United States National Grid
The United States National Grid (USNG) is a multi-purpose location system of grid references used in the United States. It provides a nationally consistent "language of location", optimized for local applications, in a compact, user friendly format. It is similar in design to the national grid reference systems used in other countries. The USNG was adopted as a national standard by the Federal Geographic Data Committee (FGDC) of the US Government in 2001.
- 1 Overview
- 2 Description: How the USNG works
- 3 History
- 4 Advantages over latitude/longitude
- 5 Limitations and tradeoffs
- 6 Adoption and current applications
- 7 Future direction and initiatives
- 8 See also
- 9 References
- 10 Further reading
- 11 External links
While latitude and longitude are well suited to describing locations over large areas of the Earth's surface, most practical land navigation situations occur within much smaller, local areas. As such, they are often better served by a local Cartesian coordinate system, in which the coordinates represent actual distance units on the ground, using the same units of measurement from two perpendicular coordinate axes. This can improve human comprehension by providing reference of scale, as well as making actual distance computations more efficient.
Paper maps often are published with overlaid rectangular (as opposed to latitude/longitude) grids to provide a reference to identify locations. However, these grids, if non-standard or proprietary (such as so-called "bingo" grids with references such as "B-4"), are typically not interoperable with each other, nor can they usually be used with GPS.
The goal of the USNG is to provide a uniform, nationally-consistent rectangular grid system that is interoperable across maps at different scales, as well as with GPS and other location based systems. It is intended to provide a frame of reference for describing and communicating locations that is easier to use than latitude/longitude for many practical applications, works across jurisdictional boundaries, and is simple to learn, teach, and use. It is also designed to be both flexible and scalable so that location references are as compact and concise as possible.
The USNG is intended to supplement—not to replace—other location systems such as street addresses. It can be applied to printed maps and to computer mapping and other (GIS) applications. It has found increasing acceptance especially in emergency management, search and rescue, and other public safety applications; yet, its utility is by no means limited to those fields.
Description: How the USNG works
The USNG is an alpha-numeric reference system that overlays the UTM coordinate system. A number of brief tutorial references explain the system in detail, with examples. . Briefly, an example of a full USNG spatial address (grid reference) is:
18S UJ 23371 06519
This full form (15 characters) uniquely identifies a single one-meter grid square out of the entire surface of the earth. It consists of three parts (each of which follows a "read-right-then-up" paradigm familiar with other "X,Y" coordinates):
- Grid Zone Designation (GZD); for a world-wide unique address. This consists of up to 2 digits (6-degree longitude UTM zone) for West to East, followed by a letter (8-degree latitude band) from South to North; in this example, "18S".
- 100,000-meter (100 km) Square Identification; for regional areas. This consists of two letters, the first West to East, the second South to North; in this example, "UJ".
- Grid Coordinates; for local areas. This part consists of an even number of digits, in this example, 23371 06519, and specifies a location within the 100 km grid square, relative to its lower-left corner. Split in half, the first part (here 23371), called the "easting", gives the displacement east of the left edge of the square; the second part (here 06519), called the "northing"), gives a distance north of the bottom edge of the containing square.
- Users determine the required precision, so a grid reference is typically truncated to fewer than the full 10 digits when less precision is required. These values represent a point position (southwest corner) for an area of refinement:
- Ten digits..... 23371 06519 ..Locating a point within a 1 m square
- Eight digits..... 2337 0651 …Locating a point within a 10 m square
- Six digits...…… 233 065 …..Locating a point within a 100 m square
- Four digits...…... 23 06 …….Locating a point within a 1000 m (1 km) square
- Two digits...…….. 2 0 ……...Locating a point within a 10000 m (10 km) square
- Note that when going from a higher- to a lower-precision grid reference, it is important to truncate rather than round when removing the unneeded digits. Because one is always measuring from the lower-left corner of the 100 km square, this ensures that a lower-precision grid reference is a square that contains all of the higher-precision references contained within it.
