in force · incorporated by reference in the RR · 2023

Catalogs the spectral-line rest frequencies and continuum bands radio astronomy needs below 1000 GHz, tied to atomic/molecular physics from the IAU list: neutral hydrogen at 1420.406 MHz, OH near 1612–1720 MHz, water vapour at 22.235 GHz, CO at 115/230 GHz. Bands widen to cover Doppler and redshift. Flags where current RR allocations are non-primary, too narrow, or absent.

Why it matters — Defines which frequencies the science actually requires — the demand side of every sharing and allocation decision.

in force

Addresses protection of observations made from the shielded zone of the Moon — the lunar far side, screened by the Moon's body from Earth-origin emissions — identifying it as a uniquely interference-free site and the bands warranting protection there.

Why it matters — The lunar far side is the quietest location in the inner solar system; matters increasingly as lunar and cislunar activity grows.

in force

Provides methods to protect RAS from adjacent-band transmitters, including the projection of the geostationary orbit onto the sky as seen from observatory latitudes and the resulting frequency and angular-separation requirements.

Why it matters — Adjacent-band emissions are a primary leakage path into sensitive RAS bands; underpins the coordination geometry used elsewhere in the series.

in force · 2006

Protects RAS from spurious, harmonic and intermodulation emissions of transmitters outside RAS bands. Notes RR Appendix 3 spurious limits are not directly applicable to digital modulation. Worked example: an airborne 2-PSK transmitter can produce pfd ~40 dB above RA.769 thresholds in a RAS band far from its carrier. Directs satellite cases to the epfd tools.

Why it matters — Shows a fully in-band-compliant neighbour can still ruin observations through out-of-band products.

in force · incorporated by reference in the RR · 2003

The foundational protection criterion. Defines harmful interference as a 10% error in the measured noise fluctuation (ΔPH = 0.1·ΔP·Δf) over a 2000 s integration, and tabulates detrimental pfd/spectral-pfd per band from ~13 MHz to 270 GHz at 0 dBi side-lobe gain. Handles the GSO case (5° spacing, −15 dB) and the non-GSO case (epfd, RR No. 22.5C).

Why it matters — The quantitative definition of 'harmful' that every sharing study and BR examination measures against.

in force

Sets criteria and methods for protecting RAS in bands it shares with active services, including the tolerable-interference time criterion (2% of time for a shared service) and guidance on when band sharing is feasible.

Why it matters — Most RAS bands are shared; this defines the practical terms of coexistence.

in force

Addresses interference to RAS from unwanted emissions of wideband digitally-modulated systems (including spread-spectrum), whose noise-like spectra spill far from the carrier and are hard to separate from cosmic signals.

Why it matters — Modern digital and spread-spectrum systems are a growing interference source that conventional masks handle poorly.

in force

Covers protection of RAS measurements above 60 GHz from ground-based interfering sources, reflecting the distinct propagation, attenuation and sharing conditions of the millimetre-wave regime.

Why it matters — Millimetre-wave astronomy is expanding rapidly, and its protection logic differs from lower bands.

in force

Recommends establishing a radio-quiet zone around the L2 Sun-Earth Lagrange point — a favoured location for space observatories — to preserve it from interference.

Why it matters — L2 hosts major space telescopes; protecting the region preempts future interference to irreplaceable missions.

in force · incorporated by reference in the RR · 2015

Adds the time dimension to RA.769: aggregate data loss to RAS ≤ 5% of time from all networks, and ≤ 2% from any single network, in primary RAS bands. Defines data loss, sky blockage (a source within 19.05° of the beam blocks 5.5% of sky), and how to compute the percentage via the epfd tools.

Why it matters — Pairs with RA.769 — the level plus the tolerable frequency together define harm.

in force

Gives the technical and operational characteristics of ground-based optical/infrared astronomy systems for use in sharing studies with active services between 10 and 1000 THz.

Why it matters — Extends coexistence analysis into the optical/IR regime as that spectrum sees active use such as lidar.

in force · incorporated by reference in the RR · 2003

Supplies the standard RAS antenna radiation pattern (a closed-form average side-lobe model above 150 MHz) for epfd-based non-GSO compatibility analysis, plus per-band typical maximum gains (63–93 dBi). Uses average rather than peak-envelope side-lobe levels so aggregate interference from constellations is not overstated.

Why it matters — The antenna half of the non-GSO toolchain: pattern (1631) + methodology (S.1586/M.1583) + threshold (769) + time criterion (1513).

in force

Establishes mutual planning arrangements between spaceborne EESS active sensors and RAS in the 94 GHz and 130 GHz bands, where both services have strong scientific interest.

