Datums, Ellipsoids, Grids, and Grid Reference Systems
TM 8358.1 Front matter through section 1.6
Abstract: This manual describes the basic principles of the Military Grid Reference System and the non-standard reference systems. It describes the method for determining references on maps and charts at scales of 1:1,000,000 and larger. It contains identifications for the grid zone designations and for the 100,000 meter squares of the Universal Transverse Mercator Grid and the Universal Polar Steriographic Grid. It also contains the specifications and grid identifications for the various non-standard grids. It provides diagrams and textual information for delineating geodetic datums and ellipsoids.
Subject Terms: Position location, military grid, geodetic datum, coordinate reference system, ellipsoid, spheroid, graticule, chart, projection.
DEFENSE MAPPING AGENCY
To enhance national security and support the Office of the Secretary of Defense, the Joint Chiefs of Staff, Unified and Specified Commands, Military Departments, and other users, by producing and distributing timely and tailored mapping, charting, and geodetic products, services, and training, and advising on such matters. To provide nautical charts and marine navigational data to worldwide merchant marine and private vessel operators. To maintain liaison with civil agencies and other national and international scientific and other mapping, charting, and geodetic activities.
DEFENSE MAPPING AGENCY
8613 LEE HIGHWAY
FAIRFAX, VIRGINIA 22031-2137
20 SEP 1990
DEFENSE MAPPING AGENCY TECHNICAL MANUAL 8358.1
DATUMS, ELLIPSOIDS, GRIDS, AND
GRID REFERENCE SYSTEMS
- This manual states current authoritative guidance for the use and portrayal of grids and grid reference systems information as applicable to maps and charts compiled for the United States Department of Defense (DoD).
- This publication contains no copyrighted material and has been approved for public release. Distribution is unlimited. DoD users may order copies from the Defense Mapping Agency Combat Support Center, ATTN: PMSR, Washington, D.C. 20315-0020. All other requests should be directed to the National Technical Information Center, Cameron Station, Alexandria, VA 22314-6145.STANLEY O. SMITH Brigadier General, USAF Chief of Staff
DMA TM 8358.1 CONTENTS
LIST OF FIGURES
LIST OF TABLES
- CHAPTER 1 GENERAL
- 1-1 - Authority
- 1-2 - References
- 1-3 - Purpose
- 1-4 - Scope
- 1-5 - Utilization
- 1-6 - Definitions
- 1-7 - Reference Systems
- 1-8 - Standard and Nonstandard Grids
- 1-9 - Multiple Grids
- 1-10 - Overlapping Grids
- 1-11 - Extended Grids
- 1-12 - Grid and Datum Related Marginal Notes
- 1-13 - Supercession
- CHAPTER 2 DATUMS, ELLIPSOIDS, PROJECTIONS AND MILITARY GRIDS
- 2-1 - General
- 2-2 - Horizontal Datums
- 2-3 - Transforming Coordinates from one Horizontal Datum to Another Horizontal Datum
- 2-4 - Ellipsoids
- 2-5 - Projections
- 2-6 - Military Grids
- 2-7 - Transforming Coordinates from one Grid System to Another Grid System
- CHAPTER 3 THE U. S. MILITARY GRID REFERENCE SYSTEM (MGRS)
- 3-1 - General Description
- 3-2 - The Grid Zone Designation
- 3-3 - 100,000-Meter Square Identification
