TSPI - National Geospatial-Intelligence Agency

The ellipsoids consist of a blue outer circle and a white inner circle. They can vary in two ways, the width of the inner circle (20, 40, 60, or 80% of the width of the outer circle) and the width of the outer circle (20, 40, 60, or 80% of the height of the outer circle; see Olsson and Poom (2005) for more details). ................
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