What are some ideas to make tethers more noticable in the day, and especially at night?

What are some specific products or product categories that could be used for example?

@Kitepower have lit theirs up:


I believe this is done via photophorescent tether strands

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This is an interesting topic.

Some starting points would be:

a - emitting light
b - reflecting light
c - adding visible elements
d - ground based light
e - kite based light

I think all might be infeasible, in part to the small size of the tether and the nature of seeing things from a distance.

So we should also consider if we can do without, perpaps relying on fixed warnings on maps and in computer systems

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The link @luke gave shows nighttime visibility is not impossible. So then daytime visibility remains - if you choose to fly in the daytime.

Only your point “c” would work in the daytime, and maybe point “b” if it reflected the sun.

Some more brainstorming:

f - bird of prey shapes to scare off birds
g - reflect the sun or shine a powerful light from an element on the kite towards anything flying
h - rapid changes in color, from movement or rotation of the tether
i - additional kites in the air with the only purpose of raising highly visible tethers, maybe demarcating the danger zone

That then has to be a no-fly zone because of pilots flying under visual flight rules?

Worst case scenario: tether is in the clouds. Then the system should be grounded?

I think fog, clouds, twilight etc means that even if you choose light or color to mark the kite and tether, there will always be times when those elements are less visible

Shoot them with Freekin LASERS.
Then you can get good data back from them as well.

I’ve put bike spoke reflectors on the lines of a Daisy I lent to the scouts. They left it tied up permanently for a few days and nights at camp. They tell me that nobody was beheaded by kite lines at that camp.

But do we need to show the lines if they are only short sections between active rigid parts?
Certainly any fast moving rigid wing part can have a RAT onboard gen to power light.

I believe pointing lasers upwards is a no-go for aviation

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Yes. And rain and snow and hail. Fog and wind often exclude each other though. And I think clouds rarely are low enough to be a problem.

j - elastic tethers, to lessen the impact of an impact
k - slow moving tethers, to lessen the impact of an impact

So we now can make the reasonable assumption that an airborne system should be grounded some of the time, in most places where people fly. Let’s try to brainstorm specific solutions that could be used in the 2 best case scenarios: good visibility during the day, and good visibility during the night.

For lighting sakes this may be problematic true!
However, an amount of laser can be pointed skyward safely.
Utilities like LIDAR are common enough now.
Low power room mapping lasers, I don’t don’t see a huge problem with them outdoor, given the separation from a rotor kite 200m to your aircraft. Laser mapping of an expected set of live scenes can be tightly focused.
Whether or not combined laser mapping and reflective patch spotting could be considered bright enough, Well yes, like the lighting rig on Strictly Come Dancing.

If a couplet or set of kites is stricktly bound in a reel dance they could easily target each other with small laser. Attenuation of the laser by cloud / hail / other would be illuminated to nearby traffic.

Lasers aimed at the sky are forbidden by FAA. They alarm pilots. Laser-show pros know this and work accordingly.

“Conspicuity” lighting to FAA spec (“FAA Red”, so many lumens, etc.) every 50ft along any main tether have current FARs (Federal Airspace Regulations). Anyone who can show equivalent function can get a waiver from a local FSDO (flight standards district office). See TACO 1.0 for details-

http://www.energykitesystems.net/CoopIP/TetheredAviationConOps.html

Further reason to light up AWES colorfully is Wubbo’s AWEfest concept, to popularize AWE.

I thought the Roosegaarde show used light-pumped fiber-optic polymer. kPower Austin co-tested electroluminescent kite line for show at Ambient Camping Paint-the-Sky, in shorter section than the Dutch case, but earlier.

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Related:
https://groups.yahoo.com/neo/groups/AirborneWindEnergy/conversations/topics/4351

Selected comments:

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Thanks to TUDelft for the report. Their bird strike event is consistent with broad kite hobby and sport experience, where strikes are fairly common, but birds are generally unharmed. KiteLabs and kPower have also reported seemingly harmless bird strikes.

The reality is that higher-velocity AWES architectures (rigid wings) will pose a far greater risk to birds and bats, but no specific reports yet. AWE professional practice will surely come to include incident reporting, like most wind farms and aviation do. Its known and regretted some stealth ventures have chosen not to report mishaps, under weaker ethics.

We are supposed to self-regulate in aviation R&D, or we become regulated as failures occur.

Didn’t find those yet, or didn’t search yet.

DIY project:

Flying at night has many advantages:

  • If you illuminate the system, you will be visible from very far away.
  • Less activity in birds and so lower chance of collisions with them.
  • There is no UV damage to line and kite. UV damage is the most important factor by far in the longevity of polymer materials out in the sun I think.
  • Some countries do not allow flying at night under visual flying rules.

It also has possible disadvantages:

  • Light pollution.
  • Possibly stricter regulation, maybe or probably overlapping with night visual flying rules.
  • Bats more active and so higher chance of collisions with them.

What are some more advantages and disadvantages of flying during the day or night? Can you elaborate on or correct an advantage or disadvantage I already mentioned?

The advantage of flying an AWES at night is
The sun ain’t shining - people want to charge their e-car at night - solar ain’t working - perfect time to get flying because your kite isn’t going to get any UV damage.


and you can take cool pictures too

The Lidar system used by Waymo cars is being offered for testing in projects. https://waymo.com/lidar
As mentioned previously. Lidar is extensively used already in wind field analysis without problems.
Anyone still harbouring objections that Lidar can be useful without presenting a risk to aviation?

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When the aviation industry will use lidar, they will have to assess the risk and then we’ll have definite answers.
I’d bet there won’t be an issue and one can include lidar in awes.
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Linking two related topics:

There will continue to be Airspace conspicuity standards defined by FAA-ICAO criteria independent of advertising-based conspicuity, which would be harder to validate.