Press Release: Release of Free Magnetic Declination Diagram Service

January 14, 2021 by Steve Swazee No Comments

For Immediate Release
Contact: Steve Swazee
888-877-7436 •

St. Paul, Minnesota, January 14, 2021 – SharedGeo is pleased to announce it has created an open source solution to a longstanding cartographic problem by creating a free web service to generate a magnetic declination diagram.

In cartography, a declination diagram is used to provide a graphic representation of the variations between true north, grid north, and magnetic north on a map.  True north is the center of the earth’s rotation.  Grid north is the orientation of the map projection coordinate system.  Magnetic north is the point at which the earth’s magnetic field points vertically downward in the northern hemisphere; a compass north needle points to this location.  Magnetic north changes over time due to changes in the magnetic field of the core of the Earth.  A declination helps a map user make adjustments in bearings when using a compass and a map for navigation.

Although many utilities exist for calculating the declination angles, creating a suitable declination diagram manually can be tedious, especially when creating a map series that spans a large area.  This is because the declination diagram will be unique to each map, representing the differences between the three norths at the center of the map at a specific point in time.  However, the SharedGeo web service creates a declination diagram automatically, returning a scalable image that can be inserted into a map layout using mapping software.  This utility uses the NOAA World Magnetic Model (

A properly formatted URL in a web browser returns the declination image as a PNG or SVG file, which can be saved and added to a map layout.  It can also be added as a dynamic image using the URL directly, if the mapping software supports that.  Further, when generating a map series using desktop GIS or automation scripting, the extents of each map can include the URL with the coordinates for the center of the map to dynamically generate the declination diagram for each map as it is created.

The base URL is, but requires several arguments to work, including date, lat, lon, and zone where:

  • Date – a decimal date.  The whole number is the year and digits after the decimal represent the portion of the year corresponding to a specific day.  There are many utilities online to convert dates of various formats to a decimal date.  Minimum required is the year (whole number).  Note that the current magnetic model is valid through 2025.
  • Lat – latitude in decimal degrees of the center of the map
  • Lon – Longitude in decimal degrees of the center of the map (positive = East, negative = West)
  • Zone – UTM zone of the map
  • Of – Output format – PNG or SVG – PNG is the default, if this argument is not specified.


Two additional arguments are supported to adjust the size of the output image; width and height.  Note that scaling a larger image effectively creates higher resolution images and, therefore, finer line widths and text characters when the image is reduced in size.

Although some GIS software has add-on components which will generate a declination diagram at an additional cost, and free websites can be used to calculate the declination angles, SharedGeo provides this free utility to generate a magnetic declination diagram image that can be directly incorporated in a map.  More information can be found here:

About SharedGeo: SharedGeo is a Minnesota 501(c)3 nonprofit dedicated to helping government, nonprofit, education, and corporate entities use mapping technologies and share geographic data for the public good. Past and current collaborative partners include federal, state, tribal, county, municipal, nonprofit, and corporate entities.

SharedGeo Releases the Minnesota Situational Awareness Viewer

August 19, 2020 by central No Comments

As a way to provide the Minnesota public with a “one-stop-shop” for publicly available emergency/disaster planning and response mapped information, SharedGeo has created the Minnesota Situational Awareness Viewer (MNSAV). Extensive research was conducted to ensure the public domain data sources used were the best available as of date of map release in August 2020.

Although initial incident information presented focuses on response to COVID-19, data related to other types of incidents common in Minnesota such as significant flooding and wildfires can be added as they occur in the years ahead.  Similarly, future development plans anticipate directly incorporating many of the individual data resources presently listed in the “Other Situational Awareness Maps and Info” section.

