Revision of elevations of Japan’s main mountains

 On April 1, Geospatial Information Authority of Japan (GSI) revised the elevation values in the “Catalog of Japan’s Mountain Elevations - 1,003 Mountains”, which lists the elevations of Japan’s main mountains.

 This revision was to update the elevation results of triangulation points throughout Japan, based on the development and spread of new survey technologies such as GNSS surveys.

 The “Catalog of Japan’s Mountain Elevations - 1,003 Mountains” is compiled by GSI based on results from basic survey such as 1:25,000 topographic map, having conducted inspections and supplementary survey regarding the names of Japan’s main mountains and the position/elevation of their highest points. The elevation values of the highest sites are either the elevations of triangulation points or the values measured by means of photogrammetry or field survey.
 On April 1, the elevation values (in units of m) in the “Catalog of Japan’s Mountain Elevations - 1,003 Mountains” were revised in accordance with the nation-wide revision of elevation results of triangulation points.
 From this, of the 1,003 mountains, 48 had their elevation values changed by +1m and 39 by -1m.
The “Catalog of Japan’s Mountain Elevations - 1,003 Mountains” can be browsed from the following website (Japanese only).
http://www.gsi.go.jp/KOKUJYOHO/MOUNTAIN/mountain.html

About revision of elevation results of triangulation points

 GSI has established and maintained horizontal control network for land survey in Japan, which is consisted of triangulation points and GNSS-based control stations. The horizontal coordinates and elevations of the triangulation points are published as survey results.  On April 1, GSI revised the elevation results of these triangulation points, and ensured consistency of elevations between the triangulation points and control points based on GNSS-based control stations.
 

What is GNSS?

 A general term for space-based PNT (Positioning, Navigation, and Timing) system determining positions by using signals from satellites, which includes GPS, GLONASS, Galileo, and the Quasi-Zenith Satellites.