The best lines up with the geoid.

最理想的情况是与准面相吻合。

And they came up with this equation that describes the geoid's contours in incredible detail.

们提出了这个方程，以令难以置信的细节描述了准面的轮廓。

So little by little, satellites refined our understanding of Earth's exact shape and this underlying geoid.

卫星一点一滴提升了我们对球精确形状及其基础准面的理解。

Their geoid models, helped them track the exact orbits of spacecraft and satellites, in turn, helped them create better maps of Earth.

们的球模型帮助们精确追踪航天器和卫星的轨道，进而助力绘制更精准的球图。