Handling of the relationship between magnetic north and true north

　According to the results of the 2000 measurement by the Geographical Survey Institute of the Ministry of Land, Infrastructure, Transport and Tourism, the difference between the magnetic north and true north in most city areas is 7 degrees, and the magnetic polarization in the city is 7 degrees as standard. I will do it.
　In addition, regardless of the above magnetic polarization angle, it may be possible to determine the true north direction based on actual measurement of the solar position or basic map of city planning <topographic map>.
　The application start date is December 1, 2007.
※When determining the direction angle by on-site measurement, it is necessary to pay attention to the consistency with the city planning basic map <topographic map>.