The World Magnetic Model

The following resources detail the history and ongoing development of the World Magnetic Model.

  • NGA overview. NGA. The official website for the National Geospatial-Intelligence Agency.
  • World Magnetic Model technical overview. NOAA / NCEI. Provides a detailed overview of geomagnetic forces and important considerations for creating the WMM.
  • World Magnetic Model video overview. COLABS Colorado. Provides an approachable overview of how the WMM is created and what applications it informs.
  • World Magnetic Model summary. British Geological Survey (BGS). Provides an approachable summary of the World Magnetic Model purpose and development process.
  • World Magnetic Model applications. NOAA / NCEI. Describes common applications of the World Magnetic Model, including uses for navigation and within consumer electronics.
  • 2020 World Magnetic Model Report. NOAA / BGS. Contains a complete report of the World Magnetic Model.
  • World Magnetic Model update. Nature International Journal of Science. Describes the erratic motion of the north magnetic pole that necessitated an out-of-cycle update to the WMM.
  • World Magnetic Model Mil-Spec. NGA. Details the specifications required for the World Magnetic Model.
  • World Magnetic Model data collection procurement notice. A public notice indicating that the National Geospatial-Intelligence Agency (NGA), in accordance with FAR Subpart 5.404 release of long-range acquisition estimates, is planning the procurement of a World Magnetic Model (WMM) global magnetic field data collection capability and is providing public notice to assist industry in its planning to facilitate meeting the acquisition requirements.

Technology

The following resources detail technologies that are used to collect data for the World Magnetic Model or may be potential alternatives. A resource with guidance for on technology readiness definitions is also included.

Potential solution areas

The following examples demonstrate a range of solutions that could be submitted. Note that this list is illustrative, and is not a comprehensive list of all potential solution areas

  • Spaceborne. A solution that integrates one or more small or large satellites, or proposes adding instrumentation to an unrelated mission as a hosted payload.
  • Terrestrial. A solution that indicates how the existing ground observatories or mobile technology could be leveraged.
  • Aerial. A solution that proposes drones, balloons, or other aerial technology.
  • Data analysis. A solution that proposes how available data sources could be utilized through new advancement in data modeling and processing techniques. (Reminder: the Challenge does not ask solvers for alternate methods of creating the WMM; it asks solvers to identify new data sources to inform the current WMM production.)

Target performance metrics

MagQuest seeks solutions that will capture data sufficient to produce the World Magnetic Model. The performance specifications below represent thresholds for solutions to consider.

These Phase 3 target performance metrics are an updated version of the information provided in previous phases.

Space-based measurement targets

Mission objectives Determine the structure of the Earth’s magnetic field for navigational, and attitude and heading applications
Measurement objectives Measure Earth’s main magnetic field strength and direction
Measurement targets Measure magnetic field with absolute and vector accuracy of 5 nT or better, noise level of 5 nT (1σ) or lower, 1 sec time resolution
Instrument targets
  1. Vector magnetometer
    Vector component accuracy 5 nT or better; noise level (1σ) 5 nT or lower; dynamic range 15,000– 70,000 nT; drift less than 1 nT/year; 1s sampling resolution
  2. Scalar magnetometer (if needed for a calibration source)
    Accuracy 5 nT or better, noise level (1σ) 5 nT or lower; dynamic range 15,000 – 70,000 nT; 1s sampling resolution
Mission targets For Space: Magnetometer axis orientation knowledge of 10 arc-sec or better; spacecraft magnetically clean and/or magnetometer boom to meet measurement error budget targets; data latency 3 months or less

 

Other significant targets

  1. Spacecraft orbits
    • Altitude: within 400-800 km
    • Inclination: within 81° – 90° degrees
    • Measurements taken at local night (although not exclusively)
  2. Mission operations
    • Full Operational Capability (FOC) by 2027
    • Runs through 2047 (20-year program)
    • Continuous data collection without gaps of more than 1 month in a 12-month period.

Ground-based measurement targets

Table 1: Performance metrics currently met by INTERMAGNET observatories

1 Measurement positioning and timing accuracy Preferably provided by dual frequency GPS receiver
2 Measurement accuracy 5 nT (In geographic frame, after accounting for orientation error, crustal biases, biases due to temperature effects, mechanical noise, and any other systematic noise source)
3 Measurement resolution 0.1 nT
4 Measurement sampling rate At least one measurement per minute
5 Measurement range -70,000 to 70,000 nT
6 Measurement time span Continuous measurement solutions

Comments: target #2 is met by observatories meeting INTERMAGNET requirements, provided there is at least a one year overlap with a space-based solution to determine crustal biases. Any potential MagQuest solution that does not contain a space-based component will need to include a solution for crustal bias information, or provide justification it is not necessary.

Table 2: Potential solutions to improve data by INTERMAGNET stations

A Measurement location Add N1 observatories to the INTERMAGNET network
B Measurement data latency Improve data latency at N2</sup INTERMAGNET observatories

Comments: for Potential Solution B, INTERMAGNET could meet the WMM requirements without adding any additional sites if every current ground station provided Quasi-Definitive data in less than one year. Ideally the stations would provide data as quickly as possible. There are currently only a small subset of INTERMAGNET observatories (~59) that meet the one year data latency target.