- 3-4 - The Military Grid Reference
- 3-5 - MGRS Application
- CHAPTER 4 THE NONSTANDARD GRID SYSTEMS IN CURRENT USE PAGE
- 4-1 - Nonstandard Grids on Maps and Charts
- 4-2 - Diagrams of Nonstandard Grids
- CHAPTER 5 GEOGRAPHIC COORDINATE REFERENCES
- 5-1 - Use
- 5-2 - The Geographic Reference
- 5-3 - Geographic Coordinates on Maps and Charts
- 5-4 - The World Geographic Reference System
- CHAPTER 6 PORTRAYAL OF GRIDS ON MAPS AT 1:100,000 SCALE AND LARGER
- 6-1 - General
- 6-2 - The Major Grid
- 6-3 - Multiple Major Grids
- 6-4 - Overlapping Grids
- 6-5 - Secondary Grids
- 6-6 - The Declination Diagram (One Grid)
- 6-7 - The Declination Diagram (More Than One Grid)
- 6-8 - The Grid Reference Box
- CHAPTER 7 PORTRAYAL OF GRIDS ON MAPS AT 1:250,000 AND 1:500,000 SCALE
- 7-1 - General
- 7-2 - The Major Grid
- 7-3 - Multiple Major Grids
- 7-4 - Overlapping and Extended Grids
- 7-5 - Secondary Grids
- 7-6 - Grid Declination
- 7-7 - Magnetic Dechnotion
- 7-8 - The Grid Reference Box
- CHAPTER 8 PORTRAYAL OF GRIDS ON MAPS AT 1:1,000,000 SCALE
- 8-1 - General
- 8-2 - The Major Grid
- 8-3 - Multiple Major Grids
- 8-4 - Overlapping, Extended, and Secondary Grids
- 8-5 - Grid and Magnetic Declinations
- 8-6 - The Grid Reference Box
- CHAPTER 9 GRIDS ON NAUTICAL CHARTS AT 1:75,000 SCALE AND LARGER
- 9-1 - General
- 9-2 - The Major Grid on Combat Charts and Amphibious Assault Charts
- 9-3 - The Major Grid on Mine Warfare Charts
- 9-4 - The Major Grid on'Harbor, Approach, and Coastal Charts
- 9-5 - Multiple Major Grids on Combat Charts and Amphibious Assault Charts
- 9-6 - Multiple Major Grids on Harbor, Approach, and Coastal Charts
- 9-7 - Overlapping Grids on Combat Charts, Amphibious Assault Charts, and Mine Warfare Charts
- 9-8 - Overlapping Grids on Harbor, Approach, and Coastal Charts
- 9-9 - Secondary Grids
- 9-10 - The Declination Note
- 9-11 - The Grid Reference Box
- 9-12 - World Geodetic System (WGS) Datum Note
- CHAPTER 10 GRIDS ON NAUTICAL CHARTS AT SCALES SMALLER THAN 175,000
- 10-1 - General
- 10-2 - The Major Grid
- 10-3 - Multiple Grids
- 10-4 - Secondary Grids
- 10-5 - The Grid Reference Box (or Notes)
- 10-6 - World Geodetic System (WGS) Datum Note
- CHAPTER 11 GRIDS ON AERONAUTICAL CHARTS AT 1-500,000 SCALE AND LARGER
- 11-1 - General
- 11-2 - The Major Grid
- 11-3 - Grid Declination
- 11-4 - Magnetic Declination
- 11-5 - The Grid Reference Box
- A - Table of Mil Equivalents
- *B - 100,000-Meter Square Identifications of the Military Grid Reference System (Graphics), Figures B-1 through B-4
- *C - Guide To Geodetic Status Of Large Scale Mapping
- *D -Index to Preferred Grids, Datums and Ellipsoids Specified for New Mapping
* Requires periodic update and revision.
LIST OF FIGURES
1 Defining Parameters of Ellipsoids
2 Mercator Projection
3 Transverse Mercator Projection
4 Secant Condition of Transverse Mercator Projection; Typical 6-degree Projection Zone
5 Polar Stereographic Projection
6 Lambert Conformal Conic Projection
7 Grid Zone Designations of the Military Grid Reference System
8 Basic Plan of the 100,000-meter Square Identifications of the U.S. Military Grid Reference System, Between 84'N. and 80's.