- Users determine the required precision, so a grid reference is typically truncated to fewer than the full 10 digits when less precision is required. These values represent a point position (southwest corner) for an area of refinement:
In addition to truncating references (on the right) when less precision is required, another powerful feature of USNG is the ability to omit (on the left) the Grid Zone Designation, and possibly even the 100 km Square Identification, when one or both of these are unambiguously understood; that is, when operating within a known regional or local area. For example:
- Full USNG: 18S UJ 23371 06519 (world-wide unique reference to 1 meter precision)
- Without Grid Zone Designation: UJ 2337 0651 (when regional area is understood; here to 10 meter precision)
- Without 100 km Square Identification: 233 065 (when local area is understood; here to 100 meter precision)
Thus in practical usage, USNG references are typically very succinct and compact, making them convenient (and less error prone) for communication.
Rectangular, distance-based (Cartesian) coordinate systems have long been recognized for their practical utility for land measurement and geolocation over local areas. In the United States, the Public Land Survey System (PLSS), created in 1785 in order to survey land newly ceded to the nation, introduced a rectangular coordinate system to improve on the earlier metes-and-bounds survey basis used earlier in the original colonies. In the first half of the 20th Century, State Plane Coordinate Systems (SPCS) brought the simplicity and convenience of Cartesian coordinates to state-level areas, providing high accuracy (low distortion) survey-grade coordinates for use primarily by state and local governments. (Both of these planar systems remain in use today for specialized purposes.)
Internationally, during the period between World Wars I and II, several European nations mapped their territory with national-scale grid systems optimized for the geography of each country, such as the Ordnance Survey National Grid (British National Grid). Near the end of World War II, the Universal Transverse Mercator (UTM) coordinate system extended this grid concept around the globe, dividing it into 60 zones of 6 degrees longitude each. Circa 1949, the US further refined UTM for ease of use (and combined it with the Universal Polar Stereographic system covering polar areas) to create the Military Grid Reference System (MGRS), which remains the geocoordinate standard used across the militaries of NATO counties.
In the 1990s, a US grass-roots citizen effort led to the Public X-Y Mapping Project, a not-for-profit organization created specifically to promote the acceptance of a national grid for the United States. The Public XY Mapping Project developed the idea, conducting informal tests and surveys to determine which coordinate reference system best met the requirements of national consistency and ease of human use. Based on its findings, a standard based on the MGRS was adopted and brought to the Federal Geographic Data Committee (FGDC) in 1998. After an iterative review process and public comment period, the USNG was adopted by the FGDC as standard FGDC-STD-011-2001 in December 2001.
Since then, the USNG has seen gradual but steadily increasing adoption both in formal standards and in practical use and applications, in public safety and in other fields.
Advantages over latitude/longitude
Users encountering the USNG (or similar grid reference systems) sometimes question why they are used instead of latitude and longitude coordinates, with which they may be more familiar. Proponents note that, in contrast to latitude and longitude coordinates, the USNG provides:
- Coordinate units that represent actual distances on the ground
- Equal distance units in both east-west and north-south directions
- An intuitive sense of scale and distance, across a local area
- Simpler distance calculation (by Pythagorean Theorem, rather than spherical trigonometry)
- A single unambiguous representation instead of the three (3) formats of latitude and longitude, each in widespread use, and each having punctuation sub-variants:
- degrees-minutes-seconds (DMS): N 38°53'23.3", W 077°02'11.6"
- degrees-minutes-decimal minutes (DMM or DDM): 38°53.388' N, 077°02.193' W
- decimal degrees (DDD or DD): 38.88980°, -077.03654°
- References comprising only alphanumeric characters (letters and positive numbers). (Spaces have no significance but are allowed for readability.)
- No negative numbers, hemisphere indicators (+, -, N, S, E, W), decimal points (.), or special symbols (°, ′, ″, :).
- A familiar "read right then up" convention of XY Cartesian coordinates.
- An explicit convention for shortening references (at two levels) when the local or regional area is already unambiguously known.
- A reference to a definite grid square with variable, explicit precision (size), rather than to a point with (usually) unspecified precision implicit in number of decimal places.
All of the above also lead to USNG references being typically very succinct and compact, with flexibility to convey precise location information in a short sequence of characters that is easily relayed in writing or by voice.
