The joint DGIST–ROKNA research team developed an extrapolation-based Doppler resolution enhancement algorithm for frequency modulated continuous wave radars. This technology improves radar system performance on various intelligent unmanned platforms without additional complex computations or hardware.
Researchers studied the acoustic features Japanese horseshoe bats sense when perceiving moving objects, finding that Doppler shifts, not echo delays, act as a cue. This discovery deepens our understanding of acoustic sensing in nature and has potential applications for next-generation ultrasonic sensors.
Researchers used the NASA Exoplanet Archive and planetary system simulations to find that a drift rate of 53 nHz is sufficient in 99% of known-exoplanet cases. This threshold drops to 0.44 nHz for stars without known planets, reducing computing time and boosting efficiency for future SETI campaigns.
Researchers have developed an integrated THz vortex beam emitter to detect rotating targets with remarkable precision. The system uses spiraling electromagnetic waves with orbital angular momentum to accurately measure the speed of a rotating object, with a maximum margin of error of just around 2 percent.
Researchers at KAUST have developed acoustic tweezers that use spinning sound waves to manipulate ultrasmall objects with precision. This technology has the potential to enable precise control of submillimeter objects in opaque media, such as soft biological tissues.
Researchers create a graphene transistor that produces sonic boom and Doppler-shifted sound waves, offering new insights into this material's potential for nanoscale electronic technologies. The study also discovers a quantum mechanical analogue of the Doppler effect and the Landau velocity effect.
Researchers at NIST demonstrate a faster and more accurate way to calibrate microphones using lasers. The new technique surpasses the current industry standard, offering potential for commercial applications in industries like factories and power plants.
The study demonstrates a stable time-frequency transfer via a high-orbit satellite-ground link, enabling potential performance of optical atomic clocks and intercontinental comparisons. The researchers achieved an instability of 4E-18 at 3,000 s with their dual-comb linear optical sampling method.
Researchers developed a new approach to sound location using bat-inspired technology, outperforming human ears. The system uses a single frequency and receiver, creating Doppler shift signatures that are interpretable with machine learning algorithms.
The Acoustical Society of America will hold its 179th meeting entirely online from December 7-11, bringing together interdisciplinary groups of scientists to discuss their latest research. The conference includes sessions on COVID-19, sound and smell, and more.
Researchers have discovered a memory effect that dramatically alters the Doppler wave signature in scattered waves. This effect, which appears in both relativistic and classical regimes, is influenced by memories of prior wave interactions, resulting in asymmetric peaks in the scattered spectrum.
Bat species use self-generated Doppler shifts to detect prey motions and navigate, revealing new principles for sensory systems. The study found that pinna motion parallel to echo propagation maximizes Doppler shift, providing information on echo source direction.
The first real image of a black hole, obtained by EHT telescopes, confirms the predictions made in Jean-Pierre Luminet's 1979 simulation. The image shows an extraordinary accuracy, with characteristics such as the Einstein effect and Doppler shift clearly visible.
Researchers found that male hummingbirds twist half their tails to aim sound at females, minimizing the Doppler shift effect. This strategic acoustic control allows males to convey speed and agility without revealing their true velocity.
Researchers develop an iterative simulation model that accurately predicts changes to line shape in strong plasma turbulence, providing a system for assessing plasma turbulence. The study finds that the width of hydrogen lines increases in presence of strong turbulence, with oscillating waves at plasma frequency.
Father Christmas can deliver presents without being seen by using special relativity theory devised by Albert Einstein. At high speeds, he shrinks in the direction of travel, allowing him to fit down chimneys.
A team of researchers has successfully demonstrated the synchronization of optical clocks across a low-lying, strongly turbulent, 12-km horizontal air path using a frequency comb. They achieved femtosecond-level clock synchronization by measuring the arrival time of pulses at each site and correcting for the finite speed of light.
Researchers at Disney have developed a system that uses battery-free RFID tags to detect how people interact with everyday objects. The IDSense system can track multiple objects simultaneously and infer movement patterns with high accuracy, opening up new possibilities for interactive play, smart homes, and consumer behavior analysis.
Researchers used transgenic zebrafish and multidimensional time-lapse microscopy to visualize gene expression waves and segment formation. They found that the timing of segmentation is influenced by a Doppler effect caused by shortening embryonic tissue, which modulates the wave profile.
A new study suggests that our experiences of space and time have more in common than previously thought, with people perceiving the future as closer to the present. The researchers found that a temporal Doppler effect occurs when movement through space is toward the future, making it feel closer to the present.
A team of physicists evaluated the UK's caesium fountain clock, achieving an unprecedented level of accuracy. The new method improved uncertainties in Doppler shifts and microwave-lensing frequency shift, reducing errors to 2.3 × 10^-16.
Researchers at Oregon State University have experimentally confirmed the presence of the rotational Doppler effect in individual molecules for the first time. The finding has implications for understanding molecular spectroscopy and high-energy electron studies.
Researchers found that blue whales align their pitch with a common value, enabling them to detect tiny shifts in calls. The study analyzed 4,378 recordings of blue whale songs and observed a remarkably small variation in pitch.
Researchers have discovered the inverse Doppler effect, a phenomenon where electromagnetic waves compress and expand, leading to new advances in optics and communications equipment. This discovery challenges the basic laws of nature and could lead to breakthroughs in material engineering.
Purdue researchers have developed a new method for measuring the velocity of moving objects using lasers and semiconductors. By using an electronic strobe to make light appear to stand still, they can capture cleaner signals from moving objects, resulting in more accurate measurements of speed.