Test of Map-Read Magnetic Declination Accuracy.

摘要

This report covers a test of how accurately a map-referenced magnetic declination represents the actual magnetic declination found by measuring true north and magnetic north at various points selected at random within the mapped area. The undeveloped area in Quantico, Virginia was investigated and found to have individual variations as great as 23 mils, with a 1-sigma standard deviation of 8 mils from the map-read value. (Author)