Limitations and tradeoffs
As with any projection that seeks to represent the curved Earth as a flat surface, distortions and tradeoffs will inevitably occur. The USNG attempts to balance and minimize these, consistent with making the grid as useful as possible for its intended purpose of efficiently communicating practical locations. Since the UTM (the basis for USNG) is not a single projection, but rather a set of 6-degree longitudinal zones, there will necessarily be a local discontinuity along each of the 'seam' meridians between zones. However, every point continues to have a well-defined, unique geoaddress, and there are established conventions to minimize confusion near zone intersections. [cite] The six-degree zone width of UTM strikes a balance between the frequency of these discontinuities versus distortion of scale, which would increase unacceptably if the zones were made wider. (UTM further uses a 0.9996 scale factor at the central meridian, growing to 1.0000 at two meridians offset from the center, and increasing toward the zone boundaries, so as to minimize the overall effect of scale distortion across the zone breadth.) The USNG is not intended for surveying, for which a higher-precision (lower-distortion) coordinate system such as SPCS would be more appropriate. Also, since USNG north-south grid lines are (by design) a fixed distance from the zone central meridian, only the central meridian itself will be aligned with "true north". Other grid lines establish a local "grid north", which will differ from true north by a small amount. The amount of this deviation, which is indicated on USGS topographic maps, is typically much less than the magnetic declination (between true north and magnetic north), and is small enough that it can be disregarded in most land navigation situations.
Adoption and current applications
Since its adoption as a national standard in 2001, the USNG has itself been incorporated into standards and operating procedures of other organizations:
- In 2011, the US Government's National Search and Rescue Committee (NSARC) released Version 1.0 of the Land Search and Rescue Addendum to the National Search and Rescue Supplement to the International Aeronautical and Maritime Search and Rescue Manual. This document specifies the US National Grid as the primary standard coordinate reference system to be used for all land-based search and rescue (SAR) activities in the US.
- In 2015, the Federal Emergency Management Agency (FEMA) issued FEMA Directive 092-5, "Use of the United States National Grid (USNG)", whose stated purpose is "...to require use of the USNG as FEMA’s standard geographic reference system across all preparedness, mitigation, response, and recovery activities as well as land-based and land-air operations and to provide instruction for effective implementation." 
- A number of state and local Emergency Management agencies have also adopted the USNG for their operations.
- Other organizations including the National Fire Protection Association (NFPA)  and the Society of Automotive Engineers (SAE)  have incorporated the USNG into specific standards issued by those organizations.
The utility of almost every large or medium scale map (paper or electronic) can be greatly enhanced by having an overlaid coordinate grid. The USNG provides such a grid that is universal, interoperable, non-proprietary, works across all jurisdictions, and can readily be used with GPS receivers and other location service applications.
In addition to providing a convenient means to identify and communicate specific locations (points and areas), an overlaid USNG grid also provides an orientation, and—because it is distance based—a scale of distance that is present across the map.
USGS topographic maps have for decades been published with 1000-meter UTM tick marks in the map collar, and sometimes with full grid lines across the map. Recent editions of these maps (those referenced to the North American datum of 1983, or NAD83) are compatible with USNG, and current editions also contain a standard USNG information box in the collar which identifies the GZD(s) (Grid Zone Designator(s) and the 100 km Grid Square ID(s) covering the area of the particular map. USNG can now be found on various pre-printed and custom-printed maps available for purchase, or generated from various mapping software packages.
A growing number of software applications incorporate or refer to the US National Grid. See the External Links section below for links to some of these, including The National Map (USGS). These applications include conventional mapping applications with overlaid USNG grid and/or coordinate readouts, and several 'you-are-here' mobile applications which give the user's current USNG coordinates.
Search and rescue (SAR)
As noted above under Standards, since 2011 the USNG has been designated by the US Government's National Search and Rescue Committee (NSARC) as the primary coordinate reference system to be used for all land-based search and rescue (SAR) activities in the US. (Latitude and longitude [DMM variant] may be used as the secondary system for land responders; especially when coordinating with air and sea based responders who may use it as their primary system, and USNG as secondary.)
