Value chain · CLM-1408
In plain terms
In the late 1970s, US studies sketched receiving stations raised on posts or legs so the ground beneath could still be farmed or built on. They noted a trade-off: panels close to the ground are easier to reach for repairs.
The claim as recorded
Raised rectennas, with land usable underneath, were sketched in the US programme of 1977-80. JPL's 1977 microwave impacts report draws "Rectenna configurations for dual land use" (Fig. 3-3): rows of panels on posts, and flat panels raised on legs, with ground cover drawn beneath both. It says "Shared or multiple land use is feasible for certain enterprises both within the rectenna field and in the personnel exclusionary zone or guard ring". A 1980 NASA workshop paper shows "Potential Rectenna Configurations" (Fig. 1), ground-located and elevated, non-concentrating and concentrating, and says "If desired, the land underneath the rectenna may be used for factories or intensive agriculture." A December 1980 working paper on the military implications of the SPS, by Science Applications, Inc. for a DOE contractor, describing the reference rectenna, says the panels should be as low as possible for access, but that "for alternate land use beneath the rectenna, it would be advantageous to elevate the panels several meters above the ground".
Evidence behind this: Three DOE/NASA-programme reports of 1977-80 (JPL, a DOE-programme working paper on military implications that describes the reference rectenna, a NASA workshop paper); concept sketches and design remarks, not engineered or costed raised designs.
Scope and limits
NO HEIGHT IS STATED BEYOND "SEVERAL METERS"; none of the three gives a clearance, a column spacing or a cost for the raised form (CLM-1409 has the only costing held). The figures are sketches. The 1978 reference design kept the panels low: CLM-1102 has rows about 4 m apart with 6 m roads, and SRC-534 PDF 54 has the ellipse cleared and graded. None of these sources measured crops or animals under a rectenna.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF 68 [3-7], caption, raw: "Rectenna configurations for dual land use"; the drawing (render read): (a) inclined panels in rows on posts, (b) flat panels on legs, with vegetation marks beneath both. SRC-450 PDF 75 [3-14], raw: "Shared or multiple land use is feasible for certain enterprises both within the rectenna field and in the personnel exclusionary zone or guard ring." SRC-551 PDF 295 [285], render read: "If desired, the land underneath the rectenna may be used for factories or intensive agriculture."; Figure 1, "Potential Rectenna Configurations", panels labelled NON-CONCENTRATING, CONCENTRATING, GROUND LOCATION and ELEVATED. SRC-542 PDF 39 [2-12], raw: "For ease of access, the panels should be as low as possible; for alternate land use beneath the rectenna, it would be advantageous to elevate the panels several meters above the ground."
Basis: rectenna configurations (ground-mounted or elevated); land use beneath
Related records
- Answers question
- QST-007 not published in this release
Cite this
energyaperture.com/c/clm-1408
CLM-1408, Energy Aperture, as of 1980.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-450
- CLM-0949There is a standard international curve describing how quickly an antenna's stray radiation should fall away off-axis. The SPS pattern...CLM-0950A solar power satellite in geostationary orbit cannot make its beam any tighter than its design figure, because it is too far away to focus...CLM-0951The usual way to stop a strong transmitter interfering with other radio users is to smear its power across a wide band. For a solar power...CLM-0952A solar power satellite would have to stay below published interference limits, and the limits differ by who is being protected. Microwave...CLM-0969If the tubes are only 70 per cent efficient, the transmitter's own face is not big enough to get rid of the heat they make, even spread...CLM-1413A 1977 NASA-funded report says the metal mesh behind a receiving station's antennas can be about three-quarters open to light while letting...
- Also from SRC-542
- CLM-1039The programme's own military studies did not treat the beam itself as a real weapon. The 1980 study said one captured beam would carry...CLM-1040The programme's first military study said the satellite could not be fully protected; its second said it was no softer a target than a...
- 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-1090The 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...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...