Microwave radar monitors sliding slopes: Geodesists research within the Alps

The "Steinlehnen" slope in Northern Tyrol (Austria) began to maneuver in 2003. Rockfalls threatened people, roads and structures. Meanwhile, peace has came back even though the slope is basically "sneaking," Steinlehnen is becoming a fascinating research object for researchers recently.

Professor Andreas Eichhorn from the Geodetic Measurement Systems and Sensors branch within the Department of Civil and Environment Engineering in the Technical College of Darmstadt started the interdisciplinary project KASIP (Understanding-based Security Alarm with Recognized Deformation Predictor) along with the Technical College of Vienna and also the "alpS" research institute the aim ended up being to mix metrological findings from the slope with computer models.

"An incline is greatly complex," states Eichhorn. It can be hard to find out just how a mountain slope consists and just how failing mechanism works at length. Therefore, researchers won't have the ability to depend exclusively on computer-based models to calculate mass actions later on additionally they need efficient and precise surveillance and monitoring systems which are as comprehensive as you possibly can.

To get this done, Eichhorn and the team examined different techniques at Steinlehnen. "Setting up sensors in highly active regions of the mountain is extremely harmful," describes Eichhorn. "I was searching for a technique that, amongst other things, makes non-contact observation possible." Ultimately, one way demonstrated to become particularly appropriate although its fundamental physical principle has been utilized in geodesy for any very long time, it had been not used at all for that monitoring of slopes. This process utilizes a microwave radar from the Department of Physical Geodesy and Satellite Geodesy from the TU Darmstadt (Professor Matthias Becker), that was applied prototypically by Eichhorn's team of Darmstadt researchers.

Here, the whole the surface of an incline is "shot" with microwaves which are deflected in the surface and may then be examined. By evaluating different dimensions, the researchers can document changes of only a couple of millimeters. Accumulations or erosion of rock material, or perhaps the start of a significant landslide, can thus be recorded, Eichhorn states. As opposed to techniques that scan the top with laser light, for instance, microwaves deliver a smaller amount disturbance. "A laser has an excessive amount of noise," states Eichhorn. In her own dissertation, doctorate candidate Sabine R?delsperger developed an assessment technique for interpretation the measured data amongst other things, this causes it to be easy to remove meteorological disturbances and to reach significant three dimensional pictures of the slope.

Throughout the KASIP experiments, the geodesists from Darmstadt, along with their co-workers in the area of geophysics, accomplished many important experience for that better interpretation of observed geophysical phenomena and also the correlation between your weather and also the sliding behavior from the slope. However the research also offers practical benefits, as Eichhorn describes: "Exclusively when it comes to technology, you'll be able to continuously monitor a sizable-scale critical slope in high-resolution. Accelerations -- early indications from the possible sliding of huge public -- could be detected, also it can be determined once the slope stops moving."

Microwave radar products continue to be very costly, however the method already has potential like a good early warning system: "Should you observe critical slopes together, you can dependably determine wherever something is going on,Inch states Eichhorn. "Then less costly measurement systems as well as their sensors might be particularly applied there."

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National Weather Service completes Doppler radar upgrades

April 25, 2013

Dual-pol data shows what type of precipitation is falling based on its shape.

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This week, the National Weather Service completed the dual-polarization technology update in Brownsville, Texas – concluding the 122 NWS radar site upgrades throughout the country. This new advanced technology is helping federal weather forecasters more accurately track, assess and warn the public of approaching high-impact weather.

Dual-polarization is the most significant enhancement made to the nation’s federal weather radar system since Doppler technology was first installed in the early 1990s. Dual-pol radar sends and receives both horizontal and vertical pulses, which produces a much more informative picture of the size and shape of the objects in the sky. This provides meteorologists the ability to distinguish between rain, snow, hail and non-weather items like wildfire smoke plumes, birds and insects. Conventional Doppler radar only has a one-dimensional view making it difficult to tell the type of precipitation or object in the sky.

The radar receiving dish inside the protective cover. Dual-pol is both a hardware and software upgrade to the radar.

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“This achievement is the result of years of research, development and continued investment that’s helping us become a more weather-ready nation,” said Dr. Louis Uccellini, director, NOAA’s National Weather Service. “It is amazing what we can see with dual-pol technology. This game-changing technology has already helped forecasters issue more accurate and timely warnings to the public and has saved lives.”

Dual-pol is credited with providing improved detection of heavy rainfall, which can increase warning time for flash floods. During winter storms, forecasters use dual-pol information to monitor a transition from snow to sleet and freezing rain, which allows for a more accurate forecast. Dual-pol can also spot airborne debris giving forecasters the ability to confirm a tornado on the ground, even in the dark or when hidden by heavy rain. The new technology has also been used to help detect hazards to aircraft, such as volcanic ash plumes, icing conditions and birds.

