24 dicembre 2008

La meteorologia viaggia sui canali data del satradio

Questa interessante storia della NASA parla di alcune avanzate applicazioni meterologiche che sono state trasformate, grazie alla collaborazione con alcune società commerciali, in altrettanti servizi di previsione del tempo a brevissimo termine distribuiti attraverso i canali dati dei satelliti di radio digitale ex-XM Radio. Secondo l'articolo ci sarebbero già diverse decine di migliaia di abbonati tra i numerosi proprietari di barche da diporto e pesca che solcano le non facili acque intorno ala Florida, un'area dove i mutamenti atmosferici possono essere tanto repentini quanto devastanti. XM Radio ha una sua divisione specializzata in servizi meteo raggiungibile sul sito XMWXweather. Tra i fornitori dei servizi avanzati di cui parla la NASA - i dati sono basati sui dati forniti dallo Short-term Prediction Research and Transition Center (SPoRT) - ci sono società come WorldWinds Inc e WxWork. I dati SPoRT sono disponibili gratuitamente anche via Web, all'indirizzo già riportato. In questo caso i canali XM trasporano gli overlay di informazioni sul tempo elaborate e aggiornate in tempo reale. I dati viaggiano via satellite e finiscono sui navigatori di bordo dei natanti, dove vengono combinati con mappe digitali e posizionamento GPS. WxWorks per la ricezione e la decodifica delle informazioni ha anche realizzato, con la collaborazione di un produttore di antenne di bordo chiamato Digital Antenna, un apposito ricevitore XM Radio. I servizi vengono proposti anche per la navigazione aerea e land based.
Eccco una applicazione interessante per una piattafoma satellitare come Sirius XM . Peccato che questa nicchia di prodotto non abbia ancora, evidentemente, un grande impatto sul mercato.

NASA's Gift to Mr. Claus

Terry Claus, captain of a 53-foot charter boat called The Qualifier, received something that helped him avoid a disaster at sea--namely, data transmitted onto his GPS screen. If "data" isn't your idea of a Christmas gift, just listen:

"One night, my wife, children, and I were fishing for swordfish 25 miles off the Miami coast," says Claus. "We saw black clouds to the west. That's not unusual where we live. Florida storms sometimes build over land and then dissipate. But that night, when I checked the radar on my GPS, I saw an incredible line of severe thunderstorms moving towards us -- and fast."

"I checked the lightning strike screen, and it looked like a chained link fence of continuous lightning," he continues. "I shouted, 'Reel in the lines! We have to get out of here fast!' I could see on the screen where the cloud mass was weakest, so I followed that route. A 747 jet flew overhead and seemed to be following the same route we were following. We must have been looking at the same data! We made it to port safely."
NASA's SPoRT program (short for Short-term Prediction Research and Transition) at the Marshall Space Flight Center, helped make Claus's bird's eye view of the weather possible that night.
The SPoRT team assists a small company called WorldWinds, Inc. in Slidell, Louisiana in making some premiere products available to the marine community. NASA supplies WorldWinds with high resolution satellite data on ocean and atmospheric conditions. WorldWinds repackages the data, along with other weather/data products they generate themselves and some radar data from WxWorx, for the mariners along the Gulf and Atlantic coasts. About ten thousand of them subscribe to the data service via XM satellite radio.
Any time they feel a little edgy about what the day, or night, might hold in store, Claus and other boaters can scrutinize a GPS for answers. With the push of a button, a boat captain can choose from among views of sea surface temperatures, Doppler radar, wind speed, wind direction, lightning strikes, and more, both real-time and forecasted.
"Our job is to help businesses and other government agencies find vital ways to use our data," says Dr. Gary Jedlovec, satellite meteorologist and SPoRT principal investigator. "In fact, weather forecasters all over the US, including coastal regions of Florida, use many of our data products to improve forecasts. Accurate marine weather forecasts are especially crucial to boaters. They sure don't want to be surprised by high winds, 10-foot waves, and lightning strikes."
Sea surface temperatures can be a significant factor in spawning the storms Claus dreads. Sea surface temperatures also play an important role in creating just the right setting for something Claus loves – a lot of fish in one place. Each species of game fish has a range of water temperature they prefer, so "SST charts" can lead a fisherman to his prize catch.
There's another thing that helps create the perfect ambience for a fish party – plankton. The green stuff is almost always the most popular hors d'oeuvre. If an ocean area has a lot of plankton, it's a likely gathering spot. The SPoRT team knows how to use NASA satellite data to find such areas. High chlorophyll concentration, indicated in satellite data by greenness (the greener the more chlorophyll), means lots of plankton.
"If you know where blue water [no plankton] meets green [more plankton], you'll find more bait fish, and then more catchable fish," says Claus. "Fish swim up and down the edge of the weed boundaries and also the defined edge where warmer water meets cooler water."
That's why WorldWinds uses the SPoRT sea surface temperature data along with SPoRT chlorophyll data as components in a fishing product called FishBytes that reveals when and where the impromptu fish parties take place. Like the weather data, this product is available via XM radio on a GPS.
NASA helps fishers find fish feasting. (Say that 10 times rapidly!) And what about the poor fish? It just doesn't seem fair.
"Most of our customers are charter fishing captains," says Benjamin Jelly of WorldWinds. "Environmental and conservation groups concerned for fish view us, and the charter fishers, in a positive light."
"When we take out charter clients, we follow the environmental laws concerning limit numbers and size," explains Claus. "And when we fish in tournaments, we use circular hooks for bait. It's a tournament rule. The fish can't swallow the hook, so the fish aren't hurt. Once we catch a fish, we release it immediately. In fact, an angler's tournament score is based on the number of releases he or she makes."
Many sport fishermen also participate in voluntary tagging programs. This allows researchers, including fisheries biologists and marine scientists, to garner more information about species numbers, migration patterns, and environmental preferences.
"There are many, many tournament participants, and literally thousands of recreational fishermen, some of which fish year-round," says Jelly. "So our system allows more fishermen to apply more tags and collect more data about these species. That's good for the fish."

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