The National Association for Search and Rescue (NASAR) is moving its education and certification testing programming towards USNG. Other organizations such as the National Alliance for Public Safety GIS (NAPSG) also provide USNG SAR training.
Emergency Location Marker (ELM)
Responders are often faced with significant geolocation issues when a responding to an emergency without a street address. This is particularly true in the recreational trail environment:
- 34% of U.S. response calls go to a location without a street address – recreational trails are a leading category, [cite1]
- Trails with location signs typically employ an approach unique to that park or trail system, and
- Locally unique marking systems have no value to responders unless those locations are readily available via dispatch and response systems.
In response to these issues, in 2009, a project funded by the nonprofit SharedGeo and University of Minnesota/Minnesota Department of Transportation Local Operational Research Assistance (OPERA) grant program got underway which had the following objectives [cite2] :
- Develop a standardized Emergency Location Marker (ELM) which can be used anywhere in the nation in a variety of scenarios,
- Align the marking system with established federal and state cartographic and signage standards,
- Ensure the format leverages GPS instead of requiring constant updating of Computer Aided Dispatch systems,
- Use a consistent approach which over time will become instantly recognizable by the public, and
- Involve multiple stakeholders during development to ensure a “Best Practices” outcome.
After three years of field research and vetting by multiple focus groups of trail users, responders, and geospatial experts, a design based on USNG was adopted.
This format, which can be used anywhere in the United States, was originally offered in three sizes to conform to federal, state and local signage standards:
- 6"x9" (non-motorized trails),
- 9"x12" (motorized trails),
- 12"x12" (trail heads and huts).
In the years since introduction, the USNG ELM program now includes vertical ELM versions for breakaway scenarios (e.g. mountain bike trails), ELM information signs, ELM stickers to retrofit trail posts, and corresponding apps such as usngapp.org.
Much of the original impetus behind adoption of USNG as a standard came from the professional Emergency Management community. As summarized in the relevant Federal Emergency Management Agency (FEMA) policy overview:
"Effective preparedness for, response to, and recovery from large-scale and catastrophic incidents affecting multiple jurisdictions requires the use of a uniform point and area reference system. Lessons learned from several large-scale disasters within the past three decades highlight the need for a common, geographic reference system in order to anticipate resource requirements, facilitate decision-making, and accurately deploy resources. While existing data collection and geographic technologies support some decision-making requirements, integration of the USNG into these technologies allows them to deliver fully functional location-enabled decision support. Decision support tools that apply the USNG enable emergency managers to locate positions and identify areas of interest or operations where traditional references (i.e., landmarks or street signs) may be destroyed, damaged, or missing due to the effects of a disaster. Implementing a common location reference for daily and disaster operations ensures familiarity and increases capability to consistently and accurately communicate critical location-enabled information in often austere environments of disaster operations."
The Department of Defense also has recognized the role of the civil USNG standard for the Armed Forces in support of homeland security and homeland defense.
Recreation and other uses
Although much of the attention and application of the USNG has centered on important emergency management, response and other public safety aspects, its utility extends well beyond these fields. [specify/examples]  One such area is Asset Identification and Mapping [separate section?] 
Future direction and initiatives
The USNG has seen steady but gradually increasing adoption and use since the standard was approved in 2001. Formal adoption by other standards bodies has taken place, while practical adoption in actual use has been more uneven in achieving its full potential. In 2018, the USNG Institute (UGNGI) was established "to study and report on USNG implementation efforts taking place across the United States" , as was a USNG Implementation Working Group (USNG IWG) to help assist and coordinate implementation efforts.
Further adoption of USNG for public safety and the Emergency Location Marker (ELM) system may depend in part on greater coordination of USNG adoption at Public Safety Answering Points (PSAPs, or 911 centers), in their procedures and Computer-Aided-Dispatch systems. Currently such implementations, being generally under local control, have been more fragmented than some national adoption initiatives.
