribe to Emails from the National Academies
Stay up to date on activities, publications, and events by subscribing to email updates.