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

由于高温体的研究成功，使磁仪的实际应用成为现实。

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

摘要重为重位的二阶数，可以通过星仪进行观测。