Armed with a tough new security law and determined to restore a bit of tarnished national pride, the Japanese government is preparing to try once again to open Tokyo's new international airport.

The last time it tried, seven weeks ago, a group of radicals slipped past police guards and smashed a roomful of air-guidance equipment in the control tower, forcing postponement of business at Narita airport, which has been a center of controversy for 12 years.

Since March, the government has strengthened security, rebuilt the control tower, and mobilized an emergency police force of some 13,000 men to control the radicals and farmers who oppose the airport.

With the opponents still vowing to block the airport's opening, there is an atmosphere of tension as both sides prepare for another violent confrontation. A technological escalation is under way in both camps. Police are ready to douse protesters with colored dyes to mark them for quick arrest and the radicals reportedly are gearing up to assault the airport with radio-controlled model airplanes.

Saturday is the new scheduled opening date. Japnese officials said they must succeed this time because national prestige is at stake.

The government announced yesterday that it will soon begin taking control of 34 small houses and two fortress-like structures near the airport that are used as headquarters and living quarters for the protesters.

The government has pushed through the parliament a special emergency law permitting seizure of the rustic, handmade buildings, called "unity huts," which are on private property. It applies to any structure within two miles of the airport. The law has been denounced by some as unconstitutional and its passage last week was opposed by the Comunist and Socialist parties.

Security forces have added a second 10-foot fence topped with spikes around the airport, giving it the appearance of a prison.Several ditches have been dug at the perimeter.

They have also sunk heavy steel plates underground to prevent radicals from tunnelling into airport property. It was through a sewer tunnel that the opponents made their way inside the grounds on March 26 when they distroyed the control tower. March 26 when they distroyed the control tower. Authorities are also fencing off a railroad line that Authorities also fencing off a railroad line that will be used to transport jet fuel from a nearby port.

The radicals, allied with the farmers who oppose the airport, have been preparing guerrilla attacks either to forestall the opening or to sabotage the airport if it is opened.

Last week, according to police reports, the opponents burned a new railway car destined for use on a commuter train that will carry passengers 40 miles from downtown Tokyo to the airport in suburban Narita.

Other incidents have included an attack on a police firing range at Osaka and arson in an office of Japan Air Lines and at a house owned by a farmer who has refused to oppose the airport.

Police have reported what they call alarming thefts of glass bottles that could be used for making thefts of glass bottles that could be used for making molotov coctails. They also assert that the radicals are using new rubber-stoppered bottles to make improved firebombs that will not explode unexpectedly and burn the person tossing the bomb, as several did in the March 26 attack.

Yesterday, police also expressed concern that the radicals may employ small radio-controlled model airplanes, normally sold as children's toys, to strike at airport facilities.

According to Japanese newspapers, the Transport Ministry is prepared to thwart such flying assaults by jamming the radio frequencies used to direct the model planes. It was feared, however, that the jamming signals might interfere with police communications around the airport.

The opposition is led bY Issaku Tomura, 69, who comes from a family that has sold farm implements in the Narita area for three generations. An uncompromising, articulate leader, he has in the past 12 years put together a solid alliance of embittered farmers, whose land was taken for the airport their symbol of irresponsible government and class exploitation.

Tomura, who also is a painter and sculptor, has the background of a true outsider. His family has been Christian for generations and he and his parents actively opposed military training in Japan's schools before World War II.

A decade ofopposition hae brought him an international reputation as a revolutionary who is willing to use force and to risk violence. He speaks of transforming the airport movement into a national revolutionary force of farmers, laborers and students.

Last week, the government made its first effort in 12 years to solve the impasse by dealing directly with the oppenents and suggesting that a compromise might be arranged. The effort failed when Tomura insisted that arrested prisoners be released and that the airport's opening be delayed indefinitely.

The airport has become an extreme embarrassement to the government of Prime Minister Takeo Fukuda, who has now staked his national prestige on opening it. His government is criticized by some who believe it has been too soft in dealing with the opponents and by others who think it has been unbending and authoritarian in refusing to try to negotiate a settlement earlier.