DMA TECHNICAL MANUAL 8358.1



Datums, Ellipsoids, Grids, and Grid Reference Systems

TM 8358.1 Sections 6-7 through 8-6


6-7 THE DECLINATION DIAGRAM (MORE THAN ONE GRID).

6-7.1 When a sheet bears more than one major grid, or major and overlapping grids, a separate diagram appears for each grid shown on the map. Declination data are not shown for secondary grids. Figure 22 illustrates the declination data shown on a sheet which contains more than one grid.

6-7.2 The grid north prong of each diagram is aligned with the easting (vertical) grid lines or grid ticks of the grid to which it pertains. No connection is shown between the grid north prong and any grid line or grid tick.

6-7.3 The composition of each diagram is the some as described in paragraph 6-6, except:

6-7.3.1 The diagram is miniaturized, and the three prongs are shown as full lines of the same length.

6-7.3.2 The minimum plotted angle between any two prongs is three degrees with relative symmetry maintained.

6-7.3.3 Each diagram bears the identification of the grid to which it pertains.

6-7.3.4 Each diagram and its related notes are printed in the same color as the grid values to which they pertain.

6-8 THE GRID REFERENCE BOX.

6-8.1 A grid reference box appears in the margin of each sheet. The box contains instructions and attendant data to enable the user to compose standard grid references.

6-8.2 The grid system(s) in use on the map dictates the referencing instructions contained in the grid reference box. The grid reference boxes most commonly used on maps, 1:100,000 scale and larger, are illustrated in figure 23. The boxes are subject to modifications.

6-8.3 The grid reference box also contains diagrams identifying applicable grid zone designations and grid square identifications.

Figure 22. The Declination Data when a Sheet Contains an Overlapping Grid and/or More Than One Major Grid.

6-8.3.1 For the UTM and UPS grids, the diagrams show the grid zone designation, the l00,000-meter grid lines and their values in abbreviated form, and the 100,000-meter square identifications). Figure 24 illustrates the composition of the diagrams under various conditions.

6-8.3.2 For nonstandard grids, the diagram shows the 100,000-unit square identifications and the values of the 100,000-unit grid lines in abbreviated form. These data are printed in the same color as the grid values to which they pertain. If the grid system identifies larger squares, their identifications are shown in smaller type just preceding the 100,000-unit identifications. The 100,000-unit grid lines and grid junction lines are printed in black (blue at 1:100,000 scale). If a junction is a grid line, its value Is shown in abbreviated form and printed in the same color as the grid values to which it pertains. Loxodromes are not labeled. Figure 25 illustrates the composition of this information under various conditions.

Figure 23. Grid Reference Boxes Most Commonly Used on Maps at Scales of 1:100,000 and Larger.

Figure 24. Methods of Showing Grid Zone Designations and 100,000-meter Squares of the UTM in the Grid Reference Boxes of Large Scale Maps

6-8.3.3 For sheets that have a land inset whose l00,00-unit square identification letters differ from those of the map proper, the identification letters are shown in the interior of the inset, rather than in the grid reference box.

6-8.4 When more than one major grid appears on a sheet and the method for giving a reference is the same for all the grids, a common reference box is used.

6-8.5 When more than one major grid appears on a sheet and the method for giving a reference varies with the grids, circumstances control the treatment of the grid reference boxes.

6-8.5.1 A grid reference box is shown in the margin for each grid. Over each box appears a note limiting the use of the box to the grid or grids concerned.

6-8.5.1.1 When each box describes the method of referencing for one grid only, the note is printed in the same color as the values for its respective grid and is modeled after the following:

USE THIS BOX FOR GIVING REFERENCES ON THE
UNIVERSAL TRANSVERSE MERCATOR GRID       

USE THIS BOX FOR GIVING REFERENCES ON THE
MADAGASCAR GRID                          
        
    

Figure 25. Methods of Showing 100,000-unit, and Larger, Square Identifications of Nonstandard Grids in the Grid Reference Boxes of the Large Scale Maps.