9 Method of Reading a U.S. Military Grid Reference from a 1:250,000 Scale Map
10 Method of Reading a U.S. Military Grid Reference from a Large Scale Map
11 Normal Lettering Plan of the 500,000 - 100,000-unit squares of the British Grid System
12 World Geographic Reference (GEOREF) System
13 The Major Grid as Shown a 1:50,000 Scale Map
14 The Major Grid as Shown on a 1:100,000 Scale Map
15 Two Major Grids (in this case, Zones of the UTM) Separated
16 Three Major Nonstandard Grids as Shown on a Large Scale Map
17 Major and Overlapping Grids as Shown on a Large Scale
18 Overlapping Grid in Combination with Two Major Grids Separated by a Grid Junction as Shown on a Large Scale Map
19 Major and Secondary (Obsolete) Grids as Shown on a Large Scale Map
20 The Declination Diagram and Accompanying Notes with True North Appearing as the Center Prong
21 The Declination Diagram and Accompanying Notes with True North Appearing as an Outside Prong
22 The Declination Data when a Sheet Contains an Overlapping rid and/or More Than One Major Grid
23 Grid Reference Boxes Most Commonly Used on Maps at Coles of 1:100,000 and Larger
24 Methods of Showing Grid Zone Designations and 100,000- meter Squares of the UTM in the Grid Reference Boxes of Large Scale Maps
25 Methods of Showing 100,000-unit, and Larger, Square Identifications of Nonstandard Grids in the Grid Reference Boxes of Large Scale Maps
26 Treatment for the Major Grid in UTM Areas as Shown on a 1:250,000 Map
27 Treatment for the Major Grid in UTM Areas as Shown on Maps Smaller than 1:250,000 Scale and Larger than 1:1,000,000
28 Two Major UTM Grid Zones Separated by a Grid Junction as Shown on a 1:250,000 Scale Map
29 Three Major Nonstandard Grids Separated by Grid Junctions
30 Two Major Grids (UTM) Separated by an Ellipsoid Junction as Shown on a 1:250,000 Scale Map
31 Treatment when Grid Falls within More than One UTM Grid Zone Designation Area as Shown on a 1:250,000 Scale Map
32 Major and Secondary (Obsolete) Grids as Shown on a 1:250,000 Scale Map
33 Grid Reference Boxes Most Commonly Used on Maps at 1:250,000 and 1:500,000 Scale
34 Treatment for the Major Grid in UTM Areas as Shown on Maps at 1:1,000,000 Scale
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
36 Three Major Nonstandard Grids as Shown on a Map at 1:1,000,000 Scale
37 Grid Reference Box for 1:1,000,000 Scale Map
38 The Major Grid as Shown on Combat, Amphibious Assault Charts
39 Two Major Grids (in this case, Zones of the UTM) Separated by a Grid Junction as Shown on Combat, Amphibious Assault Charts
40 Treatment for the Major Grid on Mine Warfare Charts at 1:75,000 Scale and Larger
41 Treatment for the Major Grid on Harbor and Approach Charts at 1:75,000 Scale and Larger
42 Treatment for the Multiple Major Grids on Harbor and Approach Charts at 1:75,000 scale and Larger
43 Grid Reference Boxes Commonly Used on Nautical Charts at Scales of 1:75,000 and Larger
44 Treatment for the Major Grid on Nautical Charts at Scales Smaller than 1:75,000
45 Treatment for Multiple Grids on Nautical Charts at Scales Smaller than 1:75,000
46 Treatment for Major and Secondary Grids on Nautical Charts at Scales Smaller than 1:75,000
47 Grid Reference Box Commonly Used on Aeronautical Charts at 1:500,000 Scale and Larger
LIST OF TABLES
1 Geodetic Datums Used in Map Production
2 Molodenskiy Transformation Constants to Convert from Local Datum to WGS 84
3 Characteristics of Projections
4 Grid Unit Intervals for Various Scale Topographic Maps
5 Dimensions of Grid Zone Designation Areas
6 Specifications for Secondary Grids
7 Corner Labeling on Topographic Maps
8 The Equivalents of 40 Kilometers when Measured Along a Given Parallel of Latitude Expressed in Degrees, Minutes, and Seconds of Longitude
9 Maximum Acceptable Deviation of the Constructed Grid from the True Grid
This document is issued under the authority delegated by DoD Directive 5105.40, subject: Defense Mapping Agency (DMA), 12 December 1988.
