Value chain · CLM-1002
In plain terms
The 1981 study tells you exactly which international rulebooks it measured the satellite against, report by report, and warns that the second harmonic lands in the working band of America's biggest radio telescope even though no rule formally protects it there.
The claim as recorded
The 1981 EMC assessment names the instruments behind every protection criterion it applies: CCIR Report 224-4 for radio astronomy, Reports 365-3 and 685 for the space research service, Report 223 for protected spectral lines, Report 713 for interference to satellite systems, and Report 387-3 for terrestrial line-of-sight links, all from the 1978 Kyoto Plenary Assembly; and it states that the second harmonic at 4.9 GHz "does not fall into a currently allocated band of these services, but does fall well within the principal operating band of the Very Large Array" and at Arecibo's shortest usable wavelengths, so that "these facilities could be seriously compromised", with the VLA's tolerable margin over the CCIR levels falling to about 13 dB as the satellite belt's declination is approached.
Evidence behind this: T3-programme assessment naming its instruments by report number.
Scope and limits
THE MARGIN FIGURES ARE PARAPHRASED FROM THE 1979 WORKSHOP (SRC-516) AND THE TWO DOCUMENTS DISAGREE ON THE DECORRELATION FIGURE AT 25 MHz (14 or 17 dB), as CLM-0988's limits record. The numeric thresholds themselves are in CLM-0988, not on p.75.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF p.75, normalised: "Definitions of harmful interference to these services have been developed by the International Radio Consultative Committee (CCIR). CCIR Report 224-4 describes these criteria for radio astronomy, and CCIR Reports 365-3 and 685 give the criteria for the space research service." "The harmful spectral flux densities, specified in dB(W/m2-Hz), have been established as reasonable and measurable quantities, and an SPS would have to conform to those specifications... A list of such spectral lines is included in CCIR Report 223"; raw: "The strongest anticipated SPS harmonic, the second at 4.9 GHz, does not fall into a currently allocated band of these services, but does fall well within the principal operating band of the Very Large Array (VLA)... These facilities could be seriously compromised." PDF p.77, normalised: "as the declination of the satellite is approached, this margin falls to about 13 dB". PDF p.90, references: CCIR Recommendation 365-3, Reports 223-4, 224-4, 387-3, 391-3, 558-1, 685, 713 and 719, XIVth Plenary Assembly, Kyoto, 1978.
Basis: CCIR report numbers; dB of margin
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-1002
CLM-1002, Energy Aperture, as of 1981-01.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-543
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