Value chain · CLM-1090
In plain terms
The programme's two printed tables of how much beam the weather eats do not agree. One has the ionosphere numbers the wrong way round, and its rain and hail figures are a million times too small for the unit printed over them. The other is internally consistent.
The claim as recorded
The two attenuation tables the programme printed for 2.45 against 5.8 GHz disagree. RP-1076 Table III-4, "ATTENUATION LOSSES FOR 5-GIGAWATT SYSTEMS", header "Power loss, W", prints ionosphere 0.25x10^3 at 2.45 GHz and 1x10^3 at 5.8 GHz, neutral atmosphere 90x10^6 and 100x10^6, rain heavy (15 mm/hr over 15 km) 148 and 1800, moderate (5 mm/hr over 10 km) 34 and 405, wet hail 2600 and 4990. CP-2141's "COMPARISON OF 5800 MHz AND 2450 MHz" prints ionosphere 1 kW at 2450 MHz and 0.25 kW at 5800, neutral atmosphere at 60 degrees elevation 90 MW and 100 MW, rain (25 mm/hr over 20 km path in beam) 45 MW and 1.450 GW, hail (1.93 cm stones, 10 km path) dry 0.2 GW and 1.7 GW, wet 2.7 GW and 4.99 GW. The ionosphere columns are reversed between the two; CP-2141's direction is the physical one. RP-1076's rain and hail rows read as megawatts under a header that says watts: 2600 W of wet-hail loss from 5 GW is no loss, and CP-2141 prints 2.7 GW for the same medium.
Evidence behind this: T3-two programme loss tables read from renders and recorded as printed, with a unit reading and a column reversal noted, not adjudicated.
Scope and limits
RECORDED AS PRINTED, NOT ADJUDICATED. The rain cases differ (15 mm/hr over 15 km against 25 mm/hr over 20 km) so no rain row is comparable across the tables; only ionosphere, neutral atmosphere and wet hail are, and of those the ionosphere row conflicts and the neutral atmosphere row agrees. Both ionosphere figures (1 kW, 0.25 kW) are far below the register's own estimate for 5 GW (about 46 kW at 2.45 GHz from CLM-0461's fraction), which is a separate question for a CALC. RP-1076's table cites its ref. 18, not held as such. The unit defect is a dropped exponent in the printed table: under the header "Power loss, W" the first two rows carry x10^3 and x10^6 superscripts and the rain and hail rows carry none (read at the render 2026-09-20), and with x10^6 restored the wet-hail row agrees with CP-2141 to within 4 per cent (2.6 against 2.7 GW); a second print would confirm the superscripts were never set.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
Both pages read from renders at zoom 2.0 and every figure above transcribed from the image. RP-1076 text layer for p.61 runs "0.25~10~ 1x 103" and "148 34 1800 405" in column-major order, which is why the render was needed. The RP-1076 header and occurrence footnotes (heavy rain 9, 3, 3 hr/yr; moderate 45, 85, 10 hr/yr for central/eastern, southern and western US) are on the same page. CP-2141 page carries the printed number 60. Direction check: ionospheric collisional absorption falls as the inverse square of frequency (CLM-0947), and the register's own estimate is 9.2e-6 at 2.45 GHz against 1.6e-6 at 5.8 GHz (CLM-0461), so the 2.45 GHz loss must be the larger, as CP-2141 has it. RP-1076's text on the facing page (p.60 / 31) puts the 2.45 GHz atmospheric loss at "2 percent" or 130 MW, which is consistent with neither table's 90 MW row without the rain rows added.
Basis: W, MW and GW of loss from a 5 GW beam, by medium and frequency
Related records
- Answers question
- QST-017 not published in this release
Cite this
energyaperture.com/c/clm-1090
CLM-1090, Energy Aperture, as of 1980-1981.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-107
- CLM-0033 (low confidence)Apart from a 1981 NASA review that found no evidence for the number and suggested a higher one, nobody was found to have revisited it, and...CLM-0060In 1981 a NASA review panel said the 230 watts per square metre figure rested on an obsolete theory with no experimental support, and made...CLM-0061The experiments were done. They found heating two or three times stronger than normal, not the tenfold effect predicted, no irregularities...CLM-0062By 1981 the theory was being revised to a steeper frequency dependence, which would raise the permitted power density.CLM-0063NASA suggested in 1981 that 550 to 600 watts per square metre might be reasonable, roughly two and a half times the figure still in use...CLM-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...CLM-0160A 1978-81 NASA design study calculated that simply pointing the satellite's structure accurately enough, without any electronic correction...CLM-0420NASA's 1981 report says the experiments found nothing supporting the 23 milliwatt limit, that the measured heating was two or three times...More on the source page.
- Also from SRC-551
- CLM-1088By 1980 the programme remembered its first study as having picked 2.45 GHz. The first study's report says it picked 3.3 GHz. The 2.45 GHz...CLM-1091The people running the programme said 2.45 GHz was sensible and also said, in the same breath, that nobody international had agreed to it...CLM-1408In the late 1970s, US studies sketched receiving stations raised on posts or legs so the ground beneath could still be farmed or built on...