“I am committed to supporting the National Weather Service’s critical mission of forecasting and warning about severe weather, and supporting the men and women who work every day to fulfill that mission”, said Senator Barbara A. Mikulski, chairwoman of the Appropriations subcommittee that funds NOAA, “We owe it to our communities – to the coastal states that depend on accurate hurricane forecasts, and to the interior states that depend on timely tornado warnings – to make sure our weather offices are fit for duty. These new state-of-the-art radars will ensure our forecasters have the tools and technology they need to protect lives and livelihoods.”

Dual-polarization is the most significant enhancement made to the nation’s Next Generation Weather Radar network, NEXRAD, since Doppler radar was first installed in the early 1990s.

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The National Weather Service has used dual-pol to develop 14 new radar products that have improved the speed, understanding, and accuracy of the information it provides about extreme weather. Forecasters now have more confidence to accurately assess weather events and be more descriptive in weather warnings, which helps improve public response to the warnings.

The nationwide dual-pol upgrade began in Sept. 2011 and the public has been benefiting from the new technology every day since. Here are a few successes:

On Feb. 10, 2013, NWS weather forecasters in Jackson, Miss., used the new radar technology to confirm a powerful tornado (EF-4) was moving across Southern Mississippi’s Lamar County toward the populated city of Hattiesburg. Forecasters warned the public using detailed, descriptive language about the tornado’s size and path, resulting in no fatalities. On the same day, dual-pol information helped the Jackson forecasters recognize thunderstorms with particularly heavy rainfall rates, enabling them to issue flash flood warnings more than an hour before flash flooding started.

Dual-pol technology can also identify non-weather targets such as bugs, bats or debris from a tornado producing damage on the ground.

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On Nov. 7-8, 2012, NWS meteorologists at the Boston forecast office relied on dual-pol radar information to help locate the rain/snow line as a nor’easter traversed the area. During the afternoon and evening, a storm formed across Rhode Island and eastern Massachusetts. Snow fell to the west of the boundary where temperatures dipped into the 30s, while rain fell to the east where temperatures held in the 40s. Using dual-pol information, forecasters were able to accurately track the slow progress of the rain-snow line and provide short term forecasts which helped department of transportation officials focus their snow removal assets and for the media to highlight the hazardous routes to the traveling public. The NWS forecast office in Phoenix relied on dual-pol technology to successfully warn for a very large dust storm that moved across the metro area during the early evening of July 5, 2011. There were widespread reports of near-zero visibility and winds gusting more than 50 mph. Dual-pol radar data estimated this dust storm reached a peak height of at least 5,000 to 6,000 feet, with a leading edge stretching close to 100 miles and traveling at least 150 miles. Forecasters collaborated with emergency management and media partners, providing details on potential impacts as the dust approached from the southeast.  Dust storm warnings described the large size of the dust area and the potential for widespread low visibilities of less than a quarter mile.  Safety tips in the warnings and updating warning statements helped people in the storm's path make fast and smart decisions.

In addition to the 122 NWS-owned radars, the full nationwide radar network includes another 37 radar sites owned by the FAA and Defense Department, which will be completely upgraded to dual-pol technology this summer. NOAA’s NEXRAD radar program is a tri-agency effort with NOAA, the Federal Aviation Administration, and the United States Air Force.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.

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Japan Tsunami Is First Tracked by Radar (LiveScience.com)

Scientists in California got an early look at the tsunami generated by the massive earthquake in Japan as it rippled across the Pacific Ocean.

The March 11 Japan tsunami was picked up by high-frequency radar in California and Japan as it swept toward their coasts, according to U.S. and Japanese scientists. This is the first time a tsunami has been observed by radar, raising the possibility of new early warning systems.

"It could be really useful in areas such as southeast Asia where there are huge areas of shallow continental shelf," said John Largier, an oceanographer and study team member from the University of California, Davis. The continental shelf is the perimeter of a continent that is underwater and gradually descends to the ocean floor.

Largier and his colleagues have been using a high-frequency radar array at their lab to study ocean currents for the last 10 years. Together with collaborators from Hokkaido and Kyoto universities in Japan and San Francisco State University, the researchers used data from radar sites at Bodega Bay and Trinidad, Calif., and two sites in Hokkaido, Japan, to look for the tsunami offshore.

The radar detection is the latest in the string of new ways the Japan earthquake and tsunami were observed.Satellite images found that the tsunami was so powerful that it broke off huge icebergs thousands of miles away in the Antarctic. Scientists also found that the earthquake rattled the planet's upper atmosphere.

In the new study, scientists noticed that the radar picks up not the actual tsunami wave — which is small in height while out at sea — but changes in currents as the wave passes.

The researchers found they could see the Japan tsunamionce it entered shallower coastal waters over the continental shelf. As the waves enter the shallower water, they slow down, increase in height and decrease in wavelength until finally hitting the coast.

The continental shelf off California is quite narrow, and approaches to the coast are already well-monitored by pressure gauges, Largier said. But he said radar detection could be useful, for example, on the East Coast or in Southeast Asia, where there are wide expanses of shallow seas.

The study was published in the August edition of the journal Remote Sensing.

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