6-8.5.1.2 When the same system of referencing is used for two grids occurring in the same sheet with a third grid which uses a different reference system, the note for the common reference box is printed in black and modeled after the following:

USE THIS BOX FOR GIVING REFERENCES ON THE
SUD ALGERIE AND SUD TUNISIE GRIDS        
    

6-8.5.2 When all reference boxes cannot be accommodated in the margin, the excess is shown in expanses of open water on the face of the map. When this is not practicable, a note which refers the user to an adjacent sheet is added to a reference box in the margin. The notes are modeled after the following:

USE THIS BOX FOR GIVING REFERENCES ON THE  
UNIVERSAL TRANSVERSE MERCATOR GRID         

SEE SHEET 3987 I FOR GIVING REFERENCES ON  
THE NORD MAROC GRID                        
        
USE THIS BOX FOR GIVING REFERENCES ON THE  
UNIVERSAL TRANSVERSE MERCATOR GRID         

SEE SHEET 1285 III FOR GIVING REFERENCES ON
THE SUD ALGERIE AND SUD TUNISIE GRIDS      
    

CHAPTER 7 PORTRAYAL OF GRIDS ON MAPS AT 1:250,000 AND 1:500,000 SCALE


7-1 GENERAL.

7-1.1 Grid data and grid format for maps at scales of 1:250,000 and 1:500,000 are essentially the same for Universal Transverse Mercator grids, Universal Polar Stereographic grids, and nonstandard grids. When possible, sheet lines of maps at these scales are planned to coincide with grid junctions and ellipsoid junctions.

7-1.2 Grids added on reprints of maps of other origin adhere as closely as possible to these standards. There may be minor changes in limits of grid zones and variations in the color of grid lines and grid values. The changes and variations or are explained, as necessary, in the margin of the map.

7-1.3 The grid data consist of grid lines and values, grid reference boxes, notes identifying the grids, and notes giving the range of magnetic declination over the sheet. Overlapping and extended grids are not shown.

7-1.4 Descriptions and illustrations are keyed to 1:250,000 scale, unless otherwise indicated. Specific dimensions, size and style of type, and placement of margin data relating to grids and grid formats at 1:250,000 scale are shown on DMA style sheets.


7-2 THE MAJOR GRID.

7-2.1 The major grid is shown by full lines printed in blue, at 10,000-unit intervals. The unit is predominately meters; yards are used for some nonstandard grids. Every 100,000- unit grid line is accentuated in weight and definitive designations are shown at their intersections in the map interior.

7-2.2 Grid values appear outside the neatline on all four sides of the sheet, labeling each grid line.

7-2.3 Where a grid line coincides with a neatline of the map, the grid line is omitted but the neatline is labeled with the values for the grid line. Except for the values labeling the first grid line in each direction from the southwest corner of the sheet, the last four digits (0000) of the values are omitted. The values are shown in two sizes of type, with the larger size being reserved for the principal digits.

7-2.3.1 With most grids, one principal digit is used. This represents the 10,000 digit of the grid values.

7-2.3.2 Two principal digits are used with the Madagascar grid, the Lambert grids of northwest Africa, and the Ceylon Belt. These represent the 100,000 and 10,000 digits of the grid values.

7-2.4 At 1:250,000 scale, a grid ladder is shown in the interior of the map. The grid ladder is an established pattern of columns and rows of grid values, expressed in principal digits only. Positioning of the columns and rows is illustrated in figure 26. In areas of dense detail, a ladder number may be moved along a grid line a maximum of one-fourth of the grid interval, or omitted if it impairs legibility of map detail. Omissions are held to a minimum.

Figure 26. Treatment for the Major Grid in UTM Areas as Shown on a 1:250,000 Map.

