利用中壢特高頻雷達站52MHz天線於2009年7月19日夜間觀測得一筆位於150公里處的不規則體回波。經過各種分析方式表達其位於150公里處不規則體相對於雷達站的都普勒速度、頻譜寬、追蹤速度及雷達干涉法定位出來的三維結構與典型的散塊E層及與2008年2月5日所觀測得的一筆F層的回波訊號比較下，發現於150公里附近的不規則體其頻譜特性、追蹤速度與三維結構具有獨特性。因此150公里不規則體其回波特性及物理機制應獨立討論。 利用崙坪電離層觀測站所觀測得的電離圖與中壢特高頻雷達站的回波訊號，比較其兩者高度之間具有一定的相關性，證明在150公里處的回波為確實存在的；厚度與頻譜寬的比較有一定的相關程度，代表當電離圖觀測的厚度越厚則其內部的電漿運動越複雜，所以收到的回波訊號頻譜寬越寬；而電離圖所觀測得的臨界頻率與電子密度成正比，所以與特高頻雷達所觀測得的回波強度應有一定的相關性。The Chung-Li VHF radar had observed echoes of 150 km irregularities during nighttime of 2009/07/19 .After analyzing Doppler velocity、spectrum width、trace velocity and three dimensional echo location by radar interferometry which in 150 km height, and comparing to sporadic E and F region observed during 2008/02/05 could know that the spectrum characteristics、trace velocity and echo location of 150 km irregularities has uniqueness. The mechanism of 150 km should be discussed independently. Comparing the Ionogram which observed by Lun-Ping ionosonde station with echoes which observed by Chung-Li VHF radar, the correlation coefficient is highly trustworthy. It means the irregularities existed definitely in 150 km. The thickness of Ionogram is dependent to the spectrum width observed by VHF radar. The critical frequency observed by Ionogram is also proportional to electron density may have dependence between the echo power observed by VHF radar .
