Value chain · CLM-0868
Low confidence
The evidence behind this statement is thin, indirect or second-hand. Read it as a lead to check, not as a settled finding.
In plain terms
The beam shape drawn in the 1978 report narrows slightly faster just outside its peak than the antenna design in the same report can produce. The gap is three to four per cent, which is small and near the limit of what a hand-drafted figure can be read to.
The claim as recorded
SRC-085's Figure 18 shows a main lobe falling off 2.7 to 4.3 per cent faster on its skirt than any Gaussian illumination taper produces. The scale-free ratio r(peak/230) / r(peak/23) measures 1.140 to 1.158 on the figure across four candidate x origins, and 1.140 from the figure's own annotated radii of 5.7 km and 5.0 km, against 1.1892 from the model used here of the source's 10-step taper and 1.168 to 1.231 for continuous Gaussians of any depth between 3 and 20 dB.
Evidence behind this: T0-calculation. A scale-free radius ratio is extracted from SRC-085's Figure 18 by pixel measurement across four candidate x origins and compared against the same ratio from the diffraction model used here. Arithmetic performed here; see CALC-086.
Scope and limits
Small, open, and stated as a disagreement rather than a defect in either party. It is one fifth the size of the sidelobe-position disagreement it replaces, and it is at the edge of what a hand-drafted 1978 figure can be read to. The ratio was chosen because it is scale-free: it is immune to the error budget, the projection and the x scale, and needs only the origin - and the disagreement holds across every defensible origin, so it is as origin-robust as the sidelobe-position AGREEMENT is. The error budget pushes the wrong way to explain it: filling the null raises the skirt and would increase the ratio, not reduce it. Figure 18's x origin is itself unresolved to about 4 per cent and no conclusion here depends on resolving it. STRONGER THAN THIS RECORD FIRST ARGUED, per VER-1093, because the annotation route is origin-free: to overturn it one would have to show that the figure's OWN PRINTED RADII are wrong, which is a different and much harder claim than choosing an x origin. The spread is 2.7 to 4.3 per cent, corrected from a stated 3 to 4. One harmless mismatch, recorded because the argument for it was not written down: the figure is a ground plot and the model is beam-normal, which cancels in a ratio along the minor axis where the two coincide and under any uniform stretch - harmless BY ARGUMENT, and the argument now exists. Confidence stays LOW: it is still a hand-drafted 1978 figure.
What it assumes
That Figure 18 is drawn to a consistent radial scale, and that the pattern plotted is the same design point as the annotated radii.
Where it comes from
This is the project's own working, shown in full:
Model, SRC-085 10-step taper: 1.1892. Model, continuous Gaussian at any depth 3 to 20 dB: 1.168 to 1.231. Figure 18 measured at origins 178.17 / 183.40 / 185.42 / 186.00 PDF units: 1.140 / 1.152 / 1.157 / 1.158. Figure 18's own annotations, 5.7 km and 5.0 km: 1.140. Matching the model would need an origin at 195.8, which the same figure's sidelobe level and annotated radii both exclude. THE ANNOTATION ROUTE IS THE PRIMARY SUPPORT AND IT NEEDS NO ORIGIN AT ALL, established by VER-1093. Figure 18's radii are printed IN KILOMETRES and are therefore already referenced to the figure's own origin: 5 km sits at the 1 mW/cm2 level and 5.7 km at 0.1 mW/cm2, with 23 mW/cm2 at the peak, so 5.7/5.0 = 1.1400 exactly and no origin enters it. The pixel route and the 195.8 question are corroboration, not the argument.
Basis: dimensionless ratio of two radii on the main-lobe skirt
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0868
CLM-0868, Energy Aperture, as of 2026-09-06.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-085
- CLM-0013The paper that modern UK studies rely on for the beam figure calls anything below 1 kilowatt per square metre safe, with 230 watts per...CLM-0020The original 1978 design set the beam at 230 watts per square metre in the middle of the receiving site, about one twenty-third of that at...CLM-0023In the 1978 reference design, two limits set the size of the transmitter and the receiving site: how much heat the transmitter can shed...CLM-0039The 1978 report set the figure to protect radio and navigation systems from a disturbed ionosphere, called the number theoretical and...CLM-0045The apparent conflict between 12 and 23 was not an error. The underlying study gave a range, and the figure adopted sits near the top of it.CLM-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...CLM-0137In four major space solar power studies from 1978 to 2007, none put a number on how much of the beam's energy would be lost if the beam...CLM-0138The original 1978 government design for beaming power down from space adds up all the expected energy losses to get 63% overall efficiency...More on the source page.