20140320

Geographers create 'easy button' to calculate river flows from space

Los Angeles CA (SPX) Mar 19, 2014


UCLA geography chair Laurence C. Smith has a long running field project in Greenland, where he's trying to measure the amount of water flowing from the country's melting ice sheet.
The frustrated attempts of a UCLA graduate student to quantify the amount of water draining from Greenland's melting ice sheet led him to devise a new way to measure river flows from outer space, he and his professor report in a new study.
The new approach relies exclusively on the measurements of a river's width over time, which can be obtained from freely available satellite imagery.
Currently, hydrologists calculate a river's discharge - the volume of water running through it at any given time - by taking a series of measurements on the ground, including not just the river's width but also its depth at multiple points and the velocity of its flows. Politics, financial considerations and terrain often stand in the way of obtaining such measurements.
"Our new method doesn't require access to the country or getting in the river to safely take measurements in the field," said Colin Gleason, lead author of the study and a doctoral student in geography in UCLA's College of Letters and Science. "As long as we can get multiple pictures of a river and apply this method to them, we can tell you how much water was flowing in the river at the time the images were taken."

Thermal vision: Graphene light detector first to span infrared spectrum

Ann Arbor MI (SPX) Mar 20, 2014


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The first room-temperature light detector that can sense the full infrared spectrum has the potential to put heat vision technology into a contact lens. Unlike comparable mid- and far-infrared detectors currently on the market, the detector developed by University of Michigan engineering researchers doesn't need bulky cooling equipment to work.
"We can make the entire design super-thin," said Zhaohui Zhong, assistant professor of electrical engineering and computer science. "It can be stacked on a contact lens or integrated with a cell phone."
Infrared light starts at wavelengths just longer than those of visible red light and stretches to wavelengths up to a millimeter long. Infrared vision may be best known for spotting people and animals in the dark and heat leaks in houses, but it can also help doctors monitor blood flow, identify chemicals in the environment and allow art historians to see Paul Gauguin's sketches under layers of paint.
Unlike the visible spectrum, which conventional cameras capture with a single chip, infrared imaging requires a combination of technologies to see near-, mid- and far-infrared radiation all at once. Still more challenging, the mid-infrared and far-infrared sensors typically need to be at very cold temperatures.
Graphene, a single layer of carbon atoms, could sense the whole infrared spectrum-plus visible and ultraviolet light. But until now, it hasn't been viable for infrared detection because it can't capture enough light to generate a detectable electrical signal. With one-atom thickness, it only absorbs about 2.3 percent of the light that hits it. If the light can't produce an electrical signal, graphene can't be used as a sensor.
"The challenge for the current generation of graphene-based detectors is that their sensitivity is typically very poor," Zhong said. "It's a hundred to a thousand times lower than what a commercial device would require."

20140213

High resolution, digital bathymetry now available off-the-shelf

Gilching, Germany (SPX) Feb 05, 2014


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Industry leading aquatic earth observation company EOMAP has launched an off-the-shelf bathymetry product line which will transform the uptake and uses of digital bathymetry data. This world first service makes high-resolution, satellite-derived bathymetry available through online portals and its business partners.
Dr. Thomas Heege, CEO, comments that "satellite-derived bathymetry (SDB) technology has matured to a robust and cost effective solution for mapping shallow water bathymetry, especially at high spatial resolutions".
Indeed, Shell Petroleum recently announced at the IPTC conference cost savings of more than 1 M USD when using EOMAP solutions instead of the previous methods, for mapping a 740 sq km area off the coast of Qatar.