United States · 1930-2026
Gladys West
Pronunciation: GLAD-is WEST
An American mathematician whose geodetic models and satellite-data analysis contributed to the precision foundations used by GPS.
United States government records, professional recognition, and interviews document West’s geodesy and satellite-data work.
6-8, 9-12, College
The person and the work
Biography
Gladys West studied mathematics and began work at the Naval Proving Ground in Dahlgren, Virginia. She became one of the small number of Black women doing high-level mathematical and computing work there.
West processed satellite observations and developed increasingly refined models of Earth’s shape. Accurate geodetic reference models are essential for locating positions from satellite signals.
Mathematical contribution
What this hero added or preserved
Modeling Earth’s shape
West worked on mathematical models that account for Earth’s irregular, slightly flattened shape rather than treating it as a perfect sphere.
Satellite data and computation
She used large sets of observations and computer calculations to improve geodetic estimates.
Why this matters
The larger lesson
A map coordinate is only useful when the reference model is accurate. Tiny modeling errors can become significant location errors over large distances.
Place the work in time
Timeline
- 1956
Begins work at Dahlgren
West joins the Naval Proving Ground as a mathematician.
- 1970s-1980s
Satellite geodesy work advances
She develops and refines models using satellite observations and computer processing.
- 17 January 2026
A pioneering life closes
West dies at age 95 after her geodetic work had gained broad public recognition.
Key idea
A model can be refined with data
Start with an approximate shape, compare predicted measurements with observations, then adjust parameters to reduce error.
A best-fit ellipsoid approximates Earth more accurately than a perfect sphere for many positioning calculations.
Try it yourself
Measure model error
A model predicts 1,002.4 meters while a measured reference is 1,000 meters. Find the absolute and percent error.
- Subtract the reference from the prediction and take the absolute value.
- Divide the absolute error by the reference.
- Multiply by 100 percent.
Show the answer
Absolute error is 2.4 meters; percent error is 0.24%.
Math at work
Modern navigation rests on geodesy
GPS receivers depend on satellite timing, orbital information, coordinate systems, and a mathematical model of Earth.
Keep curiosity alive
A little-known fact
West’s contribution became widely known late in her life, long after the underlying work had entered everyday navigation technology.
GPS is produced by satellites alone.
Useful positioning also depends on mathematical Earth models, timing, orbital calculations, coordinate systems, and correction methods.
Keep exploring
Connected learning paths
Related math terms
- Geodesy
- Ellipsoid
- Percent error