Clever kids kitty cat PJ's
Channel: James Drissel
Date: 2017-01-16

My granddaughter got these cute kittycat skeleton PJ's a few years ago. I think it was from the Day of the Dead stuff at the local Walmart or Target. We didn't know how clever they were at first. I am sure some kids will enjoy looking at this, and it will not harm them, but this video has a more serious purpose.

One evening I was looking for a pet related odor with a blacklight and discovered that the kitty cat skeleton changes to look like an X-Ray under blacklight. 

This was key to an idea I am still working on for drone based search and rescue for low light situations. In far too many cases a search for a missing person is called off or paused because of poor light. There are already projects to use drones to search an area autonomously, often with the idea of extending the search past the times when humans search teams are efficient. My idea is to add a sensor enhancement that can be almost all software and has minimal hardware, power and weight requirements. 

A little background on the chemistry of modern laundry is needed here. Essentially every normal laundry chemical you buy has optical brighteners in them to offset the yellowing that would otherwise occur due to mineral precipitation that occurs when clothes dry. These chemicals absorb UV light and emit a blueish white glow. This is not normally noticeable, but if you switch a sufficiently powerful UV light on and off you will see that a light colored shirt or sock can really stand out even when it is on a light surface such as snow, ash or sand, even if it is lightly dusted with the stuff it is sitting on. It will literally blink with the UV light. The bones in the PJ's were made of white vinyl without optical brighteners. The vinyl does not absorb water so it it would not yellow and did not need optical brighteners and does not absorb them from the wash water. The grey fabric does have optical brighteners, so in normal light we see white bones on a grey background while under UV we see dark bones on a greenish white background.

Drones almost universally have a color camera onboard. Most of these are almost dead weight in low light conditions, but they are still there because they are built-in to most off-the-shelf drones. These almost-useless cameras can be enhanced to detect almost any clothing.

The idea is that the drones all have a white LED and a near UV LED that cycle on and off. This switching would be synchronized across the drones in the swarm. At the simplest form, which light is on could be embedded in the video stream, either as an overlay, metadata or using the audio tracks. Drones move fast, so cameras with faster frame rates are desirable and generally are being fitted more often. It would make sense to make this system independent of what kind of camera a drone has or what framerate it is set to capture, so my approach is going to be to use a near ultrasonic signal that will be recorded by the drone's build-in mics to encode the light state.

If we have some smarts for this on the drone, then during a flight a drone that gets a big signal can slow down and make more approaches at different angles and/or alert an operator. Upon return to the search base, the videos can be loaded onto a more powerful computer for more detailed analysis, automated or otherwise. 

Feel free to implement this idea for personal, non-profit, government or commercial use, but I would like to be credited in any patent or other publication related to refinements of this idea. I don't want money, I just want lost people to be found. Getting credit for thinking of the idea and a copy of such would just be a nice touch.