General Procedure

CNATRAINST 11130.1D

16 June 1999

refers to the Grid Layout Sheet, enclosure (3), which depicts the grid and

allows for entry of the dimensions being used, each station's magnetic

declination, the minimum and the maximum declination of the compass rose and

the mean magnetic declination.

2. The step-by-step procedures for conducting the magnetic survey or certifi-

cation are contained in enclosure (4). These instructions are directly

correlated to the MC-2 Magnetic Certification Sheet, enclosure (5), and the

Station Magnetic Data Work Sheet, enclosure (7). Enclosure (6) contains the

detailed instructions for performing the calculations required on the Station

Magnetic Data Work Sheet.

3. Upon completion of the magnetic survey, azimuth observations must be made

to establish true azimuth control for the grid. If the grid can be easily

tied into an existing triangulation system, such as a prior compass rose

survey which contains the true azimuth of several prominent objects, then the

grid's true azimuth can be determined and the absolute value of declination

can be calculated. If this existing triangulation system is not available,

then a Polaris observation will be required. The instruction for obtaining

true azimuth by Polaris observations are contained in enclosure (8) and are

correlated to the Polaris Observation Data Sheet, enclosure (9).

4. After all of the calculations on the Station Magnetic Work Sheet have been

completed, the declination of each station must be entered on the Grid Layout

Sheet. The minimum and maximum declination must be determined to verify that

the range of declination of the compass rose meets the requirements of MIL-STD

765A, which limits the range to a maximum of twelve (12) minutes. The average

of all of the stations and hubs declination must be taken so that the mean

declination of the compass rose can also be entered.

5. If, after completion of the magnetic survey, it is determined that the

mean declination of the compass rose exceeds that by which the radial markings

are originally laid by more than 1/2 degree the radial lines must be re-laid.

Enclosure (10) provides procedures for re-laying radial lines.

Enclosure (1)