7-2.4.1 At the intersection of two 100,000-unit grid lines, the appropriate unit square identification letters are always shown. When this intersection coincides with a neatline, only those identification letters failing inside the neatline are shown. Identification letters are similarly shown inside the neatline  when the intersection of a 100,000-unit line with a grid or ellipsoid junction line coincides with a neatline. Both sides of the neatline to the north and east on a Joint Operations Graphic (JOG) should be labeled, however, to show the different identification in the overlap area.

7-2.4.2 For nonstandard grids which identify 100,000-unit and 500,000-unit squares, the 500,000-unit identification letter appears in smaller size immediately before the 100,000- unit square identification letter.

7-2.5 At the 1:500,000 scale, the grid ladder is designed to treat each specific 100,000- unit square. Figure 27 illustrates the treatment. Note the relationship of the ladder to the accentuated 100,000-unit lines. For non-standard grids which also identify larger grid squares - such as the 500,000-unit squares - the additional identifications appear in smaller type immediately before each 100,000-unit square identification.

7-2.6 The color of the grid values and ladder values is governed by the grid system.

7-2.6.1 Blue is used when the grid system is either the Universal Transverse Mercator or the Universal Polar Stereographic.

Figure 27. Treatment for the Major Grid in UTM Areas as Shown on Maps Smaller than 1:250,000 Scale and Larger than 1:100,000

7-2.6.2 With nonstandard grids, the color varies - black, blue, or red-brown - as specified in Chapter 4. Sheets with nonstandard grids adhere to these color conventions. (For a JOG, black is substituted for red.)

7-2.7 A grid note printed in the same color as the values for the major grid appears in the lower margin of each sheet to identify the grid. The note is modeled after the following:


BLUE NUMBERED LINES INDICATE THE 10,000 METER     
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE 53,      
BESSEL ELLIPSOID                                  

RED-BROWN NUMBERED LINES INDICATE THE 10,000 METER
MADAGASCAR GRID, INTERNATIONAL ELLIPSOID          
        
BLACK NUMBERED LINES INDICATE THE 10,000 METER    
BRITISH NATIONAL GRID, AIRY ELLIPSOID             
    

7-2.7.1 On sheets having land insets for which the grid or grid zone differs from that of the map proper, the appropriate grid note is shown within the inset. (A JOG does not have insets.)

7-2.7.2 On maps with nonstandard grids, in addition to identifying the interval, grid, and ellipsoid, the note usually describes the projection, origin, false coordinates of the origin, and the scale factor of the grid.


7-3 MULTIPLE MAJOR GRIDS.

7-3.1 In certain instances a sheet contains more than one major grid.

7-3.1.1 With the UTM and UPS grids this may occur:

7-3.1.1.1 Where a sheet is shifted from the normal position to avoid making additional sheets.

7-3.1.1.2 In higher latitudes, where sheets may be wide in longitudinal extent.

7-3.1.1.3 At datum junctions.

7-3.1.2 With nonstandard grids, this condition occurs more frequently since grid junctions are sometimes loxodromes or are grid lines not coincident with parallels or meridians.

7-3.2 Grid, datum, ellipsoid, and zone junctions are indicated by accentuated lines printed in blue. Labels may appear on each side of the junction line. The labels may be shown more than once to facilitate identification. Each label is printed in the color designated for the particular grid system. Where a grid, datum, ellipsoid, or zone junction line is coincident with a neatline, both the junction line and the identifying labels are omitted.

7-3.2.1 For nonstandard grids, the label is modeled after the following:

BRITISH NATIONAL GRID
NORD ALGERIE GRID    
MADAGASCAR GRID      

7-3.2.2 The label for a UTM grid junction, or a UPS grid junction, includes the identification of the Grid Zone Designation and is written in MGRS terms as:


UTM GRID ZONE DESIGNATION: 47T
UPS GRID ZONE DESIGNATION: B  

7-3.3 Each grid is shown by full lines within its own area only, being represented in the normal manner at 10,000-unit intervals with every 100,000-unit line accentuated in weight. All grid lines are printed in blue.

