WASHINGTON (States News Service) Forty years ago predicting the weather was about as accurate as guessing who would win the lottery.

Tropical storms and cyclones swept up unknowing ships at sea and tornadoes, like those that ripped through Texas earlier this week, could be measured only as they inflicted damage.

In the days before television anchors could warn on a Wednesday of a rainy time for the weekend, weather monitoring was limited to wind, temperature and rainfall gauges aboard airplanes, balloons and ships.

All that changed on April 1, 1960 when the government launched the first weather satellite -- TIROS 1 -- into Earth orbit from Cape Canaveral, Florida.

"Weve come a long, long way," said Dan Henry, a meteorologist with WJLA-TV in Washington. "The high-resolution satellite images now that we have access to, that were getting on a much more constant basis, really paint a vivid 3-D image of severe thunderstorms."

As weather satellites have gained from computer technology in the last ten years, the practical applications are only starting to be understood and harnessed, said Krishna Rao, chief scientist for Satellites and Information Services with the Commerce Departments National Oceanic and Atmospheric Administration (NOAA).

"In the early days, we were saying, Here is the data, use it," Rao said. "Now its more, Give me the data, give me the data."

Thanks to the internet, meteorologists can view high-resolution satellite images of incoming storms, allowing coastal areas enough advance warning to evacuate.

And the amount of images a satellite can send in an hour has increased from one image per hour a decade ago to about 40 today.

As a result, Rao said, "people are getting sort of addicted to the data."

Experts and scientists from NOAA, NASA and outside groups will gather April 5 in Washington to celebrate the 40^th anniversary of TIROS 1, the first weather satellite. Nine other identical satellites were put up in the next three months.

Each TIROS, which stands for Television Infrared Observation Satellite, was essentially a black-and-white television set with a camera attached, said Rao, who has worked at NOAA since 1961.

Orbiting Earth 450 miles (725 kilometers) overhead, the 10 TIROS satellites carried one-inch tubes that absorbed images and transmitted data to ground stations, all in a matter of minutes. On the ground, the data was photographed and processed into a print, like a roll of film.

For the first half-year, the satellites were limited to taking pictures in the daylight, because they lacked infrared capabilities.

Infrared sensors, the first of which measured areas 5 to 6 miles (8 to 10 kilometers) across in 256 shades of gray, offered a major breakthrough to weather research. Each shade represented a different degree of temperature -- from white indicating cold to black representing hot.

Knowing cloud temperature allowed scientists to understand their height. That, in turn, helped airplane pilots chart a clear path and allowed sea-faring oil tankers to know where to receive a boost from fast-moving Gulf Stream patterns in the Atlantic Ocean.

Now, finer-resolution infrared can measure temperatures in areas as small as a half-mile, and with small receiving stations attached to personal computers, fishermen can monitor sea surface temperatures to aid them in finding the perfect catch.

The second breakthrough after TIROS occurred in 1970, when NOAA sent up new satellites with improved sensors that could measure five different wavelengths of light, instead of three.

Modern weather satellites have six different channels, each one snapping a photo of a different wavelength. Meteorologists can pick and choose, depending on what they want to measure -- from volcanic dust, to aerosols swirling around the globe, and recently, depletion of the ozone layer.

NOAA runs two types of weather satellites for long- and short-term observations, which together give a complete picture of Earths weather system.

• Geostationary operational environmental satellites snap real-time photos of various regions of the United States to predict floods, hurricanes, thunderstorms and other severe weather patterns as quickly as possible with the help of Doppler radars and other ground systems.
• Polar-orbiting environmental satellite offer a larger, more long-term picture of the environment. Snapping visible and infrared photos that measure temperature and moisture, these satellites track patterns affecting the weather and climate of the United States.

Both sets of satellites also carry search and rescue transmission instruments so that pilots and mariners in distress can relay messages through them for help.

The first in the latest fleet of U.S. weather satellites was launched in 1998. Four more will be launched by 2008.

More and more people are set to gain from data gleaned from weather satellites as computer technology improves, Rao said. Now anyone with a ground-receiving station can pick up regional broadcast signals.

"The more computer power, the more data is going to be available," he said.

An example of a future use for high-resolution data, Rao said, is measuring climate change. The extent of global warming should become clearer 10 years from now when technology now in space allows scientists to measure detailed changes over a decade's time.

"I dont think anyone expected that these things would provide that kind of information," said Rao.