MNSAV was designed and implemented by SharedGeo programmer Nicole Helgeson using a Leaflet mapping framework. It can be accessed directly via the dedicated domain of


Kennesaw Mountain National Battlefield Park Installs SharedGeo Emergency Location Marker System

June 11, 2020 by central No Comments

The growing popularity of SharedGeo’s Emergency Location Marker (ELM) system based on the U.S. National Grid federal coordinate standard was recently highlighted when Kennesaw Mountain National Battlefield Park opted to install ELMs.  The park’s 2,965 acres of historic and recreational space located in suburban Atlanta has made it one of the nation’s busiest national parks.  In recent years, over 2.5 million people have annually visited the park.

Because many trails in the park are unimproved and meander in ways which have confused even experienced response teams, the park decided to follow Cobb County’s lead and leverage the ELM system.  In doing so, a uniform geo-referencing system for response on trails and other locations without street addresses has now been established for both inside the park and in the surrounding north Atlanta metro.

Learn more by watching the YouTube video at this link:

SharedGeo Administrative Director Dr. Nancy Reed Interviewed by Voice of America

April 25, 2020 by central No Comments

Recently, Dr. Nancy Reed, SharedGeo Administrative Director was interviewed by Voice of America about SharedGeo’s U.S. Spread of COVID-19 Maps and Analytics website. Other individuals featured in the piece included academics from Johns Hopkins University, University of Virginia, and California State University – Northridge.  The interview by Alex Gorbachev, International Multimedia Journalist for Voice of America Russian Service, was broadcast on Saturday, April 18 to help millions of citizens in former USSR states understand the significant impact COVID-19 was having in the U.S. and how mapping technologies were being employed during the pandemic.

Voice of America (VOA) is the largest U.S. international broadcaster, providing news and information in more than 40 languages to an estimated weekly audience of more than 280 million people. It is carried on a network of more than 2,500 affiliate stations.

Dr. Reed’s interview (in Russian) is available by clicking this link.

Executive Director Swazee on Iowa Public Television

April 21, 2020 by central No Comments

In a human-interest piece produced by Colleen Krantz of Iowa Public Television for PBS’s nationally syndicated program Market-to-Market, Executive Director Steve Swazee was interviewed about SharedGeo’s efforts to promote use of the U.S. National Grid (USNG) as the “emergency response language of location.”  In a segment entitled Advocates Urge Adoption of Old Grid for Geolocation which aired April 17th, Director Swazee was joined by responders and others in advocating for Emergency Services Sector (ESS) use of the USNG geolocation standard – the civilianized version of the Military Grid Reference System (MGRS) which has been in use by U.S. Armed Forces and NATO for communicating location for more than 70 years.  With 34% of the nation’s emergency response calls being dispatched to locations without a street address, Swazee encouraged adoption of the USNG geolocation standard as the answer for this communication problem. In recent years, USNG use has been formally endorsed by the Department of Homeland Security, Federal Geographic Data Committee, National Search and Rescue Committee, Society of Automotive Engineers and many other response, technical and cartographic organizations.

You can view the story at the following link:

SharedGeo Tracks COVID-19 Spread Across the U.S.

April 14, 2020 by central No Comments

In support of COVID-19 public health awareness efforts, on March 19, 2020, SharedGeo officially launched a web map interface which allows users to visualize the spread of the virus across the U.S. since early March. Unique to the map is a time sequence display of county level data made available by University of Virginia’s Biocomplexity Institute’s COVID-19 Surveillance Dashboard and the Coronavirus COVID-19 Global Cases map by the Center for Systems Science and Engineering (CSSE) at John Hopkins University.

In announcing release of the map, SharedGeo indicated it had two objectives:

1.) To visually demonstrate to U.S. citizens the rapidly expanding nature of the COVID-19
virus so individuals and organizations will take to heart the warnings, precautions, and
preventive measures requested by the Centers for Disease Control and Prevention and
others in the medical and Public Health sectors, and

2.) To start a discussion about the need for better granularity of location reporting when dealing with health crises. Across the spectrum of disasters which can befall a nation,
nothing is more pervasive and debilitating than pandemic. Yet, the critical role which
location intelligence can play in managing these types of situations has been historically
lacking. This remains true despite there being effective ways to provide medically
related location data without violating patient privacy. For an example, see

SharedGeo will update the map daily so long as data is available, and the map’s availability is
deemed worthwhile.

