Like pieces of a shattered mirror, the 143,000 asylum applications filed with the federal government reflect fragmented images of political discontent, violence and fear abroad. The difficulty for the government--especially the State Department--is judging whether these images accurately reflect reality.

The job has gotten tougher in the three years since U.S. immigration laws were broadened to conform to U.N. standards on the treatment of refugees. Since then, the number of applications for asylum in this country has increased more than 60-fold.

The final rulings in these cases are made by the Justice Department's Immigration and Naturalization Service, or, if a decision is appealed, by immigration judges or the federal courts. But the crucial "advisory opinions" in each case are made by a group of six State Department officers in the Office of Human Rights and Humanitarian Affairs.

They processed the claim of Hu Na, the 20-year-old tennis star from the People's Republic of China; they advise the INS what to do with the laborers, peasants and students who say they will be persecuted--even killed--if they return to Ethiopia, El Salvador, Haiti or Iran. In virtually every case, INS officials say, they follow State's advice.

Earlier this month, the government agreed to give Hu Na asylum, further disrupting its prickly relations with Peking. But Hu Na is the exception. In two-thirds of the 11,548 cases decided last year, the government decided the foreigners' fears were unfounded.

"The key to the concept of asylum is targeting," said Elliott Abrams, assistant secretary of state for human rights and humanitarian affairs. "It's not sufficient to note that the country an applicant comes from is repressive, violent or poor. You must show something about you as an individual that would make you a target of persecution--your religion, your race, something."

Abrams refused to talk about the details of the Hu Na case--all applications are supposed to remain confidential--but he strenuously rejected the idea that diplomatic or policy considerations play a role in the decision, or that requirements are lowered for a prominent figure.

"Although the facts of each case are different, standards of proof do not vary from case to case," he said.

But, he said, "A person's notoriety might well lend credence to the claim that he could be persecuted if he went home . . . . Famous people are more likely to come to the attention of their government, and that affects the decision."

Some immigration attorneys and congressional critics say the assertions of evenhandedness are belied by the statistics. They argue that individuals from countries with communist or Marxist-oriented governments have a better chance of gaining asylum than those from repressive governments friendly to the United States.

For instance, in fiscal 1982, 6 percent of the applications from Salvadorans, whose country has been wracked by three years of civil war, were accepted; the figure for Haitians was 7 percent. The acceptance rate for nearby Nicaragua, where the revolutionary Sandinistas are in power, was 26 percent. Last year, a U.N. investigation accused the United States of having a "systematic practice" of returning Salvadorans who had requested asylum, regardless of the merit of their claims.

Abrams rejects such arguments and says it is fairer to compare Nicaragua to other countries where governments have been overthrown, such as Ethiopia and Iran. About 44 percent of Ethiopians' applications were accepted last year, as were 61 percent of Iranians'.

Of more immediate concern to those pressing Salvadorans' cases is the government's failure to grant Salvadorans a temporary safe haven here through an administrative procedure known as "extended voluntary departure." Such provisions were granted for Lebanese and Nicaraguans during their countries' civil wars, and are now in effect for persons from Poland, Ethiopia, Uganda and Afghanistan.

Salvadorans "are entitled to extended voluntary departure and the administration is not recommending it, for political reasons," charged immigration attorney Michael Maggio. "They don't give a damn about the lives of the individuals involved."

Abrams, however, makes a distinction between foreigners who genuinely fear persecution and what he calls "economic migrants" to this country. "We have no moral obligation to economic migrants," he said.

Mixed in with the political arguments are more practical worries, such as documenting claims of persecution. "The State Department gets a cold file in which someone says, 'I heard the authorities were after me so I took a boat out,' " explained David Martin, who served as special assistant to Patt Derian, Abrams' predecessor. "That may be true. The big thing is to evaluate the credibility of the witness . . . . It isn't always reasonable to expect documentation." But when one examines the broader issue of asylum policy, he said, "If you don't apply legal standards narrowly and precisely, asylum policy can become quite formless and be perceived as running out of control."