AKITA--The Defense Ministry admitted that its reliance on the Google Earth app instead of onsite inspections led to errors in its study report on candidate sites for the Aegis Ashore missile defense system.

Senior ministry officials admitted to making the mistakes when they visited the prefectural capital of Akita for a briefing session on June 8. They said actual inspections of many of the sites were never conducted.

The study report, released last month, concluded that the Ground Self-Defense Force’s Araya exercise area in Akita was the suitable site in eastern Japan for deployment of the land-based variant of the U.S.-made Aegis defense system against ballistic and cruise missiles.

The ministry said it had surveyed 19 state-owned plots in Aomori, Akita and Yamagata prefectures as potential alternatives but found that nine were “unfit” because nearby mountains could block radar pulses.

The Akita prefectural government and Akita city government were informed of the findings in May.

Local residents, who are wary of the deployment and had demanded the study on the alternative sites, became further incensed when it was revealed that the study report cited elevation angles of mountain peaks that were larger than the actual figures for the nine candidate sites that were ruled out.

For example, the actual elevation angle of a mountain peak at the site in Oga, Akita Prefecture, was 4 degrees. But it was listed as 15 degrees in the ministry’s report.

According to the ministry, officials who drew up the report produced a cross-section diagram using the virtual globe in the Google Earth Pro app.

But they did not realize that the diagram created was exaggerated vertically to highlight the undulation of the mountains.

They calculated the elevation angles by measuring the distance between the state-owned land and the mountain peaks and the height of the mountains using a scale and trigonometry.

The officials double checked the outcomes with a protractor, but the angles of elevation were larger than they actually were because of the errors created in the original diagrams.

The ministry ruled out alternatives sites if they did not meet the following conditions: nearby mountains must have elevation angles under 10 degrees to prevent interference with radar activities; the site must cover 1,000 square kilometers of flat land; and it must be on the side of the Sea of Japan, rather than the Pacific Ocean.

(This article was written by Mikito Soda and Hayato Jinno.)