1-2.1 The DMA TM 83581 series replaces the DA TM 5-241 series of manuals.
1-2.2 JCS-MOP 88, Position Reference Procedures, 8 May 1981.
1-2.3 STANAG 2211, subject: Geodetic Datums, Ellipsoids, Grids, and Grid References.
1-2.4 STANAG 3676, subject: Marginal Information on Land Maps and Aeronautical Charts.
1-2.5 QSTAG 544, subject: Geodetic Datums, Spheroids, Grids, and Grid References.
1-2.6 IHO Circular Letter 9, International Horizontal Datum for Chart Reference, 15 March 1983.
1-2.7 IHO Circular Letter 28, Transformation Notes, WGS-84, 15 July 1988.
1-2.8 IHO Circular Letter 46, International Horizontal Datum for Chart Reference, 16 December 1983.
1-2.9 IHO Circular Letter 18, Indication on Charts of Relationship of Horizontal Datum to Worldwide and Other Datums, 17 May 1984.
1-2.10 IHO Circular Letter 46, Indication on Charts of Relationship of Horizontal Datum to Worldwide and Other Datums, 14 December 1984.
1-2.11 DMA TM 83581.2 The Universal Grids: Universal Transverse Mercator (UTM) and Universal Polar Stereographic (UPS).
1-2.12 DMA TR 8350.2 (and supplements) Department of Defense World Geodetic System 1984.
1-3.1 This manual provides guidance to DoD Mapping, Charting and Geodesy (MC&G) production elements, product users, and system developers on the application of datums, ellipsoids, grids, and grid reference systems within the DoD.
1-3.2 It describes the standard methods for selecting and portraying grids or maps and charts at scales of 1:1,000,000 and larger. Descriptions are based on the following categories.
1-3.2.1 Topographic Maps.
1-3.2.2 Hydrographic Charts.
1-3.2.3 Aeronautical Charts.
1-4.1 This manual specifies the use of geodetic datums, ellipsoids, grids and grid reference systems used in the production of maps and charts for the DoD.
The Universal Transverse Mercator an d Universal Polar Stereographic grids, the Military Grid Reference System, and nonstandard grid reference systems are described.
1-4.2 Detailed instructions and formats for grid depictions and labeling, grid margin data, declination data, etc. are contained in the DMA product specifications for approved topographic, hydrographic, and' aeronautical products.
1-5.1 TM 83581.1 is to be used by DoD MC&G production elements, product users, and DoD system developers in the application of datums, ellipsoids, grids, and grid reference systems.
1-5.2 Users are cautioned that the information contained herein applies to current and future MC&G production, and does not necessarily apply to products that are currently available through the DoD supply system.
1-6.1 Major Grid. The primary grid or grids on a map or chart.
1-6.2 Military Grid Reference System (MGRS). The alphanumeric position reporting system used by U.S. military. A full description is provided in Chapter 3.
1-6.3 Nonstandard Grids. Grids other than UTM and UPS, such as Ceylon Belt, India Zone IIA, West Malaysian RSO (Metric) Grid, etc.
1-6.4 Operational Grid. A grid in current operational use. Generally this would be the preferred grid but could be a previously prescribed grid.
1-6.5 Overlapping Grid. A major grid from a neighboring area primarily intended to facilitate military surveying anti fire-control.
1-6.6 Preferred Grid. The grid designated by the DoD for production of new maps, charts, and digital geographic data; and shown on the "Index to Preferred Grids, Datums, and Ellipsoids Specified for New Mapping" (Appendix D).
1-6.7 Prescribed Grid. The grid that is locally prescribed, by the country of origin or military commander.
1-6.8 Primary Grid. The major, or principal, grid on a map or chart.
