What is the 250m-mesh code?
250m-mesh code is a part of the divided grid square code defined by JIS X 0410/AMENDMENT1:2002.
A 250m-mesh is a square area of 7.5 arc-seconds latitude x 11.25 arc-seconds longitude (about 250m x 250m). This geographical coordinate system adopts the standard grid square (mesh code N) based on Tokyo Datum.
Please refer to “Statistics Bureau : Standard Grid Square and Grid Square Code Used for the Statistics 2.(2)B.” for details.