2:30 PM - 2:45 PM
[SEM13-04] Analyzing the early 19th century's geographical points in latitude and longitude of 0.2 second level and geomagnetic declination through Japan from Tadataka Inoh's magnetic survey azimuth ledger simultaneously.
Keywords:Tadaataka Inoh, geomagnetic declination, inter disciplinary analysis
The Santou-Houi-Ki is a national tresure of Japan recorded by cartographer Tadataka Inoh in 1800 to 1816 consist of 67 volumes magnetic survey azimuth ledger of Japan. In the Santou-Hou-Ki estimate 200,000 magnetic compass survey azimuth data by acculacy of 0 degree 05 minute unit were recrded with name or short description of magnetic compass survey excution reference point and target points . Inoh carried out the survey did not aplly the correction of magnetic declination<in Edo(ToKyo) was nearlyzero. It is able to calculte backward the precise position of survey excution reference point,where the value of geomagnetic declination,subtracting the magnetic survey azimuth from the true azimythto any target points are similar or approximate by using exce formula. Check the sourse books or maps of local history,and adjust the precise detail position. We must excute interdisciplinary and simultaneous analysis. This time,I will mention the transition of the geomagnetic declination in Nagasaki in the first half of the 19th century.