Author Topic: Radar reflective gilet  (Read 2273 times)

Tim Hall

  • I want to eat the fleeting shade of your lashes
Radar reflective gilet
« on: September 11, 2019, 09:29:51 pm »
Would it be ever so wrong to fashion a gilet type garment using a space blanket and velcro so as to increase the radar cross section of the average cyclist and thus increase the chances of triggering a speed camera?

The facts that (a) there's a handily placed speed camera on the hill down to Brighton, (2) there's a Friday Night Ride going past it this weekend and (iii)  I'm going on the ride are all mere coincidences.

(Did I ever tell you of my plans to make a speed camera chaff rocket by repacking a party popper with strips of tin foul?).
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

LittleWheelsandBig

  • Whimsy Rider
Re: Radar reflective gilet
« Reply #1 on: September 11, 2019, 09:42:39 pm »
It might be more efficient to fashion a corner radar reflector and mount it to your handlebars or whatever. Otherwise the wrong body position might create a radar-stealthy cyclist.
Wheel meet again, don't know where, don't know when...

IanN

  • Voon
Re: Radar reflective gilet
« Reply #2 on: September 11, 2019, 09:46:22 pm »
Or get a £20 compact radar reflector for a RIB and mount it to your rack...

https://www.marinescene.co.uk/product/1835/tube-type-radar-reflector-powerboat-version

Re: Radar reflective gilet
« Reply #3 on: September 11, 2019, 09:48:32 pm »


(Did I ever tell you of my plans to make a speed camera chaff rocket by repacking a party popper with strips of tin foul?).

Did you chicken out?

Kim

  • Timelord
Re: Radar reflective gilet
« Reply #4 on: September 11, 2019, 10:53:05 pm »
The Brighton speed camera detects recumbents just fine (DAHIKT), so an average cyclist shouldn't be a problem, unless employing carbon bling stealth bomber tactics.
Careful, Kim. Your sarcasm's showing...

Re: Radar reflective gilet
« Reply #5 on: September 11, 2019, 10:55:33 pm »
A speed camera (can't remember where - Wisbech?) was picking us up on the last FNRTTC...
If it ain't broke, fix it 'til it is...

Kim

  • Timelord
Re: Radar reflective gilet
« Reply #6 on: September 11, 2019, 10:59:38 pm »
A speed camera (can't remember where - Wisbech?) was picking us up on the last FNRTTC...

Did I miss an Opportunity?

That said, even on the Red Baron, I'd struggle to exceed 33mph on the flat for more than a few seconds.
Careful, Kim. Your sarcasm's showing...

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Radar reflective gilet
« Reply #7 on: September 11, 2019, 11:00:21 pm »


(Did I ever tell you of my plans to make a speed camera chaff rocket by repacking a party popper with strips of tin foul?).

Did you chicken out?
Curse these stubby pheasant fingers.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Radar reflective gilet
« Reply #8 on: September 11, 2019, 11:02:23 pm »
It might be more efficient to fashion a corner radar reflector and mount it to your handlebars or whatever. Otherwise the wrong body position might create a radar-stealthy cyclist.
The camera in question detects the rear of the passing vehicle, so I'd need to hang it off my saddle.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Radar reflective gilet
« Reply #9 on: September 11, 2019, 11:05:25 pm »
Or get a £20 compact radar reflector for a RIB and mount it to your rack...

https://www.marinescene.co.uk/product/1835/tube-type-radar-reflector-powerboat-version
I used to sell navigation buoys, as you do, so have a passing familiarity with those sort of gadgets. That one doesn't look very good. In a fit of enthusiasm, I've downloaded a Qinetiq report into radar reflectors, which confirms my suspicions.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Re: Radar reflective gilet
« Reply #10 on: September 11, 2019, 11:06:39 pm »
I set off a 30 mph speed camera on my Brompton tonight. I can now rest happy.
If you don’t make time for exercise now, sooner or later you’ll need to make time for ill health.

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Radar reflective gilet
« Reply #11 on: September 11, 2019, 11:08:15 pm »
The Brighton speed camera detects recumbents just fine (DAHIKT), so an average cyclist shouldn't be a problem, unless employing carbon bling stealth bomber tactics.
Steel frame, 36 spoke 3 cross wheels, as God intended.

I've set it off before, but I was riding next to Adrian, so our combined RCS may have been a factor.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Kim

  • Timelord
Re: Radar reflective gilet
« Reply #12 on: September 11, 2019, 11:20:38 pm »
Or get a £20 compact radar reflector for a RIB and mount it to your rack...

https://www.marinescene.co.uk/product/1835/tube-type-radar-reflector-powerboat-version
I used to sell navigation buoys, as you do, so have a passing familiarity with those sort of gadgets. That one doesn't look very good. In a fit of enthusiasm, I've downloaded a Qinetiq report into radar reflectors, which confirms my suspicions.

Looks a bit on the small side for S-band?  Does marine radar use S-band?  I'm guessing...

ETA: According to a speed-camara-detectorist site, Gatsos use K-band radar.  But a small target is still a small target, and like the traffic lights, it's probably tuned for cars.
Careful, Kim. Your sarcasm's showing...