1-6.9 Secondary Grid. Any grid, other than the primary grid, required for combined operations application. Tick marks along the neat lines are the preferred method of portrayal. Such grids should remain on the maps or charts so long as the secondary grid remains in use.
1-6.10 Standard Grids. The Universal Transverse Mercator (UTM) grid and the Universal Polar Stereographic (UPS) grid.
1-6.11 World Geographic Reference System (GEOREF). A worldwide position reference system that may be applied to any map or chart graduated in latitude and longitude regardless of projection. It provides a method of expressing positions in a form suitable for reporting and plotting. The primary use is for interservice and interallied reporting of aircraft and air target positions.
1-6.12 Other Key Terms.
1-6.12.1 Bleeding Edge. That edge of a map or chart on which cartographic detail is extended beyond the neatline to the edge of the sheet.
1-6.12.2 Coordinate Reference Notation Grid coordinates are given in terms of linear in meters. Geographic coordinates are given in terms of angular measurement, usually in degrees, minutes, and seconds but occasionally in grads.
1-6-12.3 Datum. As used in this manual, datum refers to the geodetic or horizontal datum. The classical datum is defined by a minimum of five elements giving the position of the origin (two elements), the orientation of the network (one element), and the parameters of a reference ellipsoid (two elements). More recent definitions express the position and orientation as functions of the deviations in the meridian and in the prime vertical, the geoid-ellipsoid separation, and the parameters of a reference ellipsoid. The World Geodetic System is a geocentric system that provides a basic reference frame and geometric figure for the earth, models the earth gravimetrically, and provides the means for relating positions on various datums to an earth-centered, earth fixed coordinate system.
1-6.12.4 Easting. Eastward (that is left to right) reading of grid values on a map.
1-6.12.5 Ellipsoid. An ellipsoid is a mathematical figure generated by the revolution of of an ellipse about one of its axes. The ellipsoid that approximates the geoid is an ellipse rotated about its minor axis, or an oblate spheroid.
1-6.12.6 False Easting. A value assigned to the origin of eastings, in a grid coordinate system, to avoid the convenience of using negative coordinates.
1-6.12.7 False Northing. A value assigned to the origin of northings, in a grid coordinate system, to avoid the inconvenience of using negative coordinates.
1-6.12.8 Geoid. The equipotential surface in the gravity field of the Earth which approximates the undisturbed mean sea level extended continuously through the continents. The direction of gravity is perpendicular to the geoid at every point. The geoid is the surface of reference for astronomic observations and for geodetic leveling.
1-6.12.9 Graticule. A network of lines representing parallels of latitude and meridians of longitude forming a map projection.
1-6.12.10 Grid. Two sets of parallel lines intersecting at right angles and forming squares; a rectangular Cartesian coordinate system that is superimposed on maps, charts, and other similar representations of the earth's surface in an accurate and consistent manner to permit identification of ground locations with respect to other locations and the computation of direction and distance to other points.
1-6.12.11 Isogonic Line. A line drawn on a map or chart joining points of equal magnetic declination for a given time. The line connecting points of zero declination is the agonic line. Lines connecting points of equal annual change are isopors. The Magnetic Variation chart for the current 5-year epoch is available from the DMACSC.
1-6.12.12 Loxodrome. A line on the surface of the Earth cutting all meridians at the same angle, a rhumb line.
1-6.12.13 Map Projection. An orderly system of lines on a plane representing a corresponding system of imaginary lines on an adopted terrestrial datum surface. A map projection may be derived by geometrical construction or by mathematical analysis.
1-6.12.14 Neatline. The lines that bound the body of a map, usually parallels and meridians (but may be conventional or arbitrary grid lines); also called sheet lines.
1-6.12.15 Northing. Northward (that is from bottom to top) reading of grid values on a map.
1-6.12.16 Spheroid. A mathematical figure closely approaching the geoid in form and size. Ellipsoid will be used in this manual.
Document last modified September 15, 2014