Seoul offers plan to verify radar data to Tokyo

South Korea proposed a mutual expert verification of military radar data to Japan to address a highly charged dispute over its use of a ship-based radar last month, a military official in Seoul said Wednesday.

Seoul made the proposal during general-grade talks with Tokyo in Singapore Monday. There, the two sides failed to narrow differences, as Japan refused to give any specific answer to the request for “objective and fair” verification.

The spat erupted following Tokyo’s claim that South Korea’s 3,200-ton Gwanggaeto the Great-class destroyer locked its fire-control tracking radar - called STIR-180 - on Japan’s Maritime Self-Defense Force’s P-1 patrol aircraft on Dec. 20.

Seoul has rejected the charge, saying the warship was then on a mission to rescue a North Korean vessel drifting in the overlapping exclusive economic zones of South Korea and Japan, and that it only used its search radar, not its tracking radar.

“[At the talks], we asked Japan to offer specific radar frequency data that it claims to have collected when the incident occurred, such as the time, location and angle regarding the operation of the tracking radar,” the official told reporters on condition of anonymity.

“On the premise that Japan will offer that data, we called for consultations on the verification method,” he added.

Seoul has repeatedly demanded a “smoking gun” - radar data that Tokyo said it had detected - to vouch for the authenticity of its claim. But in a counterproposal, Tokyo called for Seoul’s disclosure of all frequency information on its destroyer’s STIR-180, which could threaten the safety of the warship and its sailors

“Frequency data is like the very life of a radar system [...] In an electronic warfare scenario, we can’t use the radar unless we replace it if all frequency information has already been disclosed,” the official said.

Seoul has already analyzed all data related to the destroyer’s use of radar equipment on the day of the incident and concluded that the warship did not send out any radar tracking signals toward the Japanese plane.

“We have clear-cut scientific evidence to corroborate our position that our STIR did not send out any signals,” he said.

On Tuesday, Choi Hyun-soo, the South Korean Defense Ministry’s spokeswoman, called Japan’s demand for the disclosure of all information on the destroyer’s tracking radar “hardly acceptable and rude.”

At the Singapore talks, Seoul officials also reiterated that the Japanese plane made a threateningly low-altitude flight toward the South Korean destroyer even when it was apparently aware of the humanitarian operations.

The Japanese aircraft flew just about 150 meters (492 feet) above the destroyer at some point during the radar incident.

Sources said that Seoul has criticized the Japanese plane’s flight pattern as being “in breach of international customs and ungentlemanly.”

The two sides are expected to hold another round of consultations over the issue, though they have yet to set a date.

Yonhap