I'm surprised that auto LED headlights don't already broadcast their vehicle VIN# (maybe they do?). Apparently, one of the countries in the Middle East is now requiring some sort of RFID IFF for automobiles. Sure makes the CIA drone program a lot more accurate... I've heard that Disney is starting to replace some of its nighttime *fireworks* displays with *LED drone fleets* displays. I would imagine that some of these temporal streaks could be useful for these drone displays. At the last several CES's (Consumer Electronics Shows), I talked with vendors making bicycle LED displays, and none of them were very imaginative. I did see a T-shirt with a bit-mapped display, but it *wasn't programmable* !! What weren't they thinking? How come I still can't buy a T-shirt with a bitmapped display on it? -- it might be great for political protests, etc. It might be fun to hack the news cameras by synchronizing the T-shirt display with a GPS-derived 60Hz signal; with proper synchronization, it might be possible to have the TV news cameras pick up completely different content from that perceived by human observers! I seem to recall that someone at MIT had developed an LED display for bicycle spokes that was time-multiplexed in such a way as to provide a full circular bit-mapped display -- kinda like those WWII radar displays. At 01:28 AM 4/10/2018, Bill Gosper wrote:
It should also be possible to Morse-code messages by rapidly blinking LED auto taillights to leave dotted and dashed afterstreaks, if you know how to look.