LIDAR – and LED’s – How they Track, Monitor and Kill . . .

LED  Light
Five billion lights in America, and counting . . .
LEDs (light-emitting diodes) are the low-voltage semiconductors providing solid-state lighting ubiquity, network connectivity, and access to power for the Internet of Things (IoT). Unlike analog high-voltage light fixtures, LEDs and digital go together, which is why they pretty much constitute the Internet-connected central nervous system of smart buildings. LEDs have sensors in them that 24/7 sense their

environment, act on the information, then network it. In other words, if you see the LEDs, they see you.[1]
LEDs are perfect for Internet connectivity through Li-Fi technology. By increasing the flicker rate of LEDs,data can be transmitted to specially adapted laptops and electronic devices via the visible spectrum instead of via the currently used radio and microwaves.
LEDs are used to transmit visible light whereas Li-Fi(light fidelity) is a visible light communication system that uses invisible UV and IR light to transmit dataat high speeds between wireless devices. In 2013, 1-watt LED light bulbs connected computers to Internet at 3.25 gigabytes per second (Gbps). PureLiFi
demonstrated the first commercially available Li-Fi system, the Li-1st, at the 2014 Mobile World Congress in Barcelona. 

Whereas Wi-Fi usesradio frequencyto transmit data, Li-Fi uses light, which means Li-Fi can use higherbandwidthand work in areas of electromagnetic interference (aircraft cabins, hospitals, nuclear power plants) while offering higher transmission speeds.

This particular optical wireless communication (OWC) technology uses light from light-emitting diodes (LEDs). Visible light communications (VLC) work by switching the current to the LEDs off and on at a very high rate, too quick to be noticed by the human eye. Although Li-Fi LEDs have to be kept on to transmit data, they can be dimmed to below human visibility while still emitting enough light to carry data. 

Light waves, however, cannot penetrate walls, which means they have a much shorter range than Wi-Fi, though they are more secure from hacking. Direct line of sight is not necessary for Li-Fi to transmit a signal; light reflected off the walls can achieve 70 Mbit/s

Both Wi-Fi and Li-Fi transmit data over the electromagnetic spectrum, but whereas Wi-Fi utilizes radio waves, Li-Fi uses visible light, UV and IR. The Li-Fi market is projected to be worth over $6 billion per year by 2018. The visible light spectrum being 10,000 times larger than the entire radio frequency spectrum, Li-Fi has almost no limitations on capacity. Researchers have reached data rates of over 224 Gbit/s,[15] which was much faster than typical fast broadband in 2013. Li-Fi is expected to be ten times cheaper than Wi-Fi. Short range, low reliability and high installation costs are the potential downsides. 

Bg-Fi is a Li-Fi system consisting of a mobile device app and an IoT (Internet of Things) device with color sensor, microcontroller, and embedded software. Light from the mobile device display communicates to the color sensor on the IoT consumer product, which then converts the light into digital information. LEDs enable the consumer product to communicate synchronously with the mobile device. 

LIDAR 

            Lidar (light detection and ranging) is an optical remote sensing technology using pulsed laser light just as sonar is pulsed sound and radar is pulsed radio waves. By measuring the backscattered light to the target and back, distance can be determined as well as atmospheric density, which is why lidar is used for aerosol loading. Ozone is also measured with a specialized lidar called the airborne UV differential absorption lidar (DIAL).
            Lidar is also used for mapping and measuring chemical compounds and nano-sensors over a wide area (80 km)—airborne laser swath mapping (ALSM), laser altimetry, contour mapping, remote sensing, archaeology, etc. [The remote sensing and imaging open-path Fourier Transform infrared spectrometer (OP-FTIR and I-OP-FTIR) use infrared light to do much the same with computer-assisted tomography (CAT).]


[1]Brian Chemel, “How Intelligent Lighting Is Ushering In the Internet of Buildings.” TechCrunch, December 20, 2015.