Proponents of the USNG envision many other ways in which it could play roles in improving safety, convenience, and quality of life. [specify] 
- Cartesian coordinate system
- Grid reference
- Ordnance Survey National Grid (British National Grid)
- Irish national grid reference system
- Spatial Reference System
- List of National Coordinate Reference Systems
- Universal Transverse Mercator coordinate system (UTM)
- Military Grid Reference System (MGRS)
- Federal Geographic Data Committee (FGDC)
- Public Land Survey System (PLSS)
- State Plane Coordinate System (SPCS)
- Carnes, John (2002). UTM: Using your GPS with the Universal Transverse Mercator Map Coordinate System. MapTools. ISBN 0-9710901-0-6.
- Foster, Roger (December 2008). "Why Do We Have Grids On Maps?" (PDF). Basic Geodesy ; National Geospatial-Intelligence Agency. Retrieved 17 September 2019.
Latitude and longitude are appropriate for referencing a single location in relation to the rest of the earth, bur for referencing numerous locations in relation to each other, within a relatively small area, latitude and longitude becomes very cumbersome.
- National Geospatial-Intelligence Agency. "How to Read US National Grid (USNG) Coordinates" (PDF). NGA.
- MapTools. "A Quick Guide to Using USNG Coordinates".
- Federal Geographic Data Committee. "US National Grid: Read Right Then Up [FGDC USNG Info Sheet 1]" (PDF).
- Federal Geographic Data Committee (2 April 2008). "USNG Coordinates: World-Wide Context [FGDC USNG Info Sheet 2]" (PDF). Retrieved 4 March 2019.
- Federal Geographic Data Committee (2 April 2008). "Reading US National Grid (USNG) Coordinates: Using a Coordinate Scale [FGDC USNG Info Sheet 3]" (PDF). FGDC. Retrieved 4 March 2019.
- Federal Geographic Data Committee. "The US National Grid: A Simple and Powerful Geospatial Tool [FGDC USNG Info Sheet 4]" (PDF). FGDC. Retrieved 2 March 2019.
- National Geospatial-Intelligence Agency. "US National Grid Index Map" (PDF). FGDC. Retrieved 4 March 2019.
- Terry, Tom. "The United States National Grid (Article 1 of 2)" (PDF). Professional Surveyor Magazine, October 2004. Retrieved 2 March 2019.
- Terry, Tom. "Geoaddress: Where Is It? (USNG Article 2 of 2)" (PDF). Professional Surveyor Magazine, November 2004. Retrieved 2 March 2019.
- Federal Geographic Data Committee (December 2001). "United States National Grid Standard (FGDC-STD-011-2001) (1 MB)" (PDF). FGDC.
- Price, Mike. "Introducing the United States National Grid". ESRI - ArcUser Online, July–September 2005. Retrieved 27 May 2019.
- National Geospatial-Intelligence Agency, Office of GEOINT Sciences, Coordinate Systems Analysis (March 2007). "The Universal Grid System [tying together UTM/UPS, MGRS, and USNG]" (PDF). NGA.mil. Retrieved 17 September 2019.CS1 maint: multiple names: authors list (link)
- Cole, Wilford (1977). "Using the UTM Grid System to Record Historic Sites". National Park Service. Retrieved 24 April 2019.
- Flaherty, Mary Pat; Johnson, Jenna (23 August 2009). "Md. Medical Helicopter Faced Problems In Air And On Ground Before Fatal Crash". The Washington Post. Retrieved 4 March 2019.
Baltimore had provided the coordinates as raw numbers, without specifying that they were in...degrees, minutes and seconds: 38 52 17, -76 52 26. ... Prince George's dispatchers and others mapped the coordinates differently, rendering them as decimal degrees...: 38.5217, -76.5226. Viewed that way, the numbers plotted to the coastline in Calvert County, 40 miles southeast of where Trooper 2 last was flying -- and searchers from several agencies tracked over Calvert in one of the night's misguided hunts.
- WOOD-TV8 (Grand Rapids, MI) (5 January 2018). "Software update sends Aero Med pilot to wrong scene" (video)". YouTube. Retrieved 15 April 2019.
It had to do with...the coordinates being in a different format.
- EPC Updates (1 March 2012). "NSARC Designates USNG as the Land SAR Coordinate System". EPC Updates (St. Paul MN). Retrieved 2 March 2019.
- Federal Emergency Management Agency (FEMA) (15 October 2015). ""FEMA Directive 092-5 - Use of the United States National Grid (USNG)"" (PDF). NAPSG. Retrieved 2 March 2019.
