Gov't apologizes for mistakenly reporting launch of N Korean rocket

The Japanese government provided erroneous information that North Korea had launched a rocket Saturday, mostly because the Air Self-Defense Force was confused about radar information, a Defense Ministry official said.

‘‘We caused a great deal of trouble to the Japanese people. This was a mistake in the transmission of information by the Defense Ministry and the Self-Defense Forces,’’ Defense Minister Yasukazu Hamada told reporters. ‘‘I want to apologize to the people from my heart.’’

The government released information that ‘‘North Korea appears to have launched a projectile’’ at 12:16 p.m. via its email-based Em-Net emergency information system, but retracted it five minutes later, saying it was a ‘‘detection failure.’’

By then, media organizations at home and abroad had reported the rocket launch as breaking news based on the false information.

The confusion occurred after the North’s official Korean Central News Agency reported earlier in the day that the rocket ‘‘will be launched soon.’’ North Korea has said the launch is for a communications satellite but Japan, South Korea and the United States suspect the launch is a cover for a long-range ballistic missile test.

According to the Defense Ministry, the ground-based FPS-5 radar at the ministry’s Iioka research and development site in Asahi, Chiba Prefecture, picked up a trace over the Sea of Japan on the radar screen.

The information was immediately conveyed to the ASDF’s Air Defense Command in the suburbs of Tokyo, but the person who received it mistook the information for satellite early warning information provided by the U.S. military.

The satellite early warning information is based on data sent by the U.S. Air Force’s Defense Support Program satellite orbiting the Earth. Equipped with an infrared telescope, it is normally the quickest means to detect ballistic missile launches.

The erroneous information then got passed onto the SDF’s Central Command Post at the Defense Ministry headquarters, from which it was conveyed to the crisis management center at the prime minister’s office, according to the ministry.

The prime minister’s office sent an emergency e-mail message to local governments across the country and media organizations based on the false information.

One minute after the Central Command Post received the launch information, it was notified that the trace had disappeared from the radar screen and that no satellite early warning information had actually been received, the ministry said.

‘‘They should have confirmed on computer terminals that satellite early warning information had been received. The mistake could have been avoided if they had done so,’’ a ministry official said.

The official said he does not know why the airman at the Air Defense Command mixed up the radar and satellite early warning information.

A misstep was also reported at the local level in Japan’s northern areas, over which part of the rocket is set to pass if it flies according to the plan announced by North Korea.

Before the central government’s false report, the Akita prefectural government issued an erroneous report to all municipal governments in the prefecture that North Korea had ‘‘fired a missile,’’ and one of the municipal offices communicated the report to all households through a radio transmission for disaster management.

According to prefectural officials, a SDF member at the prefectural government’s disaster preparedness headquarters received a communication from the Defense Ministry that the rocket was ‘‘launched at 10:48 a.m.’’

The SDF member verbally communicated the message to a prefectural government official, who then passed on the information to relevant officials of all the municipalities through mobile phone text messages six minutes later, the officials said.

Sixteen of the 25 municipalities in the prefecture conveyed the central government-issued information to their residents via a community wireless system and other means, and corrected the information later.

Tottori Prefecture, also on the Sea of Japan, issued faxes to its municipalities soon after the central government issued the wrong information and had to hastily correct the content.