Bright Ideas — NASA Sends Space Coms With Lasers, Lidar Reveals Hidden Mesoamerican Ruins
By Abby Proch, former editor
Until now, radio frequency (RF) communications have been the primary way NASA engineers have transmitted data from space back down to Earth. Starting this fall, NASA’s Laser Communications Relay Demonstration (LCRD) will debut laser communications from its high-altitude ground stations in California and Hawaii, according to Phys.org. NASA chose each based on their complimenting weather patterns. Typically, if clouds obscure space above the Optical Ground Station (OGS) in California, then the OGS 2 in Hawaii will have clear skies. At roughly 10,000 feet in altitude, the OGS 2 sits above most atmospheric disturbances (like clouds and dust) that could impact transmission.
Regardless, NASA engineers still use an adaptive optics system to measure any distortion in the electromagnetic signal sent from a spacecraft. If they detect any aberrations, they can respond by sending the signal through a deformable mirror to clarify the signal. The first two years of the LCRD will focus on testing and simulation until the project becomes mission ready.
In lidar news, researchers studying publicly available lidar data have discovered 478 separate sites of Mesoamerican ruins. According to a report from Business Insider and research published in Nature magazine, researchers used data collected from 2017 to 2019 by the Mexican government to identify hidden Olmec and Mayan ruins hidden under tree cover. The team identified the ruins in the lidar-produced 3D maps and then visited many in person to get a closer look. According to the report, lidar can only zoom to about 16 feet scale whereas archaeologists prefer specificity down to about three feet. Researchers believe that these findings also indicate a design influence between the Olmec and Maya civilizations.
Sustainability is all the buzz. Also synonymous with buzz is Apple. Last week, the Sustainable Semiconductor Technologies and Systems (SSTS) research group announced tech giant Apple is its first member, according to VentureBeat. SSTS intends to bring awareness to the environmental impacts of chip production and have influence into its partners' early-stage production choices. According to SSTS, semiconductor chip production accounts for roughly 30% of a mobile device’s carbon footprint. Close to 75% of the device’s footprint is attributed to its entire fabrication, according to the group.
In imaging news, researchers think they’ve found a cheaper, easier, and more accurate medical imaging method that oversteps the clunkiness of tomography, according to a press release from UC Davis. Constructing images from PET and CT scans requires the timely mathematical process of tomography because existing imaging detectors just aren’t fast enough to capture the point at which two annihilation photons form (the result of radioactive isotype interacting with electronics within tissue).
However, with their new technique, researchers instead detect Cherenkov photons and then use a convolutional neural network to provide timing estimation, according to their paper published in Nature. Researchers can pinpoint those annihilation photons within an average of 32 picoseconds and determine their location within 4.8 mm, meaning the results appear in real time and require no postprocessing. What’s more, this method requires a lower radiation dose and can even produce higher quality images.
In other medical imaging news, several researchers are exploring how optical imaging techniques could replace dental X-rays, which carry a risk (albeit low) related to radiation exposure. In an article published in Nature, researchers share their ideas for improving oral healthcare, including a method in which an LED light and camera combo, after a patient swishes around a special mouthwash, would capture signs of decay and present that information via a cell phone app to the patient’s dentist. In other techniques, researchers are also exploring the use of near-IR to create 3D images of teeth to locate cracks and decay long before an X-ray can.