7-3.4 Grid values appear on all four sides of the sheet (outside the neatline) labeling each grid line. The composition of the number is similar to that described in paragraph 7-2.3, except that full grid values label the first grid line in each direction from each corner of the sheet.

7-3.5 On maps at l:250,000 scale, the grid ladder values are shown as described in paragraph 7-2.4. Departures in labeling are often necessary when two or more major grids are shown. At least one row and one column of identifications are shown within the areal extent of each grid; the normal labeling plan is followed when practical.

7-3.6 Where appropriate for the grid, at 1:250,000 scale, identification of 100,000-unit squares and larger unit squares appear on the face of the map at all 100,000-unit grid line intersections as described in paragraph 7-2.4. The unit-square identifications appear in the some color as the grid values.

7-3.7 The colors of the grid values vary with different grids.

7-3.7.1 The UTM and UPS grid values are shown in blue when either grid appears alone or with another grid. When both the UTM and UPS grids appear on the same sheet, the grid values are shown in blue for whichever of the two grids occurs most frequently on the sheets in the general area. The values for the other grid are shown in red-brown.

7-3.7.2 For nonstandard grids, the values appear in the colors specified for the grid system as described in paragraph 7-2.6.2. Where the designated colors are the same, one or more substitutions are made to emphasize distinction. Usually, the conventional color is retained for the grid which occurs most frequently on the sheets in the general area. In general, the order of preference is black, blue, red-brown. (For a JOG, black is substituted for red.)

7-3.7.3 Blue usually is used for the UTM or UPS grids when either appears in combination with nonstandard grids. In such cases, if the conventional color for a nonstandard grid is blue, a substitution is made for the nonstandard grid with black or red-brown being used.

7-3.8 Notes identifying each grid appear in the lower margin of the sheet. These are printed in the same color as that used for the values for the grid each identifies.

7-3.8.1 When the grids are different zones of the UTM grid, the note is modeled after the following:


BLUE NUMBERED LINES INDICATE THE 10,000 METER
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE 50  
AND 51, CLARKE 1866 ELLIPSOID                

7-3.8.2 When more than one grid is involved, the notes are modeled after the following:


BLUE NUMBERED LINES INDICATE THE 10,000 METER     
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE 37,      
INTERNATIONAL ELLIPSOID                           

RED-BROWN NUMBERED LINES INDICATE THE 10,000 METER
UNIVERSAL POLAR STEREOGRAPHIC GRID, NORTH,        
ZONE Z, INTERNATIONAL ELLIPSOID                   

BLUE NUMBERED LINES INDICATE THE 10,000 METER     
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE 37,      
CLARKE 1880 ELLIPSOID                             

RED-BROWN NUMBERED LINES INDICATE THE 10,000 METER
MADAGASCAR GRID, INTERNATIONAL ELLIPSOID          

7.3.8.3 A separate marginal note is not shown for the grid in the north or east overlap of a JOG. Such a grid is identified on the face of the map only.

7-3.9 Figures 28 and 29 illustrate these principles.

7-3.10 When an ellipsoid junction occurs on a map sheet, the UTM grid treatment is the same as that followed when a sheet straddles a grid junction. The ellipsoids are identified on each side of the junction line. See figure 30. A note, printed in the same color as the grid values, appears in the lower margin of the sheet identifying the grids, zone(s), and ellipsoids.


BLUE NUMBERED LINES INDICATE THE 10,000 METER
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE 52, 
WGS ELLIPSOID, AND ZONE 52, BESSEL ELLIPSOID 

7-3.11 In certain cases, a sheet bearing the UTM grid may straddle a parallel which marks the division between different grid zone designations. The grid and corresponding labeling appear as previous described. A continuous line in black indicates the dividing parallel. The proper grid zone designations, printed in the same color as the grid values, appear on each side of the line. The dividing parallel is omitted when it falls within 2.5 mm (0.10inch) of the north or south neatlines. Figure 31 illustrates these principles.


7-4 OVERLAPPING AND EXTENDED GRIDS

Overlapping and extended grids are not shown on maps at these scales.


