протрактор для орієнтування карти за схиленням
protractor scale
artillery board protractor
bevel protractor
protractor
celluloid protractor
declination
declination diagram
magnetic declination
declination aiming circle (declinated aiming circle)
declination chart
declination index
declination pin
angle of declination
magnetic variation / magnetic declination
map declination
grid declination
declination constant
declination statement
declination station