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Radar reflective gilet
« Reply #13 on: September 11, 2019, 11:27:35 pm »
Or get a £20 compact radar reflector for a RIB and mount it to your rack...

https://www.marinescene.co.uk/product/1835/tube-type-radar-reflector-powerboat-version
I used to sell navigation buoys, as you do, so have a passing familiarity with those sort of gadgets. That one doesn't look very good. In a fit of enthusiasm, I've downloaded a Qinetiq report into radar reflectors, which confirms my suspicions.

Looks a bit on the small side for S-band?  Does marine radar use S-band?  I'm guessing...

ETA: According to a speed-camara-detectorist site, Gatsos use K-band radar.  But a small target is still a small target, and like the traffic lights, it's probably tuned for cars.
All merchant vessels above x size must carry X band. Bigger ones will have S band too. Thus passive reflectors are designed to work with X band.

I couldn't find the Gatso band due to poor Google fu, so thanks for that. Hmm, will an X band passive reflector do anything with K band?
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Kim

  • Timelord
Re: Radar reflective gilet
« Reply #14 on: September 11, 2019, 11:31:42 pm »
I expect so, a corner reflector still works if it's much bigger than the wavelength (consider BS6102 bicycle reflectors, where the cubes are a couple of mm across).
Careful, Kim. Your sarcasm's showing...

Kim

  • Timelord
Re: Radar reflective gilet
« Reply #15 on: September 11, 2019, 11:40:49 pm »
Further thought, speed camera chaff devices are probably available off the shelf from Le Maitre's craft herpes glitter range.

(Can you fire a pyro with the current from a hub dynamo?  Paging Big Clive.  Big Clive to the PINK courtesy phone please...)
Careful, Kim. Your sarcasm's showing...

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Radar reflective gilet
« Reply #16 on: September 12, 2019, 12:07:19 am »
Wiki says Ku band is used, 12-18GHz, so a wave length of 2.5cm to 1.67cm. Half a wavelength is therefore 1.25cm to 0.8cm, which is a bit bigger than your standard glitter.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Kim

  • Timelord
Re: Radar reflective gilet
« Reply #17 on: September 12, 2019, 12:11:12 am »
I dunno, looks about right...

<a href="http://www.youtube.com/v/b1wXzLDW4Tw&rel=1" target="_blank">http://www.youtube.com/v/b1wXzLDW4Tw&rel=1</a>
https://youtu.be/b1wXzLDW4Tw


Here you go, Ku-band chaff:  https://www.lemaitreltd.com/products/special-effects/special-effects/glitter-confetti-streamers/
Quote
Glitter pieces measure approximately 20mm x 55mm


And a CO2 cartridge powered launching device:
https://www.lemaitreltd.com/products/special-effects/special-effects/pocket-air-cannon/
Careful, Kim. Your sarcasm's showing...

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Radar reflective gilet
« Reply #18 on: September 12, 2019, 12:15:27 am »
Ooh. File that under "what could possibly go wrong? "
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

T42

  • Tea tank
Re: Radar reflective gilet
« Reply #19 on: September 12, 2019, 08:11:16 am »
A good bunch of riders can trigger a speed camera. Our 25-strong Audax pack once triggered one on a stretch limited to 90 kph.

I'd love to have seen the picture.
I've dusted all those old bottles and set them up straight.

quixoticgeek

  • Mostly Harmless
Re: Radar reflective gilet
« Reply #20 on: September 12, 2019, 12:29:56 pm »

Note to self, check darwin award site on Monday... :p

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

T42

  • Tea tank
Re: Radar reflective gilet
« Reply #21 on: September 12, 2019, 01:37:10 pm »
Alas, according to the GPX we were only doing about 25 kph.  I think the poor darling got confused by all those shiny spokes.
I've dusted all those old bottles and set them up straight.

Re: Radar reflective gilet
« Reply #22 on: September 12, 2019, 04:39:14 pm »
Would chaff work? I can see it rapidly decelerating from air resistance. I would have thought a fixed reflector would work better...
ETA: it would look super cool though...

Re: Radar reflective gilet
« Reply #23 on: September 12, 2019, 08:22:55 pm »
Further thought, speed camera chaff devices are probably available off the shelf from Le Maitre's craft herpes glitter range.

(Can you fire a pyro with the current from a hub dynamo?  Paging Big Clive.  Big Clive to the PINK courtesy phone please...)
You'd probably need to chuck a capacitor into that one to ensure there was a big enough kick. That used to be my line but for the life of me I can't remember the Vs or As required to set a puffer off.
Rust never sleeps

Re: Radar reflective gilet
« Reply #24 on: September 12, 2019, 08:25:00 pm »
Or get a £20 compact radar reflector for a RIB and mount it to your rack...

https://www.marinescene.co.uk/product/1835/tube-type-radar-reflector-powerboat-version
Those tube reflectors are, I believe, quite sensitive to orientation. When applied to the mast of a sailing yacht they apparently become invisible in a big enough breeze that results in the boat heeling more than a bit.
Rust never sleeps