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Radar and AWES
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One of the many new twists to pending FAA AWE regulation is the identification of AWES as a potential source of radar clutter. Clouds of moving radar targets that obscure and confuse existing airspace radar systems will not be easily approved. This is bad news for flygens, conductive tethers, and conductive airframes (aluminum, carbon fiber, etc). A radar stealth requirement would be a huge economic challenge for these designs. It was already hard to imagine a thousand giant aerobatic E-VTOL kiteplanes to power a city. Polymer-rag and string-based AWES seem increasingly dominant in the near-to-mid term.    ~DaveS    6Dec2011

I do not believe radar is a valid reason for resisting AWE.
The idea that radar has rights, that radar is somehow and end-all-be-all
technology, are silly. Likely radar can be replaced with something less
archaic. Meanwhile, what the radar people have to understand is not that the
world will mold itself around the god of existing radar configurations, but
rather that such positional sensing systems must evolve along with the rest of
civilization to sense what is there. One more reason officialdom can sometimes
be counted on to make progress in any field difficult, rather than helping it
along. Think about it: One day someone noticed you can sense things by bouncing
radio waves. Is it realistic to say we will design all of future civilization
based on how it affects our current bouncing radio wave trick?

If anything, working their systems around AWE systems, assuming any were in the
air to worry about in the first place, which makes the whole question moot
anyway, might help them fine-tune their sensing system so it could not be foiled
by someone flying kites.    ~DougS

Dec. 7, 2011

Few questions:

1. When is a radar imprint wanted?
    Would offshore upper radar footprint be wanted?
    Are there conceptions that would invite FAA to want definite radar imprint?

2. Robust understanding  and catalog of passive-control tactics
without radar imprint.

3. Extensive collection of control via two lines or more lines.
    Line-tension changes for control?
    Oscillations in lines for control?

4. How might a lofted kite-control unit or kite-steering unit be made without a radar imprint?

5. How to be invisible to radar?  
    What constructions are invisible to
    Which constructions are visible to radar?

6. How to test AWES for radar imprint?

7. Just when would an AWES having radar imprint NOT be considered as "cluttering" the radar screen?

Some study:
Section 5. Surveillance Systems                   4-5-1. Radar


  • Pierre,   The SkySails Control Pod is a small radar target with a stealthy shape (no corner reflector surfaces) and would be fairly easy to coat with radar absorbing "blackball" paint. Of course, the parafoil itself is almost invisible to radar naturally, if the cloth sizing does not contain aluminum or other metallic ingredients.

    A complex giant kite-plane is another matter altogether,

  • v
Terms, aspects, notes
  • What about sonar, lidar, sodar, infared, optical detection, ... ?
  • Conspicuity issues?   How will other aircraft see AWES?
  • High-visibility (optical?) surfaces without radar reflection?
  • Tether visibility?
  • Airborne radar systems
  • Clear-air turbulence detection
  • Will radar-absorbent material play in any AWES?