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GPS Tide Gauge Measures Sea Level Change

Using radio signals from satellite navigation systems, Scientists at Chalmers Department of Earth and Space Sciences have developed and tested a Global Navigation Satellite System (GNSS) tide gauge, an instrument that measures the sea level.The GNSS tide gauge uses radio signals from satellites in orbit around the Earth that are part of satellite navigation systems like GPS and Glonass (Russia’s equivalent of GPS).Two antennas, covered by small white radomes, measure signals both directly from the satellites and signals reflected off the sea surface. By analyzing these signals together, the sea level and its variation can be measured, up to 20 times per second.”We measure the sea level using the same radio signals that mobile phones and cars use in their satellite navigation systems,” says researcher Johan Löfgren. “As the satellites pass over the sky, the instrument ‘sees’ their signals – both those that come direct and those that are reflected off the sea surface.” SourceAlso: Learn about Global Positioning System (GPS) Meteorology.

Posted in: Environmental Monitoring, Green Design & Manufacturing, Test & Measurement, Measuring Instruments, RF & Microwave Electronics, Antennas, News

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Unmanned Aircraft Tested as Tool for Measuring Polar Ice Sheets

Scientists studying the behavior of the world's ice sheets — and the future implications of ice sheet behavior for global sealevel rise — may soon have a new airborne tool that will allow radar measurements that previously would have been prohibitively expensive or difficult to carry out with manned aircraft.

Posted in: Environmental Monitoring, Green Design & Manufacturing, Test & Measurement, Measuring Instruments, Monitoring, Aerospace, Aviation, RF & Microwave Electronics, News

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OCULLAR Provides Around-the-Clock Ocean Measurements

A team led at NASA's Goddard Space Flight Center in Greenbelt, Md., has developed an instrument capable of observing ocean color during normal sunlight conditions and under moonlight — a first-ever capability that will allow scientists to monitor the health and chemistry of the planet’s oceans literally around the clock.The prototype Ocean Color Underwater Low Light Advanced Radiometer (OCULLAR) has shown in field testing that it can measure ocean color under low-light conditions across multiple wavelength bands, from the ultraviolet to the near-infrared. In contrast, current remote-sensing instruments can obtain measurements — based on electromagnetic energy emitted by the sun, transmitted through the atmosphere, reflected off Earth’s surface, or upwelled from water masses — only during daylight hours, said Principal Investigator Stan Hooker.Of particular interest to scientists studying ocean color is phytoplankton, the microscopic ocean plants that form the base of the oceanic food web. The tiny plants use sunlight and carbon dioxide to produce organic carbon. This process, called photosynthesis, is possible because plants contain chlorophyll, green-colored compounds that trap the energy from sunlight. Because different types of phytoplankton contain different kinds of chlorophyll, measuring the color of a particular area allows scientists to estimate the amount and general type of phytoplankton there. Since phytoplankton also depend on specific conditions for growth, they frequently become the first to be affected by pollution or some other change in their environment.Until now, however, obtaining these measurements was limited to daylight hours and only during the spring, summer and fall months in the polar regions — a problem Hooker sought to correct with OCULLAR. The successful OCULLAR demonstration leads the way to anticipated commercialization and creates a new capability for oceanographers, climate scientists, and others interested in quantifying, understanding, and monitoring the biological productivity of oceans, coastal areas, and inland waters.SourceAlso: Learn about a Data Assimilation System for Coastal Ocean Prediction.

Posted in: Photonics, Environmental Monitoring, Green Design & Manufacturing, Test & Measurement, Measuring Instruments, Monitoring, News

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NASA Simulator Recreates Space Dust

A team of scientists at NASA's Ames Research Center in Moffett Field, California, has successfully reproduced, on Earth, the processes that occur in the atmosphere of a red giant star and lead to the formation of planet-forming interstellar dust.Using a specialized facility, called the Cosmic Simulation Chamber (COSmIC), scientists now are able to recreate and study dust grains similar to the grains that form in the outer layers of dying stars. Scientists plan to use the dust to gather clues to better understand the composition and the evolution of the universe.In the past, the inability to simulate space conditions in the gaseous state prevented scientists from identifying unknown matter. Because conditions in space are vastly different from conditions on Earth, it is challenging to identify extraterrestrial materials. Thanks to COSmIC, researchers can successfully simulate gas-phase environments similar to interstellar clouds, stellar envelopes, or planetary atmospheres environments by expanding gases using a cold jet spray of argon gas seeded with hydrocarbons that cools down the molecules to temperatures representative of these environments.COSmIC integrates a variety of state-of-the-art instruments to allow scientists to recreate space conditions in the laboratory to form, process, and monitor simulated planetary and interstellar materials. The chamber is the heart of the system. It recreates the extreme conditions that reign in space where interstellar molecules and ions float in a vacuum at densities that are billionths of Earth's atmosphere.SourceAlso: Learn about Coatings for Lunar Dust Removal.

Posted in: Materials, Test & Measurement, Monitoring, Aerospace, News

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An Alternative to Check Fixtures

Discover how the world’s leading manufacturers are using portable CMM’s to eliminate the need for check fixtures – significantly reducing storage, maintenance and rework costs. Additionally, learn how the portable CMM solution yields actionable, quantifiable data that manufacturers can use in a six sigma and/or lean manufacturing environment to improve their products and become more profitable.

Posted in: Test & Measurement, White Papers

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An Introduction to Stress Analysis and Transducer Design Using Strain Gauges

The usual way of assessing structural parts of machines, buildings, vehicles, aircraft, etc. is based on strength of material calculations.

Posted in: Test & Measurement, White Papers

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Wind Tunnel Tests Support Improved Design of B61-12 Bomb

Sandia National Laboratories has finished testing a full-scale mock unit representing the aerodynamic characteristics of the B61-12 gravity bomb in a wind tunnel. The tests on the mock-up were done to establish the configuration that will deliver the necessary spin motion of the bomb during freefall and are an important milestone in the Life Extension Program to deliver a new version of the aging system.

Posted in: Motion Control, Motors & Drives, Test & Measurement, Aerospace, Defense, News

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