7-5 SECONDARY GRIDS

7-5.1 Secondary grids are seldom shown on JOGs. As a general rule, secondary grids are no longer required on military topographic maps. Excepted are those instances where mapping arrangements with cooperating foreign agencies specify the showing of a secondary grid. No more than one secondary grid is shown.

7-5.2 When required, the secondary grid is shown by inside ticks, printed in blue, emanating from the neatline in their correct alignment and spaced at 10,000-unit intervals. The even 100,000-unit ticks are accentuated in weight.

7-5.3 Values, similar in composition to those labeling the major grid lines, appear on all four sides of the sheet. The first grid tick in each direction from the southwest corner of the sheet is labeled with full values. Thereafter, only those grid ticks whose values are multiples of 50,000 are labeled. If the secondary grid is a nonstandard grid, prescribed colors are used (para. 7-1.6-2), unless there is conflict with another grid shown on the map. In that event, substitutions are made in the established order of preference.

Figure 28. Two Major Grid Zones Separated by a Grid Junction as Shown on a 1:250,000 Scale Map.

7-5.4 A grid note, identifying the secondary grid, appears in the lower margin of the sheet. It is printed In the some color as that used for the values of the grid it identifies and is modeled after the following:

BLACK NUMBERED TICKS INSIDE THE NEATLINE
INDICATE THE 10,000 METER LEVANT ZONE   
GRID, CLARK 1880 ELLIPSOID              
    

7-5.5 The principles outlined above are illustrated in figure 32.

7-5.6 If a sheet includes areas of more than one secondary grid, only one secondary grid is shown. This is extended over the entire sheet. Usually, the secondary grid shown is that which covers the major portion of the sheet. If the sheet is divided equally by more than one secondary grid, the one shown is that which occurs on most of the sheets in the area.

Figure 29. Three Major Nonstandard Grids Separated by Grid Junctions as Shown on a 1:250,000 Scale Map.


7-6 GRID DECLINATION.

Grid declinations from, true north are not shown on maps at these scales.


Figure 30. Two Major Grid (UTM) Separated by an Ellipsoid Junction as Shown on a 1:250,000 Scale Map.

7.7 MAGNETIC DECLINATION.

7.7.1 In the margin of each sheet a note is shown to give the magnetic declination, usually for the centers of the west and east edges of the sheet. The declination is expressed to the nearest 1/2 degree, with mil equivalents to the nearest 10 mils.

7-7.1.1 The declination is obtained from the latest isogonic data for a standard epoch (i.e., a year that is divisible by five, such as 1990, 1995).

7-7.1.2 No reference is made to the annual magnetic change.

7-7.2 The note is usually printed in purple and is modeled after the following:

Figure 31. Treatment when Grid Falls within More than One UTM Grid Zone Designation Area Shown on a 1:250,000 Scale Map.


1990 MAGNETIC DECLINATION FROM TRUE  
NORTH VARIES FROM 1 1/2° (30 MILS)   
WESTERLY FOR THE CENTER OF THE WEST  
EDGE TO 2° (40 MILS) WESTERLY FOR THE
CENTER OF THE EAST EDGE              

7-7.3 On sheets where the declination Is the same over the entire sheet, the note is modeled after the following:


MAGNETIC DECLINATION FOR 1990 IS
1 1/2° (30 MILS)                
WESTERLY OVER THE ENTIRE AREA   

Figure 32. Major and Secondary (Obsolete) Grids as Shown on a 1:250,000 Scale Map.

Figure 33. Grid Reference Boxes Most Commonly Used on Maps at 1:250,000 and 1:500,000 Scale.

7-7.4 On the Air version of the JOG, isogonic lines (lines of equal magnetic variation) are shown on the face of the sheet in place of the magnetic declination note in the margin. In addition to the isogonic lines, a note modeled after the following is shown in the margin:


LINES OF EQUAL MAGNETIC VARIATION FOR 1990
(Annual rate of change, no change)        

7-7.5 If there are less than two 15 minute isogonic lines, the magnetic variation is shown by a note modeled after the following:


MAGNETIC VARIATION FOR 1990 IS APPROXIMATELY
1° W OVER THE ENTIRE AREA                   
(Annual rate of change 7' decrease)         

7-8 THE GRID REFERENCE BOX.

