Hundreds of volunteers fanned out across New Jersey yesterday, looking in train stations and wooded areas to find and count the state's homeless.

The statewide effort, New Jersey's most ambitious and best-organized ever, was launched to fulfill a federal requirement to conduct a census of the homeless every two years. The numbers are used to determine federal grants for homeless services.

In 2005, the census counted about 11,000 homeless, a number well below the 25,000 or so who social-services providers believe live in the state.

Part of the reason for the discrepancy is that the federal Housing and Urban Development Department has a relatively narrow definition of homelessness.

The first question on the survey administered for yesterday's census was: "Where did you sleep last night?"

For anyone who answered "at a friend's house," the survey ended there. By the federal rules, those people are not homeless, even if they do not have a permanent residence.

Another reason for a count that comes up below expectations is that the homeless can be hard to find.

Bill McLaughlin, a Legal Services lawyer, and Tim Bash, an engineer who is trying to start a homeless mission, walked through downtown Camden yesterday afternoon looking.

McLaughlin spotted a tent in a wooded area behind the city's police headquarters, but no one seemed to be inside.

He and Bash strolled through the waiting area at the CAMcare health clinic nearby, wondering how they would tell if any of the people there were homeless.

It turned out not to be hard: One man waiting for an appointment was wearing several layers of clothing and had a pushcart parked next to his seat. The man, who said he had mental-health problems, was indeed homeless, living in an abandoned house. After he answered all of McLaughlin's questions, he said he was glad to help - and to be counted twice. He had already been given the survey a few hours earlier.

For others, the experience was harrowing.

Social worker William Outlaw's group walked through a dicey area of this impoverished city in the early morning, finding 56 homeless over five hours.

About a dozen of them poured out of an abandoned home being used as a crack house, he said, grateful for the offer of free flu shots.

Outlaw's group also found people sleeping in the Walter Rand Transportation Center and in cars in a junkyard.

In Camden, as in 42 other spots across the state, the homeless came to the census-takers who were set up at facilities providing an array of services as part of Project Homeless Connect.

Cathedral Kitchen was offering lunch, socks, coats and other clothes, flu shots, blood-pressure tests and information from groups that provide services to the homeless.

The people gathered there - mostly men - ranged from the newly homeless, such as Cleyman Ramirez, who has been on the streets a few months, to Calvin Fisher, who said he has been homeless for nearly 30 years.

Ramirez, 23, was hopeful when he saw snow flurries out the window. The landscaper, who came to the United States from Guatemala about five years ago, said he and his five roommates could no longer afford the $1,200 rent they paid to stay in a Gloucester City house because work dried up this fall. A few snowplowing jobs might be enough to get a roof over his head again, he said.

Fisher, 49, said he has suffered from schizophrenia since he was discharged from the Marines in 1977. Fisher said he's been living under the Ben Franklin Bridge.

The government would only give him housing help if he let someone else manage his money, he said. But he won't agree to that.

"I try to survive, try hard to survive. I'm surviving," he said.

The results of the statewide homeless census are expected to be compiled around the end of February, said Alison Recca-Ryan, New Jersey director for the Corporation for Supportive Housing, which is coordinating the New Jersey count.

"It's just a shame how many homeless people there is in this country," said one of the homeless, Steve Rogers, 43. He is a former chef who says he doesn't qualify for housing assistance because of a bad credit history and a robbery conviction 13 years ago. "It doesn't make any sense," he said.