- Florida Division of Emergency Management. "US National Grid". floridadisaster.org. Retrieved 19 April 2019.
- USNG Information Center (SharedGeo). "USNG Directives (Operational Directives and Standards)". USNG Information Center. Retrieved 3 March 2019.
- SAE International. "The US National Grid Standard SAE1002". Retrieved 10 March 2019.
- Boyer, Chris (22 August 2017). "NASAR Audits Programs". National Association for Search and Rescue (NASAR). Retrieved 23 April 2019.
NASAR is moving our navigation education and testing towards USNG.
- Martin, Eric; et al. (2008). Introduction to Search and Rescue (2nd ed.). National Association for Search and Rescue (NASAR). p. 70.
- Cooper, Donald; et al. (2005). Fundamentals of Search and Rescue. Sudbury, MA: National Association for Search and Rescue. pp. 146–148. ISBN 0-7637-4807-2 – via Jones and Bartlett Publishers.
- National Alliance for Public Safety GIS (NAPSG). "Applying USNG for Search and Rescue (Virtual Training)". Retrieved 15 April 2019.
- "Cobb County (GA) expands trail marker program (video)". YouTube. Retrieved 2 March 2019.
- Ojeda-Zapata, Julio (5 November 2015). "Minnesota Marker Signs Might Look Funny - Until You're Lost and Need One". Twin Cities Pioneer Press. Retrieved 4 March 2019.
- Lake County (MN) Emergency Management (2013). "US National Grid Trail Markers / Arrowhead Region, MN [brochure]" (PDF). USNG Center. Retrieved 10 March 2019.
- Cook County (MN) (7 June 2016). "US National Grid Emergency Location Markers". YouTube. Retrieved 15 April 2019.
- Casement, Sue. "A Skier Lost in Minnesota's Arrowhead Looks Up and Sees This: Hope". 3M. Retrieved 10 March 2019.
- Adler, Erin (9 April 2016). "Lost in a Dakota County park? Help is on the way, thanks to new signs". Minneapolis Star Tribune. Retrieved 24 April 2019.
- Robbins, Benjamin (2015). "Eagle Scout Service Project: Hawaii Volcanoes National Park". Retrieved 10 March 2019.
- Robbins, Benjamin (2015). "...Installing...Emergency Location Markers (ELMs)...in Hawaii Volcanoes National Park to assist lost visitors". Scout.org. Retrieved 24 April 2019.
- Gregory, Mike (22 March 2008). "Situational Awareness and Common Operating Picture in Emergency Management" (PDF). pp. 54–58. Retrieved 9 April 2019.
- Federal Emergency Management Agency (FEMA). "FEMA USNG Training Video". YouTube. Retrieved 4 March 2019.
- National Alliance for Public Safety GIS (NAPSG). "Use of the US National Grid to Enhance Situational Awareness & Define Operational Areas" (PDF). NAPSG. Retrieved 15 April 2019.
- National Alliance for Public Safety GIS (NAPSG). "USNG and Pre-Scripted MIssions" (PDF). Retrieved 15 April 2019.
- Delta State University (September 2017). "DSU Geospatial Information Technologies Center responds to Hurricane Harvey". Delta State University. Retrieved 4 March 2019.
- Brooks, Talbot (2017). "Grid-Based Risk Modeling: A Standards Approach (OR: Saving the World One Grid Square at a Time)" (PDF). ESRI. Retrieved 16 April 2019 – via Proceedings of the 2017 ESRI National Security and Public Safety Summit.
- Brooks, T. 2006. Keynote Speech - Response to Hurricane Katrina and the beneﬁt of the USNG. New York Geographic Information Systems Annual GIS Conference, Lake Placid, NY.
- Department of Defense (14 May 2015). "Chairman of the Joint Chiefs of Staff Instruction (CJCSI) 3900.01D: Position (Point and Area) Reference Procedures, 14 May 2015" (PDF). jcs.mil. pp. This document provides guidance to the Armed Forces on how to reference positions. Paragraph 4.a.(2) addresses the role of the FGDC’s USNG standard for the Armed Forces in support of homeland security and homeland defense. Retrieved 5 April 2019.
