SUBCOURSE EDITION - Modern Prepper

(1) The top line of each section is the "station" identification for the point. This is used bythe surveyor when converting the coordinates of geodetic control, and will be left blank when the formis used to record graticule ticks.(2) Just below the "station" block is the geographic value for the graticule tick. Thegeographic values are recorded in the same manner as on DA Form 1941. ∅ (phi) is the latitude value(line running east-west), and λ (lambda) is the longitude value (line running north-south).(3) The next seven lines are used by the topographic surveyor to enter the computational dataused to convert the geographic value to a UTM value. Since most computing is now done oncalculators, this section is usually left blank.(4) The last line of each section is the northing (N) and easting (E) UTM grid equivalents ofthe geographics. These are the values you will use to plot the graticule tick.(5) By examining figure 3-8 you can determine that the UTM grid equivalents of the graticuletick 38° 30' west latitude, 77° 25' north longitude is 4263854.29 meters, north; 289252.26 meters, east.To plot this graticule tick, we must convert the UTM grid value to an easily measurable distance. Theconversion factor (.002), listed on DA Form 1941, will be used to convert the grid values. This isaccomplished by multiplying the grid values by the conversion factor.(6) To convert the UTM coordinates you need to examine each grid value separately. Youwill start with the northing value 4263854.29 meters, first. This northing coordinate says that thelatitude value of the graticule tick is 4,263,854.29 meters north of the equator. We know that 1,000meter northing grid values are expressed by four digit numbers. Therefore, the first four digits of thenorthing value represents the 4263 grid line. The latitude value of the graticule tick is 854.29 metersfrom the 4263 grid line (fig 3-9).(7) Since you cannot accurately plot ground distance on a map, you must convert thisdistance to a measurable increment. Since the grid was constructed using centimeters, you will usecentimeters as the measuring increment. To accomplish this, simply multiply 854.29 meters by thyconversion factor (.002). Therefore, the latitude value of the graticule tick is 1.709 centimeters above the4263 grid line (fig 3-9).53