Value chain · CLM-0161
In plain terms
Satellite-link observations show that natural disturbances in the upper atmosphere can make a 2.48 GHz radio signal's strength swing by close to 100%; these disturbances are worst near the equator and the poles, and Western Europe is less affected except in rare severe conditions.
The claim as recorded
Robinson, Yeoman and Dhillon (2004) state, in their conclusions and without citing a source for the sentence, that observations on existing satellite-ground links indicate natural amplitude fluctuations of close to 100% may occur on 2.48 GHz signals (with somewhat smaller fluctuation levels on 5.8 GHz); in an earlier section built around a Basu et al. (1988) map of worst-case L-band fading, they describe scintillation as most severe at low-latitude/equatorial (local dusk) and polar/auroral latitudes and enhanced during geomagnetic storms and high sunspot-number periods, while noting that Western Europe lies in the mid-latitude region which is less affected, except under the most severe conditions, which occur rather infrequently.
Evidence behind this: T2, following the citer per METHOD line 33. [NESTED CITATION, recorded 2026-09-06 so it is queryable. This claim states what the CITER says about a work that has NOT been read, and its tier stays at the citer's because the tiers are source CATEGORIES, not a quality scale: one step below T2 lands on T3, which asserts a government or agency report with a published method, and that would be a FALSE statement about the document. A downgrade for nesting would put a wrong description in the tier field to express a doubt that belongs in limits. The tier answers how good the evidence is that the citer says this - first-hand, from a PDF we hold - and limits answers how good the relayed physical claim is.]
Scope and limits
Describes NATURAL scintillation only, a baseline load independent of the SPS beam itself; does not address any additional beam-induced enhancement of scintillation, which the same review states remains uncertain. "Close to 100%" is the review's statement of observed natural fluctuation, not a typical value; the review ties severity to region and conditions in a separate section (PDF p.10).
What it assumes
The satellite-ground link observations the review relies on at PDF p.23 are representative of natural-scintillation behaviour at this frequency; the review names no source for that sentence, and Basu et al. (1988) is cited only for the L-band fading map (Figure 4, PDF p.10), not re-verified against Basu et al.'s own paper.
Where it comes from
Robinson, Yeoman and Dhillon (2004), PDF p.23 (printed p.19), conclusions, no citation attached: "Observations already carried out on existing satellite-ground links indicate that natural amplitude fluctuations of close to 100% may occur on 2.48 GHz signals, with somewhat smaller fluctuation levels on 5.8 GHz." PDF p.10 (printed p.6): "the most severe scintillation effects occur in the low-latitude regions around dusk and in the polar regions"; "Western Europe lies in the mid-latitude region which is less affected by scintillation problems, except under the most severe conditions, which occur rather infrequently"; for a 2.48 GHz SPS beam, "amplitude variations of up to 10 dB on time scales of seconds"; Basu et al. (1988) is cited only as the source of Figure 4, "Global distribution of worst case amplitude fading levels at L-band frequencies".
Basis: amplitude scintillation, percent, at 2.48 GHz
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0161
CLM-0161, Energy Aperture, as of 2004 (citing 1988 measured statistics).
Connected records
Other published records linked to this one. A list, not a judgement.
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