Why it matters — Enables two high-value science services to share critical millimetre-wave bands rather than exclude each other.

in force

Identifies the preferred frequency bands for radio astronomical measurements in the 1–3 THz range, extending RA.314's band designations into the terahertz regime.

Why it matters — Terahertz astronomy is a growing frontier; this formalizes its spectrum needs before the band is contested.

in force

Describes global geodetic VLBI networks, whose observations underpin the international terrestrial reference frame, Earth-orientation parameters and timekeeping.

Why it matters — Geodetic VLBI is critical infrastructure for GNSS, navigation and Earth science, so its spectrum needs carry weight beyond astronomy.

Documents how pulsar timing observations provide a stable, independent time reference, and the observational requirements involved.

Why it matters — Pulsar timing supports precision timekeeping and tests of fundamental physics; frames the spectrum-protection needs of this work.

Surveys techniques radio astronomers use to mitigate RFI: time/frequency excision and blanking, spatial nulling, and reference-antenna cancellation.

Why it matters — Mitigation is part of the burden-sharing that makes coexistence feasible; this catalogs the state of the art.

Provides the derivation and supplementary data behind the detrimental threshold levels tabulated in RA.769.

Why it matters — The technical backing for the criteria examiners apply — needed to understand and defend the numbers.

Covers astronomical use of the 50–350 THz infrared band and its coexistence with other applications.

Why it matters — Brings optical/infrared astronomy into the ITU coexistence framework alongside radio bands.

Identifies pfd and e.i.r.p. levels that can physically damage sensitive RAS receivers, as distinct from merely degrading data.

Why it matters — Receiver damage is a hard limit that applies even where interference to data is otherwise managed.

Studies sharing between RAS and active services across 275–3000 GHz, where allocations are sparse and active use is only emerging.

Why it matters — Pre-positions coexistence rules before this high band fills up.

Examines how the transition to digital television changed the unprotected use by RAS of terrestrial TV broadcasting bands.

Why it matters — A documented real-world case of a spectrum transition altering RAS observing conditions.

Describes the characteristics, design and regulatory basis of radio quiet zones established around major observatories.

Why it matters — Radio quiet zones are a primary protection mechanism; this is the reference for establishing one.

Compatibility and sharing studies between RAS and IMT (mobile/5G) systems across eight specified band groups from 608 MHz to 5000 MHz.

Why it matters — IMT expansion is the largest current pressure on RAS bands; this gives band-specific results.

Sets threshold interference levels for protecting space-based radio astronomy observations.

Why it matters — Space telescopes need criteria distinct from ground stations, and this need is growing.

Defines the parameters needed to register distributed radio astronomy systems — arrays spread over wide areas — with the ITU.

Why it matters — Distributed and array systems do not fit single-station notification; this enables their formal registration and protection.

Studies coexistence between RAS and radiolocation applications, notably automotive radar, in the 76–81 GHz band.

Why it matters — Automotive radar is proliferating near RAS use; this quantifies the coexistence.

Documents the technical and operational characteristics of existing and planned geodetic VLBI systems (the VGOS network).

Why it matters — Supplies the system parameters needed to protect geodetic VLBI in sharing studies.

Describes widely-distributed radio astronomy array systems operating above 200 GHz, such as global VLBI at sub-millimetre wavelengths.

Why it matters — Characterizes cutting-edge high-frequency VLBI for protection purposes.

Gives the technical and operational characteristics of RAS systems operating below 350 MHz (metre wavelengths), including large low-frequency arrays.

Why it matters — Low-frequency arrays face heavy interference; this supports their sharing studies.

Documents the characteristics of RAS systems operating in the 67–116 GHz (3–4 mm) range.

Why it matters — A parameter reference for coexistence work in a heavily used millimetre-wave region.

Describes broadband, background-limited detectors operating in the millimetre-wave regime and their susceptibility to interference.

Why it matters — Modern wideband detectors change interference exposure; this informs protection assumptions.

Reports measurements of the impact of harmonic emissions at radio astronomy facilities.

Why it matters — Provides empirical evidence of harmonic interference to support RA.611-type protection.

Gives a methodology for coordinating IMT systems with RAS stations in the 42.5–43.5 GHz band.

Why it matters — A practical coordination recipe for a specific contested millimetre-wave band.

Provides methods to determine the coordination area around existing RAS stations relative to IMT stations in the 6650–6675.2 MHz band (a methanol spectral line).

Why it matters — Protects a specific important spectral-line band from IMT through defined coordination distances.