7-8.1 A grid reference box appears in the margin of each sheet. The box contains step-by-step instructions for composing a grid reference. For examples, see figure 33. The applicable grid zone designation is also identified in the box.

7-8.2 The grid system(s) in use on the map dictates the referencing instructions contained in the grid reference box.

7-8.3 When more than one major grid appears on a sheet and the method for giving a reference is the same for all the grids, a common reference box is used.

7-8.4 When more than one major grid appears on a sheet and the method for giving a reference varies with the grids, circumstances control the treatment of the grid reference boxes.

7-8.4.1 A grid reference box is shown in the margin for each grid, except those failing completely in open water area. Over each box appears a note limiting the use of the box to the grid or grids concerned.

7-8.4.1.1 When each box describes the method of referencing for one grid only, the note is printed in the same color as the values for its respective grid and is modeled after the following:


USE THIS BOX FOR GIVING REFERENCES ON THE
UNIVERSAL TRANSVERSE MERCATOR GRID       

USE THIS BOX FOR GIVING REFERENCES ON THE
MADAGASCAR GRID                          

7-8.4.1.2 When the same system of referencing is used for two grids occurring on the same sheet along with a third grid using a different reference system, the note for the common reference box is printed in blue and modeled after the following:


USE THIS BOX FOR GIVING REFERENCES ON THE SUD
ALGERIE AND SUD TUNISIE GRIDS                

7-8.4.2 When all reference boxes cannot be accommodated in the margin, the excess is shown in expanses of open water on the face of the map. When this is not practicable, a note which refers the user to an adjacent sheet is added to a reference box in the margin. This note is positioned below the note described in paragraph 7-8.4.1.2, above. If only one grid is involved, the note is printed in the same color as the values for that grid. If more than one grid is involved, the note is printed in blue. The notes are modeled after the following:


USE THIS BOX FOR GIVING REFERENCES ON THE  
UNIVERSAL TRANSVERSE MERCATOR GRID         

SEE SHEET NI 30-06 FOR GIVING REFERENCES ON
THE NORD MAROC GRID                        

USE THIS BOX FOR GIVING REFERENCES ON THE  
UNIVERSAL TRANSVERSE MERCATOR GRID         

SEE SHEET NI 32-10 FOR GIVING REFERENCES ON
THE SUD ALGERIE AND SUD TUNISIE GRIDS      

CHAPTER 8 PORTRAYAL OF GRIDS ON MAPS AT 1:1,000,000 SCALE


8-1 GENERAL.

Grid data and grid format for maps at 1:1,000,000 scale generally appear as described in this section. Except for minor differences, the design is essentially the same for Universal Transverse Mercator grids, Universal Polar Stereographic grids, and nonstandard grids. The maps usually show grid lines and ticks, their values, grid letters, and notes in the margin identifying the grid and the grid zone designation. Variations in the specifications for particular types of products at 1:1,000,000 scale exist. The individual product specifications must be followed. A typical treatment is shown in figure 34.


8-2 THE MAJOR GRID.

8-2.1 The major grid is shown by full lines at 100,000-unit intervals, intersected by ticks at 10,000-unit intervals. Where a grid line coincides with a neatline of the map, the grid line and its intersecting ticks are omitted. However, the neatline is labeled in the margin with the values for the grid line.

8-2.2 Grid values appear outside the neatline on all four sides of the sheet, labeling each grid line. They may also label only the first grid line in each direction from the southwest corner. Except for the values labeling the first grid line in each direction from the southwest corner of the sheet, the last four digits (0000) of the values are omitted. The values are shown in two sizes of type, with the larger size being used for the principal digits.

