vendredi 6 janvier 2017
CYGNSS Hurricane Mission Measures “First Light” Science Data
NASA - CYGNSS Mission logo.
Jan. 6, 2017
NASA’s Cyclone Global Navigation Satellite System (CYGNSS) constellation of eight spacecraft made its “first light” measurements of the ocean surface on Jan. 4, 2017. Measurements were made by one of the eight spacecraft, and mission scientists plan to activate the science instruments on the other seven in the near future. Direct measurements are made of the GPS power reflected by the ocean surface, from which near-surface wind speed can be derived over tropical oceans and, in particular, inside hurricanes.
Image above: This image shows “first light” data from NASA’s CYGNSS mission in the form of a Delay Doppler Map produced by one of the eight spacecraft (FM03) that make up the constellation at 15:48:31 UTC (11:48:31 a.m. EST) on Jan. 4, 2017. The peak in the center of the image represents scattered GPS signal from the ocean surface, from which near-surface wind speed can be derived. Image Credit: NASA.
CYGNSS was launched on Dec. 15, 2016, at 8:37 a.m. EST into a low-inclination, low-Earth orbit over the tropics. The CYGNSS constellation will make frequent and accurate measurements of ocean surface winds in and near a hurricane’s inner core, including regions beneath the eyewall and intense inner rainbands that previously could not be measured from space.
Direct science measurements are displayed as a Delay Doppler Map (DDM), which shows the GPS power reflected by the ocean in the vicinity of the targeted measurement location. One such DDM is shown here, measured by constellation spacecraft FM03 on January 4, 2017, at 11:48:31 a.m. EST/15:48:31 UTC in the South Atlantic Ocean, east of Brazil.
“Our first light DDMs are direct confirmation that the CYGNSS science instrument on FM03 is operating as expected,” said Christopher Ruf, CYGNSS principal investigator at the University of Michigan’s Department of Climate and Space Sciences and Engineering in Ann Arbor. “There are still many steps ahead of us leading to reliable improvements in hurricane forecasts, but this was a critical one and it feels great to have it behind us.”
Image above: Artist's concept of one of the eight Cyclone Global Navigation Satellite System satellites deployed in space above a hurricane. Image Credit: NASA.
CYGNSS is the first of the missions competitively selected through NASA’ Earth Venture Program to launch into orbit. The Earth Venture Program is managed by the Earth System Science Pathfinder (ESSP) Program Office at NASA’s Langley Research Center, Hampton, Virginia. This program focuses on low-cost, science-driven missions to enhance our understanding of the current state of the complex, dynamic Earth system and to enable continual improvement in the prediction of future changes.
The CYGNSS mission is led by the University of Michigan, with the Southwest Research Institute in San Antonio, Texas, leading the engineering development and operation of the constellation. The University of Michigan Climate and Space Sciences and Engineering department leads the science investigation, and the Earth Science Division of NASA’s Science Mission Directorate oversees the mission.
Newly Launched CYGNSS Microsatellites to Shed Light on Hurricane Intensity
For more information about CYGNSS, visit: http://www.nasa.gov/cygnss/
Images (mentioned), Text, Credits: NASA/Joe Atkinson.
Publié par Orbiter.ch à 16:15