5:15 PM - 6:30 PM
[PEM16-P13] Ionospheric Hole made by the Kwangmyongsong-4 Rocket Launched from Norh Korea on Feb. 7, 2016, and Increase of Thrust of its Second Stage Engine
Keywords:GNSS-TEC, North Korean rocket, ionospheric hole
On February 7th, 2016, a new rocket Kwangmyongsong-4, was launched southward from the same launch pad at 9:31 JST (0:31 UT), and succeeded in putting an earth-observing satellite (KMS-4) into orbit. Here we studied the ionospheric hole made by this launch. Unlike the previous case, we could detect clear hole signatures with multiple satellites of both GPS and GLONASS. The hole emerged at 6-7 minutes after the launch, and its position and emergence time were similar to the previous 2012 case. However, the areal extent and the amount of TEC decrease were much more in the 2016 case. In the attached figure, we compare the TEC time series observed with GPS Satellite 29 from GEONET stations in western Kyushu, together with the past three cases. Clearly, the TEC decreases in the 2016 case are much larger than the past cases.
In all the rocket (missile) launches from North Korea, the first stage engine did not reach the ionospheric height, and it was the second stage engine that made the ionospheric holes (Ozeki & Heki, 2010). The overall figure of the present Kwangmyongsong-4 rocket looks quite similar to the previous Unha-3, but its payload (satellite) is suggested to be larger in size than the 2012 case. The thrust of the second stage engine may have been made more powerful to put this relatively large satellite into orbit. However, the vertical TEC above the Yellow Sea in the present case was ~30 TECU, which is twice as large as in the 2012 launch, and the comparison of the thrust in the two cases may need a more quantitative discussion.
Furuya, T. and K. Heki, Ionospheric hole behind an ascending rocket observed with a dense GPS array, Earth Planets Space, 60, 235-239, 2008.
Nakashima, Y. and K. Heki, Ionospheric hole made by the 2012 North Korean rocket observed with a dense GNSS array in Japan, Radio Sci., 49, doi:10.1002/2014RS005413, 2014.
Ozeki, M. and K. Heki, Ionospheric holes made by ballistic missiles from North Korea detected with a Japanese dense GPS array, J. Geophys. Res., 115, A09314, doi:10.1029/2010JA015531, 2010.
Figure caption: TEC time series in the 2016 February launch of Kwangmyongsong-4 from North Korea are compared with the past three cases, i.e. the 1998 Taepodong-1, the 2009 Taepodong-2, and the 2012 Unha-3 launches. The 2016 case shows much larger TEC decreases than these past launches.