Direction Flashcards
Direction
position of one point in relation to another point
required elements of direction
an unerstood base line
an angle measured from that base line
True north
point on earth where lines of longitude converge
true north is not used in order to find direction when doing basic land navigation
Magnetick north
lensatic compass always points to magnetic north
lines not shown on map
used to navigate in the field
Grid North
parallel lines on the map
do not converge at north pole
based on military grid reference system MGRS
Declination
the angular difference between true north and grid north or magnetic north. declination is always measured from true north
azimuth
a horizontal angle measured clockwise from a base line. Can be any of the 3 base lines
2 methods of updaitng the GM angle
Call NGA or USGS.
Use the projected annual magnetic change statement at the bottom of declination diagram
3 methods to for utilizing GM angle and convertingbetween grid and magnetic azimuths
LARS
MAGMGA
Picture method
LARS
is left add right subtract
is used when going from the known azimuth to the uknown
MAGMGA
an equation into which one fills known information and then solves for the unknown
MA+/-GM=GA east add, west subtract
Picture method
drawing diagram on declination
