The Japanese Ministry of Defense (MoD) has released an 18 second audio file containing what Tokyo claims is the sound – converted from radio waves – recorded when a Republic of Korea Navy (RoKN) destroyer locked its fire-control radar onto a Japanese Maritime Self-Defense Force (JMSDF) Kawasaki P-1 maritime patrol aircraft (MPA) as it flew over the Sea of Japan (also known as East Sea) on 20 December 2018.
In what it referred to as its “final statement” on the incident, the MoD said on 21 January that the radio waves directed at the P-1 showed “characteristics unique to that of fire-control radars”, thus “confirming” that the MPA “was continuously irradiated for a certain period, multiple times by the fire-control radar (STIR 180)” fitted onto RoKN KDX-I-class destroyer Gwang Gae To Daewang (pennant number 971).
Fire-control Radar Detection Sound:
www.mod.go.jp/j/approach/defense/radar/img/fc.wavSearch Radar Detection Sound:
www.mod.go.jp/j/approach/defense/radar/img/search.mp3The Ministry of Defense (MOD) considers this a hazardous act that may cause unintended consequences, and it is extremely regrettable that such incident occurred.
After the MOD's public announcement on December 21st, the ROK Ministry of National Defense has released video footage etc. regarding this incident, but there are different claims from our position.
Fire-control radars are directed at its target immediately before firing, and to aim it at foreign aircrafts without a rational reason is an extremely hazardous act that may cause unintended consequences.
According to CUES (Code for Unplanned Encounters at Sea), a code adopted in 2014 by navies from 21 countries including Japan and the ROK, aiming fire control radars is considered a simulation of attack, and is stipulated as an action a commander might avoid.
In response to the occurrence of a serious incident of such nature, the MOD lodged a strong protest and requested the prevention of recurrence to the ROK. However, not only did the ROK deny the fact this incident occurred, their actions regarding the incident entirely focus on demanding Japan to "stop distorting facts" and "apologize for conducting a threateningly low-altitude flight".
Upon careful and meticulous analysis by the MOD's specialized unit of the frequency, intensity, waveform, etc. of the radar waves directed at the MSDF P-1, the MOD has confirmed that the P-1 was continuously irradiated for a certain period, multiple times by the fire-control radar (STIR-180) of the ROK destroyer that was being photographed. The STIR-180 was not mounted on the patrol and rescue vessel that was nearby at the time, and the fact the ROK destroyer directed its radar is clear from the footage released by the MOD on December 28, 2018.
The MOD has decided publicly disclose at the Ministry's website, upon processing for information security, the data of the radar waves converted to sound that the P-1 patrol aircraft crew heard inflight, as further evidence of the irradiation of the fire-control radar.
In general, fire-control radars continuously direct radar waves to its target in order to obtain the target's location, speed etc. to fire missiles and ammunition with precision. The data collected from the fire-control radar, such as wave forms, is clearly different from that of a surface search radar, which searches/detects targets in surrounding areas by emitting radar waves while rotating its head. Therefore, by analyzing the emitted radio waves, it is possible to determine its type and source of emission. The radio waves directed at the MSDF P-1 had shown characteristics unique to that of fire-control radars.
Although it is apparent from the result of MOD's analysis that this radar wave was emitted by the ROK destroyer being photographed by the MSDF P-1, for the objective and neutral determination of these facts, it is necessary that a comprehensive assessment is made upon comparison of Japan's data regarding the radar waves it has detected, and the ROK's data regarding the detailed capability of the fire-control radar equipped on the ROK destroyer, based on the principle of reciprocity.
In this light, at the working-level meeting held on January 14, 2019, the MOD proposed a joint verification of data based on the principle of reciprocity, by comparing the factual evidence of the incident such as the detected radar waves and its sound conversion, to the ROK radar's capabilities and record of use. However, this proposal was rejected. The MOD had made a proposal of the same intent during the working-level meeting held on December 27, 2018. In addition, the MOD also brought the data of the sound conversion of the detected radar waves, as evidence to contribute to the verification of facts, to the meeting on January 14 and proposed to have the ROK listen to it there, but this proposal was also rejected.