- Studt, Al (Lt.); Scott, Bruce (Capt.). "The USNG: It's Time to Stop Adopting and Start Implementing" (PDF). Florida Fire Service, October 2012. Retrieved 5 March 2019.
- Studt, Al (Lt.) (November 2018). "Easy Geo-Location". The Volunteer Firefighter. Retrieved 10 March 2019.
- Inouye, Robert; Dolf, Jason. "USNG for Iowa's First Responders (presentation)". IowaDOT.gov. Retrieved 19 April 2019.
- Iowa Task Force 1 (IA-TF1). "Using USNG (Module 5 of IA-TF1 Missing Person SAR Video Series)". Iowa Task Force 1: Urban Search and Rescue. Retrieved 27 May 2019.
- Knippel, Randy (April 2018). "US National Grid: Get In The Game [video]". Vimeo. Retrieved 4 March 2019.
- Florida Fire Chief's Association. "Position statement: US National Grid map updates and systems configuration". FFCA. Retrieved 2 March 2019.
- Sperlongano, Jessica (29 April 2006). "Which Way to the National Grid?" (PDF). National Journal. Retrieved 2 March 2019.
- West, Pat (20 July 2004). ""Get on the National Grid"" (PDF). Fire Chief Magazine. Retrieved 2 March 2019.
- Charles, Dan (25 February 2006). ""New Kind of Map Could Help Emergency Response"". NPR.
- DeGironimo, E.T. 2014. What’s in a name? Unique asset identiﬁcation using USNG coordinates. New York Geographic Information Systems Annual GIS Conference, Saratoga Springs, NY.
- Knauss, M.S. 2019. The United States National Grid-Where Asset Mapping and First Responders Meet. New York State Association of Transportation Engineers Annual Conference, Tarrytown, NY.
- USNGI. "USNG Institute". Retrieved 10 March 2019.
- A Quick Guide to Using USNG Coordinates (MapTools)
- How to Read US National Grid (USNG) Coordinates (FGDC/NGA)
- How to Read USNG Spatial Addresses (FGDC)
- A Quick Guide to the USNG (NAPSG via USNG Center)
- United States National Grid Standard (FGDC-STD-011-2001) (FGDC, official standard)
- FEMA Directive 092-5: Use of the United States National Grid (USNG) (FEMA policy directive)
- Implementation Guide to the USNG (NAPSG)
- Emergency Location Marker (ELM) system (USNG Florida on Medium)
- Hikers, Know Your Grid! (USNG Florida on Medium)
- 911 Caller Location Solutions (USNG Florida on Medium)
- Why PSAPs Should Be Using The U.S. National Grid To Find 911 Callers (Kova Corp)
- An Introduction to Standards-Based GIT and the US National Grid
- Instructions for GIS Asset Naming Using the U.S. National Grid (USNG)
- General information sites about the USNG:
- U.S. National Grid Information Center
- USNG home page at the Federal Geographic Data Committee (FGDC)
- USNG resources at the NAPSG Foundation
- USNG resources at ESRI
- USNG Florida
- USNG Iowa
- USNG resources at Florida Division of Emergency Management
- USNG resources at Minnesota Geospatial Information Office
- USNG resources at Dakota County (MN)
- USNG resources at Clinton County (OH)
- Online mapping and coordinate conversion sites:
- USNGapp.org and FindMeSAR.com (mobile applications that give the user's current coordinates, e.g., for relay on calls for help)
- GISsurfer (a general purpose web map with a USNG overlay and more)
- GISsurfer: USNG and MGRS Coordinates (documentation, including "Why are USNG coordinates important?")
- NAPSG Situational Awareness Viewer (select Grid Overlay button in toollbar for USNG)
- The National Map Viewer (USGS; set coordinate display to USNG)
- NOAA/NWS Enhanced Data Display (EDD) (with USNG coordinate display enabled)
- Utility to convert latitude and longitude to USNG (NOAA/NGS)
- Emergency Location Marker (ELM) system brief introductory videos:
- Fire Engineering's USNG Video Series