These were "low flying" missiles (in the tests last week by NK), they couldn't track them readily.
Report: Radar in South Korea network could not track missiles
By Elizabeth Shim
May 13 (UPI) -- North Korean missiles tested last week may have been only partly detected in South Korea despite an extensive network of early warning radar in the country, according to a local press report.
EDaily reported Monday the Peace Eye airborne early warning and control aircraft, and early warning systems on Aegis ships, may have not detected the missiles after launch. The South Korean military said the reason why the missiles were not tracked on Aegis destroyers is "currently under analysis," according to the report.
The missiles were tracked largely through the South Korean air force's early warning radar, most likely Green Pine missile-defense radar.
Read more at: https://www.upi.com/Top_News/World-News/2019/05/13/Report-Radar-in-South-Korea-network-could-not-track-missiles/3231557759758/?spt=su&or=btn_tw
So, we'll see if this throws us a curve.
