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QuikSCAT replacement funded
In November 2009, one of the greatest success stories in the history of satellite meteorology came to an end when the venerable QuikSCAT satellite failed. Launched in 1999, the QuikSCAT satellite became one of the most useful and controversial meteorological satellites ever to orbit the Earth.
It carried a scatterometer--a radar instrument that can measure near-surface wind speed and direction over the ocean. Forecasters world-wide came to rely on QuikSCAT wind data to issue timely warnings and make accurate forecasts of tropical and extratropical storms, wave heights, sea ice, aviation weather, iceberg movement, coral bleaching events, and El Niño.
Originally expected to last just 2 - 3 years, QuikSCAT made it past ten, a testament to the skill of the engineers that designed the satellite.
Last week, though, NASA announced that a new QuikSCAT-like instrument called ISS-RapidScat will be launched in 2014 on a SpaceX Dragon cargo spacecraft, and installed on the International Space Station (ISS.) In a clever reuse of hardware originally built to test parts of NASA's QuikScat satellite, the cost of the new instrument will be much lower than any previous scatterometer launched into orbit.
Three valuable alternatives to QuikSCAT are available, but none are as good as QuikSCAT was. There's the European ASCAT satellite, launched in 2007. Like QuikSCAT, ASCAT can measure global wind speed and direction twice per day. However, ASCAT covers only 60% of the area covered by QuikSCAT, which saw a swath of ocean 1800 km wide. ASCAT sees two parallel swaths 550 km wide, separated by a 720 km gap. I find it frustrating to use ASCAT to monitor tropical storms, since the passes miss the center of circulation of a storm of interest more than half the time. On the plus side, ASCAT has the advantage that the data is not adversely affected by rain, unlike QuikSCAT. The other main alternative is the OSCAT instrument, which was sent into orbit on September 23, 2009, on the ISRO (Indian Space Research Organization) Oceansat-2 satellite. Like QuikSCAT, the OSCAT has a swath 1800 km wide that covers 90% of Earth's area every 24 hours. The winds at the edge of the swath are not as accurate as the ones in the middle. Moderate and heavy rain cause bogus winds that can be up to 45 mph too high. The resolution is not as high--25 km, versus the 12.5 km resolution of QuikSCAT and ASCAT. The third option is the Windsat instrument aboard the Coriolis satellite (launched in 2003), which measures wind speed and wind direction using a different technique. Evaluation of these data at NHC and NOAA's Ocean Prediction Center (OPC) shown the winds to be unreliable in and around tropical storms.
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2342
It carried a scatterometer--a radar instrument that can measure near-surface wind speed and direction over the ocean. Forecasters world-wide came to rely on QuikSCAT wind data to issue timely warnings and make accurate forecasts of tropical and extratropical storms, wave heights, sea ice, aviation weather, iceberg movement, coral bleaching events, and El Niño.
Originally expected to last just 2 - 3 years, QuikSCAT made it past ten, a testament to the skill of the engineers that designed the satellite.
Last week, though, NASA announced that a new QuikSCAT-like instrument called ISS-RapidScat will be launched in 2014 on a SpaceX Dragon cargo spacecraft, and installed on the International Space Station (ISS.) In a clever reuse of hardware originally built to test parts of NASA's QuikScat satellite, the cost of the new instrument will be much lower than any previous scatterometer launched into orbit.
Three valuable alternatives to QuikSCAT are available, but none are as good as QuikSCAT was. There's the European ASCAT satellite, launched in 2007. Like QuikSCAT, ASCAT can measure global wind speed and direction twice per day. However, ASCAT covers only 60% of the area covered by QuikSCAT, which saw a swath of ocean 1800 km wide. ASCAT sees two parallel swaths 550 km wide, separated by a 720 km gap. I find it frustrating to use ASCAT to monitor tropical storms, since the passes miss the center of circulation of a storm of interest more than half the time. On the plus side, ASCAT has the advantage that the data is not adversely affected by rain, unlike QuikSCAT. The other main alternative is the OSCAT instrument, which was sent into orbit on September 23, 2009, on the ISRO (Indian Space Research Organization) Oceansat-2 satellite. Like QuikSCAT, the OSCAT has a swath 1800 km wide that covers 90% of Earth's area every 24 hours. The winds at the edge of the swath are not as accurate as the ones in the middle. Moderate and heavy rain cause bogus winds that can be up to 45 mph too high. The resolution is not as high--25 km, versus the 12.5 km resolution of QuikSCAT and ASCAT. The third option is the Windsat instrument aboard the Coriolis satellite (launched in 2003), which measures wind speed and wind direction using a different technique. Evaluation of these data at NHC and NOAA's Ocean Prediction Center (OPC) shown the winds to be unreliable in and around tropical storms.
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2342
