A new bill introduced in the City Council on Wednesday would lift the “veil” of secrecy surrounding the NYPD’s high-tech, military-grade surveillance tactics, its authors say — but police say the bill would harm their efforts to prevent terrorist attacks.

The department purchases and deploys equipment like “x-ray vans” that use radiation to see through walls and vehicles, and cell phone locators known as “stingrays” to track individuals’ locations, capture data or disrupt service over a general range — all without disclosing any information relating to the technology to the public or city lawmakers, according to the bill’s authors, City Council members Daniel Garodnick and Vanessa Gibson.

“I believe that the NYPD should have a strong capability for surveillance. We live in uncertain times and surveillance is critical to their operations in keeping New Yorkers safe,” said Garodnick, who represents Manhattan’s East Side, at a news conference with advocates outside City Hall. “The key point is this: Civilians are in charge of the police force, not the reverse. We need to be able to understand why decisions are being made to ensure public trust in our criminal justice system.”

Gibson, a Bronx councilwoman and chair of the Council’s Committee on Public Safety, said the issue of surveillance is particularly sensitive for the large community of Muslim New Yorkers in her district.

She considered the bill a “lifting of the veil on surveillance technology — thereby ensuring that every New Yorkers’ rights are respected by the NYPD.”

The bill, known as the Public Oversight of Surveillance Technology, or POST Act, would require the NYPD to issue on its website an “impact and use” policy for each piece of surveillance technology in its arsenal.

The site would detail what the tools are and how they work; the internal policies on use of the equipment and an explanation of how the department shares and protects the sensitive information they collect.

Police Commissioner James O’Neill and Larry Byrne, the department’s deputy commissioner for legal affairs, voiced sharp opposition to the bill at an unrelated news conference on Wednesday.

“The way we do business, we try to be as transparent as possible,” said O’Neill. “This bill would not be helpful to anyone in New York City.”

Byrne added that it was a “very bad idea” and a “misguided attempt” that has no shot of becoming law. He went on to claim that if the Police Department published such information online, it would be featured in the “next issue of Inspire magazine,” al-Qaida’s newsletter for radicals seeking guidance in attack planning.

“It would be devoted to: Here are all of the technologies the NYPD uses to prevent terrorist attacks; here’s how you can disable these technologies; here’s how you can avoid these technologies,” he said.

Sensing the potential for police pushback, Garodnick said the bill was carefully constructed over the course of about a year to ensure that it was written in a way so that it doesn’t “impact the ability of our police use the technology” or jeopardize anti-terror operations. The lawmakers said similar legislation was appearing in other cities and agencies across the country.

With Alison Fox