8-2.2.1 With most grids, one principal digit is used. This represents the 10,000 digit of the grid values.

8-2.2.2 Two principal digits are used with the Madagascar grid and the Lambert grids of northwest Africa, and the Ceylon Belt. These digits represent the 100,000 and 10,000 digits of the grid values.

8-2.3 When the grid system is one which identifies its 100,000-unit squares, the identifications appear on the face of the map, centered within the appropriate squares. For nonstandard grid systems which also identify larger grid squares - such as the 500,000- unit squares - the additional identifications appear in smaller type immediately before each 100,000-unit square identification.

8-2.4 Blue is used for all grid information, including grid lines, grid ticks, 100,000-unit square identifications, grid values, and all margin grid information.

8-2.5 A note printed in blue appears in the lower margin or in the legend of each sheet to identify the grid and the full grid zone designation. The note is modeled after the following:


BLUE TICKS AT 100,000 METER INTERVALS AND BLUE
TICKS AT 10,000 METER INTERVALS INDICATE THE  
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE      
DESIGNATION 37T, INTERNATIONAL ELLIPSOID      

BLUE LINES AT 100,000 METER INTERVALS AND BLUE
TICKS AT 10,000 METER INTERVALS INDICATE THE  
MADAGASCAR GRID, INTERNATIONAL ELLIPSOID      

Figure 34. Treatment for the Major Grid in UTM Areas Shown on Maps at 1:1,000,000 Scale.

8-2.6 On maps having land insets for which the grid or grid zone differs from that of the map proper, the appropriate grid note is shown within the inset.


8-3 MULTIPLE MAJOR GRIDS.

8-3.1 In many instances a sheet contains more than one major grid. This occurs especially in higher latitudes, where sheets may be wide in longitudinal extent, and in areas covered by nonstandard grids, where grid junctions are not necessarily coincident with parallels or meridians.

8-3.2 Grid, datum, ellipsoid, and zone junctions are indicated by accentuated lines, printed in blue. Labels appear on each side of the junction line. The labels may be shown more than once to facilitate Identification. Where a grid, datum, ellipsoid, or zone junction line is coincident with a neatline, both the junction line and the identifying labels are omitted.

8-3.2.1 For nonstandard grids, the label Is modeled after the following:


BRITISH NATIONAL GRID

MADAGASCAR GRID      

8-3.2.2 The label for a UTM grid junction, or a UPS grid junction, includes the identification of the Grid Zone Designation and is written in MGRS terms as:


UTM GRID ZONE DESIGNATION:  22W

UPS GRID ZONE DESIGNATION:  A  

8-3.3 Each grid is shown by full lines within its own area only, being represented in the normal manner at 100,000-unit intervals, intersected by ticks at 10,000-unit intervals. All grid lines are printed in blue.

8-3.4 Grid values appear on all four sides of the sheet (outside the neatline) labeling each grid line. They may also label only the first grid line in each direction from each corner of the sheet. The composition of the number is similar to that described in paragraph 8-2.2, except that full grid values label the first grid line in each direction from each corner of the sheet.

8-3.5 Where appropriate for the grid, identification of 100,000-unit squares and larger unit squares appear on the face of the map, centered within the appropriate squares, as described in paragraph 8-2.3.

8-3.6 Notes identifying each grid appear in the lower margin of the sheet. The note is modeled after the following:


BLUE LINES AT 100,000 METER INTERVALS AND BLUE   
TICKS AT 10,000 METER INTERVALS INDICATE THE     
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE         
DESIGNATIONS 22K AND 23K, INTERNATIONAL ELLIPSOID

BLUE LINES AT 100,000 METER INTERVALS AND BLUE   
TICKS AT 10,000 METER INTERVALS INDICATE THE     
NORD MAROC GRID, CLARKE 1880 ELLIPSOID           

