SUBCOURSE EDITION - Modern Prepper

(1) First, determine the correct spheroid, and obtain the tables prepared for that spheroid(TM 5-240, app A).(2) Determine the geographic values of the 5-minute intersections needed to complete theprojection. Figure 4-7 illustrates the geographic coordinates of a hypothetical 1:50,000 scale sheet whichfalls in the area covered by the International Spheroid, requiring the use of TM 5-241-13. The crossedticks in the figure indicate the 5-minute intersections which must be computed and plotted. The circledticks indicate the four sheet corners plotted from the grid computations.Figure 4-7. Geographic coordinates and 5-minute intersections, 1:50,000 scale.(3) Determine the central meridian of the zone in which the sheet falls. In this case, it is9E. The central meridian is noted on the grid computations.(4) To find the grid coordinates of the first 5-minute intersection to the right of the SWcorner, on the lower edge of the sheet (48° 30'N 8° 20'E) we turn to the page in TM 5-241-13 whichgives us the figures for latitude 48°30'. This page is reproduced in figure 4-8.139