To view the map, go here:

Brian Huberty Joins the SharedGeo Board of Advisors

January 8, 2020 by central No Comments

SharedGeo is extremely pleased to welcome Brian Huberty to the SharedGeo Board of Advisors.

Over the last four decades, Mr. Huberty has applied remote sensing and geospatial assessment technologies for the Minnesota Department of Natural Resources, Department of the Interior – U.S. Fish and Wildlife Service and U.S. Geological Survey, U.S. Department of Agriculture – Forest Service and Natural Resources Conservation Service, and with the Aerial Image Technology corporation. Prior to his retirement from the U.S. Fish and Wildlife Service in September 2019, Mr. Huberty was one of the U.S. government’s most senior environmental remote sensing scientists.

Mr. Huberty has B.S. and M.S. degrees from the University of Minnesota, College of Natural Resources; specializing in geospatial resource inventory systems. He is an American Society for Photogrammetry and Remote Sensing (ASPRS) certified Mapping Scientist – RS130, and previously served as Director of ASPRS’s National Primary Data Acquisition Division, and President of its Western Great Lakes Region. He also has served as Chair of the International Society for Photogrammetry and Remote Sensing’s Technical Commission I, Working Group VI – Airborne Optical Sensor Systems.

NASA’s Kennedy Space Center Completes Install of SharedGeo’s Emergency Location Marker System

August 1, 2019 by central No Comments

During deliberations in 2018, NASA’s Office of the Chief Technologist, Innovation Without Boundaries panel selected SharedGeo’s Emergency Location Marker (ELM) system for install on the nation’s space center.  In an effort led by Al Studt who serves as the Lead Fire Suppression & Protective Systems Engineer at Kennedy Space Center and as a Lieutenant with the Cape Canaveral Fire Department, SharedGeo worked closely with Kennedy Space Center personnel to develop and deliver ELM’s and informational signs which support the unique needs of this iconic American location visited by more than one million individuals each year.  In addition to placement on Kennedy Space Center proper, ELM’s were also installed on the adjoining U.S. Fish & Wildlife Service’s Merritt Island Refuge and the Canaveral National Seashore.  You can read more about the project here.

SharedGeo Partners to Bring OSGeo Community Sprint to Minneapolis

May 20, 2019 by central No Comments

In partnership with the Open Source Geospatial Foundation (OSGeo) and University of Minnesota, Twin Cities (USpatial), SharedGeo was pleased to be able help organize the Minneapolis OSGeo Community Sprint, which was held May 14-17, 2019, at the University of Minnesota. Developed under the guidance of Steve Lime, Kari Guerts and Howard Butler, the event brought together 40 open source programmers from around the world for four days of collaboration and code improvement of OSGeo projects. Although participants were expected to pay for travel and lodging, meals and entertainments were covered by sponsorship donations from 13 organizations. Prudent money management by the event leads also meant that over $3,000 was sent on to OSGeo for support of the 2020 Community Sprint in Athens, Greece. From all reports, the event was highly successful in terms of software improvement and creation of collaborative connections.

Team Spatial and SharedGeo Partner to Install Nation’s Largest Urban ELM Project

April 19, 2019 by central No Comments


Working in close partnership with Atlanta based geospatial firm Team Spatial, SharedGeo has been integral to implementing a comprehensive emergency response trail marking system covering 100’s of miles of urban recreational trails in Cobb County, Georgia. The combination of SharedGeo’s Emergency Location Marker (ELM) system and Team Spatial’s efforts to enhance location information available in E911 dispatch and responder mobile data terminals has led to the county being recognized for innovation and improved trail safety. The items below provide expanded details of this story: