To soldiers and citizens on the ground, few experiences are more terrifying than being subjected to an intense and sustained aerial bombardment such as U.S. and allied military forces began this week over Iraq, according to military experts and historians.

The violent explosion of munitions dropped from planes far overhead can obliterate a building and all those inside in a few seconds. The bombs can also generate localized shock waves and air blasts worse than any earthquake or tornado, and blind or deafen those fortunate enough to survive, experts say.

The air war against Iraq and its military forces began with more than 1,000 bombing runs in the first 14 hours, 60 percent to 80 percent of which reached their targets and precisely discharged their munitions, according to initial estimates. At this rate, according to a senior military official, the coalition arrayed against Iraq potentially could drop 5,000 tons of explosives a day on Iraq.

The horrific firebombing of Dresden, Germany, in 1945 was caused by 4,200 tons of explosives and incendiaries. However, U.S. military officials say they are trying to avoid destroying major Iraqi cities, and killing tens of thousands of civilians, in the bombing campaign.

While most initial targets have been "strategic" Iraqi sites such as military headquarters, air defense networks, airfields, weapons depots, oil refineries and power plants, the next phase of what Joint Chiefs of Staff Chairman Gen. Colin L. Powell described as a campaign that will "grow and spread" involves repeated bombing of soldiers dug in at remote desert outposts.

"We're going to crater the place. We're going to make it look like a giant moonscape," said Robert Pape Jr., an aviation historian at the University of Michigan who has studied the impact of the air war in Vietnam.

During sustained air attack, soldiers and citizens of past wars recall feeling helpless and dazed, their ears bleeding, comrades stumbling or cowering from the combined effects of surprise, concussion and noise. Experts have said that the buffeting of shock waves and intense heat is sometimes like being struck in the chest with a heavy log; victims often suffer multiple bone fractures or collapsed lungs from an absence of oxygen in a blast or abnormal air pressure.

Battle-Hardened Affected

Under such firepower, even battle-hardened soldiers in World War II and Vietnam sometimes fled from bunkers or were found unable to fight.

"The morale of soldiers exposed to air attack crumbles very rapidly," said Richard Hallion, a professor of aerospace history at the National Air and Space Museum here. "A large shocking rumble is suddenly upon you, like the voice of God. The shock, fury, the noise. . . . The combination is deadly."

U.S. officials said more than a dozen types of ground-attack aircraft from five nations have been used in waves against Iraq the past two days. The bombers are protected by interceptors or electronic warfare planes and carry "payloads" of free-fall bombs or rockets guided to targets by sophisticated electronic sensors. In addition, more than 100 cruise missiles -- or winged, pilotless weapons -- have been launched from ships in nearby seas, amounting overall to the most intensive use of modern conventional weaponry in any conflict.

The largest of the planes were B-52 bombers, built in the 1950s and used extensively to pound the North Vietnamese in the late '60s and early '70s. Experts say three B-52s flying in formation are capable of saturating an area of nine city blocks with 328 bombs, enough to kill or injure everyone in the area.

"I don't think people appreciate how many people are going to die, how many Iraqis," said one U.S. military historian who has studied effects of aerial bombardment. "People are going to be blown apart. You won't be able to find these people. The battlefield will be littered with Iraqi body parts."

In one account of heavy B-52 bombing in North Vietnam, Navy Cmdr. James B. Stockdale, a prisoner of war in North Vietnam, recalled "when the ground shook, and the plaster fell from the ceiling . . . the guards cowered in the lee of the walls, cheeks so ashen you could detect it even in the light of the fiery sky."

Each of the 2,000-pound bombs routinely carried by a massive, 160-foot-long B-52 can produce a crater 36 feet deep and 50 feet in diameter. It can penetrate 11 feet of concrete and 15 inches of steel, while sending lethal shrapnel 1,200 feet.

The choice of bomb depends on the target. "Hard" targets such as dug-in bunkers and command and control centers may require large bombs with 1,000 to 2,000 pounds of explosives. Often, the bombs can be fuzed to detonate only after penetrating their targets. To frustrate repair and rescue, the bombs can also be set on delayed fuzes.

For "soft-skinned" targets, such as troops and fuel depots, incendiary and cluster bombs are employed. Instead of a single large explosion, the cluster devices release hundreds of small "bomblets."

Question of Accuracy

One of the largest question marks before the Persian Gulf war began was the accuracy and reliability of the Tomahawk cruise missile, which had never been used in combat and depends on distinctive geographic features to find and hit its target.

Officials said yesterday that roughly 80 percent of the Tomahawks fired from naval vessels into the desert during the first 24 hours appeared to have hit targets with high precision.

Early reports indicated that the F-117A "stealth" fighters used in the raid to hit heavily defended targets such as command headquarters, radio and TV towers and air defense systems also were effective. Similarly positive reports about two F-117As used in the 1989 U.S. invasion of Panama later proved exaggerated. The planes are coated with a novel, radar-absorbing material to hamper their detection.

