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Monica Spicker Some slides adapted from Harry Frank 2008. USING UTM, MGRS & USNG. Objectives. Understanding UTM system Finding coordinates of a point Plotting a point. NATO system Metric units (meters) World is split into 60, 6º degree zones Spokane area is Zone 11N
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Monica Spicker Some slides adapted from Harry Frank 2008 USING UTM, MGRS & USNG B M O C
Objectives • Understanding UTM system • Finding coordinates of a point • Plotting a point B M O C
NATO system Metric units (meters) World is split into 60, 6º degree zones Spokane area is Zone 11N Distorted above North 84º, and South 80º, not applied above these latitudes. Smallest grid unit on USGS 1:24000 maps is 1 km. May be different on different scale maps! Coordinates get larger going east (easting) from the zone meridian and larger going north (northing) from the equator. Universal Transverse Mercator (UTM) B M O C
Identifying the grid 466 467 (Easting) 5157 5157 Map 5156 5156 (Northing) 466 467 B M O C
5157 5156 Determining Coordinates: Easting Determine the easting first: From the object on map ( ) go to the bottom (or top) edge of the map Find the nearest smaller coordinate to the LEFT (W) of your point 465 466 B M O C
Determining Coordinates: Easting B M O C
Determining Coordinates: Easting Divide the distance between the coordinate to the left of your point and the coordinate to the right of your point into tenths 3tenths This is hundreds of meters 465 466 B M O C
Determining Coordinates: Easting B M O C
5156 5157 466 465 Determining Coordinates: Northing Find the nearest coordinate below (S) of your point From the point on map ( ) look to the left (or right) edge of the map B M O C
5157 5156 Determining Coordinates: Northing Count or estimate the number of tenths from the coordinate BELOW your point TO the corner. This is hundreds of meters 8Tenths B M O C
Final Coordinates of 465300E 5165800N But we can go finer, if we use a template B M O C
Starting corner: 465000E 5165000N Template placed on map at kilometer grid corner Using a Template • Must match map scale! • Can estimate how far into box on a scale of 1 to 10 to find nearest ten meters. 5165820N 465360E B M O C
Starting corner: 465000E 5165000N Another Way to Use the Template • Put the 0 corner of the template on the point. • Read where the block margin hits the template scales. 465360E 5165820N B M O C
Determining Coordinates 489520E 5315440N Start here. 489000E, 5315000N B M O C
Practice Exercises B M O C
Plotting Points • Underline the last 3 digits of each coordinate. • What’s not underlined are the margin coordinates. Example: 490150E 5315325N Use template to determine position within the kilometer box. B M O C
Start here. 490, 5315 Plotting 490120E 5315340N 490120E 5315340N B M O C
Practice Exercises B M O C
Military Grid Reference System US National Grid System USNG and MGRS are identical Based on UTM Default datum is NAD83 Includes UTM zone (number and letter) A two letter grid designator that replaces the smaller written UTM number in the margin only the ending 5 numbers. More can be truncated, if you are not going down to single meters. Most GPS support MGRS. Most commercial maps do NOT. MGRS and USNG B M O C
Example in UTM: 11T 490150E 5315325N in MGRS: 11T MP 90150E 15325N NAD83 : 1 meter 11T MP 9015E 1532N NAD83 : nearest 10 meters 11T MP 901E 153N NAD83 : nearest 100 meters B M O C