Pity the golfer, braving cold and wind and sun, the threat of rain or darkness, sluggish partners, and, on occasion, unreliable golf carts.

Enter the Golfomat, a slide projector that displays on a special screen a picture of a hole just as a golfer would see it if he were about to tee off at a golf course. The user stands about 20 feet from the screen, on artificial grass, and drives a real ball with a real club at the simulated hole.

The Fairfax County Park Authority hopes to have four Golfomats installed at the Pinecrest Park golf course in Annandale by early next year.

"It's kind of a cross between a bowling alley and a video game," said the park authority's golf course section supervisor, Paul Engman. "It will provide a challenge for almost any golfer."

After the golfer hits the ball, a computer measures the speed, trajectory and spin of the ball as it hits the screen and calculates where it would have landed if the course were real. It fast-forwards the projection to that point so the golfer can swing again. When the golfer reaches the green, he steps over to a small putting green to get the ball into the hole. Play runs for 18 holes.

Players can choose from a simulation library of seven famous golf courses, including Pebble Beach in California, Butler National in Illinois and Congressional Country Club in Bethesda.

"Really, it kind of simulates playing golf at some of the better courses in the world," Engman said.

Golfers can use the machine at night and in bad weather, he noted, and golfers need not spend time walking from hole to hole. Players can reserve blocks of time in advance, he said, allowing them to avoid waiting to play.

Plans call for installing a refreshment stand in the building, so golfers never need be more than yards away from a snack.

"It will be a smashing success," predicted Arthur Angelos, president of Golfomat Inc., the simulators' Alexandria-based manufacturer.

In fact, the Golfomat seems to provide just about everything but exercise.

"The only thing I could imagine an indoor {golf simulator} would do for you is give you muscles in your arm," said Christine Lamdegger, administrator of the Cardiovascular Center of Northern Virginia in Falls Church.

Angelos said there are few Golfomats in the United States -- the nearest is in Duluth, Minn. -- but he sells about 200 a year, mainly in overseas markets.

Golfomats are especially popular in Japan, where country club entrance fees typically run $100,000 and annual dues $50,000 because land is scarce, according to Angelos.

Two-thirds of Japanese golfers never play on golf courses, instead using driving ranges, rooftop putting greens, back yards or simulators, he said.

Golfomat is not quite like real golf, he acknowledged. There is no wind, rough grass or trees, he said, and the artificial turf is always dry.

Special house rules govern sand traps and lakes, he said; a player landing in one may be penalized a stroke, or required to use a smaller club. Scores are usually about 5 percent higher with Golfomat than they would be in the open, he said, but he added that about four-fifths of the strokes are realistic.

Also, the screen displays the distance a golfer has shot the ball after each drive, an improvement over driving ranges, Angelos said. His firm charges $18,000 per machine for orders of two or more, he said.

The authority plans to spend about $225,000 for four machines and the renovation of a building to house them, according to Engman. The money will come from a trust fund the state established when it built the Pinecrest course, and from money left over from the course's construction. He estimated that the machines will pay for themselves in about five years.

The fee for using them will probably be similar to greens fees, or about $6 to $12 per person for three or four hours' use, enough to play 18 holes. He said the authority might start Golfomat leagues or use the equipment for lessons. The authority regularly provides grants for use of its facilities in case of financial need, he said.

Engman said that one way to market the machines might be to put up a movie theater-style marquee at the building. "You could have something saying, 'Now Playing: Pebble Beach,' " he said.