GLOBE Observer vs LEctenna Tester

The GLOBE Observer app enables you to make observations of your environment. GLOBE Observer is the app of the Global Learning and Observations to Benefit the Environment (GLOBE) Program. The GLOBE Program is an international science and education program that provides students and people of all ages worldwide with the opportunity to participate in data collection and the scientific process, and contribute meaningfully to our understanding of the Earth system and global environment. By using the GLOBE Observer app, you contribute scientific data to your community, students and scientists worldwide, including researchers at NASA, NOAA, and other science research institutions. GLOBE Observer allows all users to contribute observations of clouds, mosquito habitats, land cover, and trees. Trained and certified users can also use the app to submit additional environmental measurements from all GLOBE protocols. GLOBE Clouds allows observers to make regular observations of Earth’s cloud cover and compare them to satellite observations. With GLOBE Mosquito Habitat Mapper, users locate mosquito habitats, observe and identify mosquito larvae, and reduce the potential threat of mosquito borne disease. GLOBE Land Cover is designed to allow users to document what is on the land (trees, grass, buildings, etc.). GLOBE Trees asks users to estimate a tree’s height by taking pictures of trees with their device and answering a few questions. Additional capabilities may be added. Visit us at https://www.globe.gov and https://observer.globe.gov.

What is LEctenna Tester and how does it work?    LEctenna is an abbreviation for Light Emitting Diode (LED) Rectifying Antenna which features a fast-switching Schottky diode paired with a standard LED together in parallel (positive to negative), placed in a test tube to isolate the wires. In electrical engineering, putting components in parallel means connecting both of their pairs leads together. Isolation means they are separated from other nearby objects so other electrical effects don’t interfere with your circuit. While simple in its construction, LEctenna acts to rectify incoming radio signals into DC electricity that lights up the LED. This happens because as electromagnetic waves pass through the LEctenna device, they cause the charge distribution to flip between opposite sides of the diodes. Typically, this would create a net-zero voltage across the LED, preventing it from lighting up. But because of the Schottky diode’s fast-switching at 2.4 GHz (the same frequency as Wi-Fi) and low capacitance, this results in clipping that allows for a net positive voltage across the LED, allowing it to light up. And there is where the "magic" comes in. Transmitting continuously Wi-Fi packet from an iPhone to a web server allows the LEctenna to harvest enough energy to light up a bit. One of the most interesting applications the power beaming LEctenna demonstrates is in space-based solar power. Using this wireless power technology, we may someday be able to harvest solar energy in space and beam it down for use on Earth. This would allow us to collect solar power day or night, and in any kind of weather. Sunlight is also brighter in space than anywhere on Earth. This technology could be an incredible option in the future for providing clean energy to power the world.