With the invention of high-temperature-superconductor, the superconductive magnetic gradiometer be-comes available in application.

由于高温导体的研究成功，导磁梯度仪的际应用成为现。

Gravity gradient is the second order derivative of gravitational potential, which can be observed by satellite gradiometer.

重力梯度为重力位的二阶导数，可以通过星载梯度仪进行观测。