8-3.7 In those cases where a sheet includes an ellipsoid junction, the grids for the two ellipsoids are treated in the same manner as that specified in paragraph 8-3.2. The ellipsoids are identified on each side of the junction line. Where an ellipsoid junction line is coincident with a neatline, both the junction line and the identifying labels are omitted. The grid note in the lower margin of the sheet identifies each ellipsoid which appears on that sheet. It is modeled after the following:


BLUE LINES AT 100,000 METER INTERVALS AND BLUE   
TICKS AT 10,000 METER INTERVALS INDICATE THE     
UNIVERSAL TRANSVERSE MERCATOR GRID, ZONE         
DESIGNATIONS 33T, INTERNATIONAL ELLIPSOID, AND   
ZONE DESIGNATION 33T, WGS ELLIPSOID              

8-3.8 In certain cases, a sheet bearing the UTM grid may straddle a parallel which marks the division between different grid zone designations. A continuous line in black or blue indicates the dividing parallel. The proper grid zone designations, printed in blue appear on each side of the line.

8-3.9 Figures 35 and 36 illustrate principles described for sheets with more than one major grid.


8.4 OVERLAPPING, EXTENDED, AND SECONDARY GRIDS.

Overlapping, extended, or secondary (obsolete) grids are not shown on the 1:1,000,000 scale map.


8-5 GRID AND MAGNETIC DECLINATIONS.

Grid and magnetic declination data are not shown on 1:1,000,000 scale maps.


8-6 THE GRID REFERENCE BOX.

8-6.1 A grid reference box may be shown in the margin of the sheet. The box contains explicit step-by-step instructions for composing a grid reference. See figure 37 for a typical grid reference box.

8-6.2 The grid system(s) in use on the map dictates the referencing instructions contained in the grid reference box.

8-6.3 When more than one major grid appears on a sheet and the method for giving a reference is the same for all the grids, a common reference box is used.

8-6.4 When more than one, major grid appears on a sheet and the method for giving a reference varies with the grids, the treatment of the grid reference boxes is as follows:

8-6.4.1 A grid reference box is shown in the margin for each grid, except those falling completely in open water area. Over each box appears a note limiting the use of the box to the grid or grids concerned.

8-6.4.1.1 When each box describes the method of referencing for one grid only, the note is modeled after the following:


USE THIS BOX FOR GIVING REFERENCES ON THE
UNIVERSAL TRANSVERSE MERCATOR GRID       

USE THIS BOX FOR GIVING REFERENCES ON THE
MADAGASCAR GRID                          

Figure 35. Two Major Grids(in this case, Zones of the UTM) Separated by a Grid Junction, as Shown on a Map at 1:1,000,000 Scale.

Figure 36. Three Major Nonstandard Grids as Shown on a Map at 1:1,000,000 Scale.

8-6-4.1.2 When the same system of referencing is used for two grids occurring on the same sheet with a third grid using a different reference system, the note for the common reference box is modeled after the following:


USE THIS BOX FOR GIVING REFERENCES ON THE
SUD ALGERIE AND SUD TUNISIE GRIDS        

Figure 37. Grid Reference Box for 1:1,000,000 Scale Map

8-6.4.2 When all reference boxes cannot be accommodated in the margin, the excess is shown in expanses of open water on the face of the map. When this is not practicable, a note which refers the user to an adjacent sheet is added to a reference box in the margin. This note is positioned below the note described in paragraph 8-6.4.1.2 above. The notes are modeled after the following:


USE THIS BOX FOR GIVING REFERENCES ON THE
UNIVERSAL TRANSVERSE MERCATOR GRID       

SEE SHEET 1 FOR GIVING REFERENCES ON     
THE NORD MAROC GRID                      

USE THIS BOX FOR GIVING REFERENCES ON THE
UNIVERSAL TRANSVERSE MERCATOR GRID       

SEE SHEET 2 FOR GIVING REFERENCES ON     
THE SUD ALGERIE AND SUD TUNISIE GRIDS   

 


Point of Contact: Geospatial Science Division
phone (314) 263-4486, DSN 693-4486
gandg@nga.mil

Document last modified September 15, 2014

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