Click on the Layers menu in the bottom right of the radar to select radar options like Current Conditions, Storm Tracks and Feels Like Temps. Also get information on current severe weather watches and warnings in your area. Zoom in to your street or out to your region and view past and futurecast radar.
NASA has released a void-filled version of the Shuttle Radar Topography Mission digital elevation model, known as "SRTM Plus" or SRTM NASA Version 3. SRTM Plus uses SRTM Version 2 (see below) where the radar interferometric method was successful (not void). Most voids are filled with elevation data from the ASTER GDEM2 (Global Digital Elevation Model Version 2). ASTER is a sensor on NASA's Terra satellite that uses stereoscopic imaging to measure elevations via optical parallax where not obscured by clouds. Additional void filling of small areas used the GMTED2010 elevation model compiled by the US Geological Survey. SRTM Plus was produced under NASA's "Making Earth System Data Records for Use in Research Environments" (MEaSUREs) Program.
Engineers and scientists at JPL are currently working on a complete reprocessing of the original SRTM radar data in order to produce an improved near-global digital elevation model (DEM) to be called NASADEM. As with SRTM Plus, this work is funded under NASA's "Making Earth System Data Records for Use in Research Environments" (MEaSUREs) Program. In brief, the expected improvements include (1) fine vertical adjustments within and among individual shuttle data takes via reference to precise ICESat (Ice, Cloud, and land satellite) laser profiles, (2) void reduction via improved radar interferometric processing, (3) use of better fill data in the remaining voids, especially ASTER GDEM3 when available, and (4) improved quality assessments and adjustments. This project is scheduled for completion in 2017, but we expect to release interim products in 2016 and early 2017.
QUIET AFTERNOON: We have a generally cloudy afternoon across Alabama with a few sprinkles on radar... temperatures are in the 70s. The focus is on the severe weather threat tonight; to the west SPC has issued a rare \"high risk\" (level 5\/5) of severe thunderstorms around Memphis and into eastern Arkansas. A significant tornado moved through North Little Rock, Arkansas at mid-afternoon, and a few strong\/violent tornadoes could touch down northwest of Alabama through the evening hours.
Scientists widely use radar to look for things underground on Earth. They use it to study Mars-like glacial regions in the Arctic and Antarctic. Ground-penetrating radar helps us locate land mines; spot underground cables, wires and pipes; and reveal ancient human artifacts and even buried treasure! On Mars, the "buried treasure" may be water ice, which helps scientists understand the possibilities for Martian life and also identifies natural resources for future human explorers.
The Radar Imager for Mars' subsurFAce eXperiment (RIMFAX) is ground-penetrating radar (GPR) instrument selected to fly on the 2020 rover and designed to produce from the surface of Mars, for the first time, high-resolution stratigraphic information about the subsurface of the Red Planet.
Different materials (e.g., dense rock, clay, liquid water, ice, or sand) reflect, absorb, or scatter the radar pulses in distinct ways. RIMFAX assembles the returned radar pulses to construct image-like representations of the subsurface structure. RIMFAX images:
Superman had X-ray vision, but RIMFAX's "superpower" is ground-penetrating radar. RIMFAX can "see" underground and produce images of the hidden layers of geology beneath the Martian surface. It can tell us what those materials are, and whether they hold clues to past environments on Mars, especially those with conditions necessary for supporting life. RIMFAX could also detect water and other resources necessary for future human exploration.
Ground-penetrating radar is at the heart of RIMFAX technology. It provides the ability "to see" underground. Scientists use radar data to produce image-like details of rock and other structures beneath the Martian surface.
"Radar" is an acronym that stands for RAdio Detecting And Ranging. On Earth, familiar types of radar systems detect aircraft in the sky or rain patterns in the atmosphere. Whether looking up at the sky or down inside the Earth, all radar systems essentially work the same way.
The radio waves generated by the RIMFAX transmitter range from 150 to 1200 megahertz. This wavelength ranges from tens of meters to millimeters. Depending on the depth of subsurface penetration desired, the RIMFAX team can adjust the frequency transmitted by the radar from lower (150 megahertz) to higher (1200 megahertz). Lower-frequency radio waves penetrate deeper underground, while higher-frequency waves travel less deeply. The RIMFAX science team can take advantage of this feature of radar signals "to tune" or "to focus" the instrument on deep or shallow terrain of interest. Depending on the depth they want to sample and the size of objects they want "to see" in the radar data, the RIMFAX science team can choose from five different operating modes. A vertical resolution of about 3 to 12 inches (15 to 30 centimeters) in most materials reveals fine layering within rocks and sediments.
The radar energy from RIMFAX is directed downward in pulses. As the rover moves, RIMFAX can collect data every 4 inches (10 centimeters) to build up a subsurface profile. Depending on the properties of the material it encounters, RIMFAX can penetrate from the surface to 30 feet (more than 10 meters).
When the radio waves meet objects in their path, they respond in different ways. Different kinds of rocks, minerals, sediments, water, ice, and brines produce unique radar data. Some materials absorb or partially absorb the radar energy. Others strongly reflect the signal. Still other materials scatter the energy, resulting in a weakened return signal.It depends on their chemical makeup, density, and temperature.
RIMFAX scientists can analyze the radar data from Mars to identify underground structures and materials by their unique radar reflections. They know what the radar signal looks like after it encounters each different type of material. Some materials (e.g., liquid water) strongly reflect the radio signal back to the receiver without changing it very much. Pure water ice is essentially transparent to the radar pulse, which passes straight through. Other materials scatter the signal, much like the way water splashes off a hard surface.
Differences in the speed of the returning signal can also help scientists determine what's underground. For example, radar signals encountering liquid water and saltwater are slower in their return than those passing through pure water ice. These differences in response to the radar signal can be used with other observations to understand the composition of underground materials on Mars.
Geologists have learned much about Earth's past by drilling boreholes ranging in depth from hundreds of feet to several miles below the surface. Deep drilling and coring has allowed scientists to reach geological records of the bombardment of our planet by debris earlier in the solar system's history, and to gather evidence about the tectonic, climate and biological cycles of past eons. With our small robotic landers and rovers, it is not possible to drill very deeply into the surface of Mars. Ground-penetrating radar is the next best thing for learning about what's underground. The data RIMFAX provides fills in a big blank in the study of Mars. It provides a view of the structure and composition of the ancient layers in areas the rover roams. 041b061a72