Declination Diagram
An azimuth is defined as a horizontal angle measured clockwise from a north base line. This north base line could be true north, magnetic north, or grid north. The azimuth is the most common military method to express direction. When using an azimuth, the point from which the azimuth originates is the center of an imaginary circle . This circle is divided into 360 degrees or 6400 mils . NORTH IS 0/360 AZIMUTH EAST IS 90. SOUTH IS 180. WEST IS 270.
As the request is for the back azimuth, then what is wanted is the reverse (or inverse) of the azimuth, 223 degrees. In other words, an object moved in the direction of 223 degrees (Southwest relatively), but now the desire is to reverse the travel in order to arrive at the starting point. (That starting point would have to be Northeast relatively.) One does not typically work with directions exceeding 360 degrees nor less than 0 degrees as that range is the range of a compass. Therefore, the back azimuth of 223 degrees, whatever it is, must be between zero and 360 degrees. To determine the back azimuth all that is necessary is the knowledge that 1) the back azimuth is the opposite direction of the azimuth and 2) 180 degrees either added or subtracted will yield the back azimuth, and 3) the correct back azimuth must be in the range of zero to 360 degrees. Given this knowledge and the variable definitions Ab = Back Azimuth and A = Azimuth, Ab = A + 180 or Ab = A - 180 But which equation yields the correct back azimuth? Using knowledge point #3 above, the correct result will be the one that is between zero and 360 degrees. Therefore, Ab = A - 180 = 223 - 180 = 43 degrees is the correct back azimuth. The other choice, Ab = A + 180 = 223 + 180 = 403 degrees, exceeds the range of the compass, so 403 degrees cannot be the correct back azimuth.
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on a hundredths grid 7 hundredths is 7; but seven tenths is 0.7 which is 70 hundredths. So 7 tenths would be 70 on the hundredts grid, separating it from 7 hundredths
Declination Diagram
If converting from grid to magnetic you subtract, if converting from magnetic to grid you add.
You would use a protractor or a compass to determine a grid azimuth on a map. These tools help you measure the angle between a grid line and the north direction on the map, providing the azimuth reading.
An azimuth is defined as a horizontal angle measured clockwise from a north base line. This north base line could be true north, magnetic north, or grid north. The azimuth is the most common military method to express direction. When using an azimuth, the point from which the azimuth originates is the center of an imaginary circle . This circle is divided into 360 degrees or 6400 mils . NORTH IS 0/360 AZIMUTH EAST IS 90. SOUTH IS 180. WEST IS 270.
Establish true North and grid North.
plot the points
Military protractor
Military protractor
The azimuthal grid is a coordinate system that stays still while the stars move across it on the sky (the celestial sphere). It measures the altitude above the horizon and the azimuth (position along the horizon) of the celestial object at a particular time, for a particular place.
The azimuthal grid is a coordinate system that stays still while the stars move across it on the sky (the celestial sphere). It measures the altitude above the horizon and the azimuth (position along the horizon) of the celestial object at a particular time, for a particular place.
The angle between the direction your compass points and the direction you're facing is the 'magnetic azimuth'. The angle between the direction to the north pole and the direction you're facing is the 'true azimuth'. They are virtually never the same angle. The difference between them is the 'magnetic declination' or the 'compass declination' in the place where you are at in which.
An azimuth originates from the North point, typically referencing true North or magnetic North depending on the context. It is measured in degrees clockwise from North, ranging from 0° to 360°.