doppler-shifted frequency
11Twin paradox — In physics, the twin paradox is a thought experiment in special relativity, in which a twin makes a journey into space in a high speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth. This result… …
12spectroscopy — spectroscopist /spek tros keuh pist/, n. /spek tros keuh pee, spek treuh skoh pee/, n. the science that deals with the use of the spectroscope and with spectrum analysis. [1865 70; SPECTRO + SCOPY] * * * Branch of analysis devoted to identifying… …
13History of radar — The history of radar starts with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell s seminal work on electromagnetism.… …
14Animal echolocation — Echolocation, also called biosonar, is the biological sonar used by several animals such as dolphins, shrews, most bats, and most whales. The term was coined by Donald Griffin, who was the first to conclusively demonstrate its existence in bats.… …
15Atomic line filter — A potassium Faraday filter designed, built and photographed by Jonas Hedin for making daytime LIDAR measurements at Arecibo Observatory.[1] An atomic line filter (ALF) is an advanced optical band pass filter used in the physical sciences for… …
16Flow measurement — is the quantification of bulk fluid movement. Flow can be measured in a variety of ways. Positive displacement flow meters acumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow. Other flow… …
17Medical ultrasonography — This article is about using ultrasound to image the human body. For imaging of animals in research, see Preclinical imaging. Sonography redirects here. For the tactile alphabet called sonography , see Night writing. Medical ultrasonography… …
18Optical coherence tomography — Intervention Optical Coherence Tomography (OCT) image of a sarcoma MeSH …
19Sagnac effect — The Sagnac effect (also called Sagnac Interference), named after French physicist Georges Sagnac, is a phenomenon encountered in interferometry that is elicited by rotation. The Sagnac effect manifests itself in a setup called ring interferometry …
20Chirp — For other uses, see Chirp (disambiguation). A chirp is a signal in which the frequency increases ( up chirp ) or decreases ( down chirp ) with time. In some sources, the term chirp is used interchangeably with sweep signal.[1] It is commonly used …