Some of the munitions used in the bombing raids were so-called "smart weapons" assisted by on-board computers and guided to targets by radar and lasers, or television cameras mounted in their tips or bristling with detectors that seek out heat sources, such as idling tanks or electrical generators.

Two air-to-surface weapons presumed to have been used early in the conflict are the Shrike anti-radar missile and its more developed cousin, the HARM, or High-speed Anti-Radiation Missile. Both can be fired from the F/A-18 and A-6 Intruder and other aircraft in the gulf. The Shrike and HARM missiles do their work by homing in on the electronic signals generated by radar.

An important part of the raids so far has also been an invisible battle of electronic airwaves. Navy EA-6B Prowler, Air Force F-4G Wild Weasel and EF-111 Raven emitted invisible beams of energy, tuned to the frequency of a target signal, to deceive, distract and disarm Iraqi surveillance and command equipment.

Staff writer Evelyn Richards contributed to this report.

Tomahawk Sea-Launched Cruise Missile Length: 20 feet Weight: 3,200 pounds Speed: Up to 550 mph Warhead: Single warhead, conventional high explosive or nuclear Range: 700 miles for conventional land attack Contractors: General Dynamics Corp. and McDonnell Douglas Corp. Tomahawks were the first weapons used in pre-dawn raids on Iraq and Kuwait. Without placing a pilot's life in danger, the missiles knocked out heavily defended sites with great precision. HOW THEY WORK 1. A solid rocket booster launches the Tomahawk from its container, then is jettisoned when small jet engine takes over. 2. An inertial guidance system directs the missile to a pre-designated swath of coastline. Once over land, the missile flies roughly 100 feet above the ground, periodically measuring its altitude with a radar altimeter. The measurements are compared with descriptions of terrain stored in the missile's computer. 3. The Tomahawk repeatedly corrects course to more closely align with the pre-programmed flight path. When it nears the target, it takes a snapshot of the ground for comparison with photos stored digitally in its computer. The computer stores the equivalent of about 15 double-spaced pages of text. F-117A Type: Attack/fighter Speed: High subsonic Background: Designed to penetrate heavily defended sites, such as Iraqi communications centers, the F-117's "stealth" characteristics make it hard to detect until after it has released its weapons. Used against Iraqi air defense systems, operations centers, communications, radio and television towers F-15E Type: Dual-role attack/air superiority fighter Maximum speed: 1,650 mph Background: This sophisticated combat aircraft is extremely maneuverable and able to climb faster and turn more sharply than many other aircraft. The F-15E Strike Eagle can carry bombs for precision strikes in populated areas, reducing "collateral damage" to a minimum. Used against Iraqi missile sites, Scud missiles and air defenses F-16 Type: Fighter Maximum speed: More than 1,120 mph Background: The fast and maneuverable Fighting Falcon can sweep in low and fast, then drop its bombs on key targets, such as nuclear facilities. Used against Iraqi power plants, refineries and strategic missile sites Tornado Type: British fighter-bomber Maximum speed: 1,454 mph Background: The Tornado can carry a mix of bombs and missiles and is suitable for hitting such targets as airfields and command centers once other planes have suppressed defensive radar. F-111 Type: Long-range bomber Maximum speed: 1,650 mph Background: The F-111's long reach means it can be stationed far from the front, while still delivering a substantial load of bombs on a target. The plane is packed with high-tech gear for night bombing, making it ideal for pre-dawn raids like the ones on Iraq and Kuwait. Used against Iraqi airfields, air defenses, command and control sites. F-4G Wild Weasel Type: Twin-seat fighter Maximum speed: 570 mph Background: Aircraft is packed with electronic equipment to detect enemy radar systems, then destroy or suppress them. This blinding of the enemy's defenses enables bombers to follow the Weasels into the target virtually unopposed. B-52 Type: Long-range bomber Maximum speed: 595 mph Background: Used throughout the Vietnam War, the B-52 can fly at high altitudes, carpet-bombing targets or launching cruise missiles from great distances. B-52 strikes could devastate Iraq's troop concentrations and blast their fortifications. Used against Iraqi airfields and other hardened sites, possibly including bunkers and headquarters. A-10 Thunderbolt II Type: Attack aircraft Maximum speed: 449 mph Background: The slow and low-flying Thunderbolt is the Air Force's primary tank-killing aircraft -- virtually a slow-flying 30mm gun. The plane flies over enemy armored columns and tries to knock out tanks and personnel carriers. F/A-18 Type: Navy fighter-bomber Maximum speed: 1,118 mph Background: Navy and Marines' most modern fighter-bomber combination. The Hornet can jettison its bombs in seconds and become an agile dogfighter. Precise bombing gear on this high-tech fighter makes it ideal for leading night raids. AV-8B Harrier Type: Marine attack aircraft Maximum speed: 668 mph Armament: 25-mm cannon, Sidewinder and Maverick missiles. Background: Developed by the British and used in Falklands War, this plane can take off almost vertically from a short field or ship deck to support troops on the ground.