 |
IntroductionThe LEAP, standing for Low-frequency EArthquake Precursor, is a micro-satellite being developed at NCKU, Taiwan, with the mission objective of detecting, recording and downloading Ultra Low frequency (ULF) signals due to earthquake from space. It employs a gravity gradient boom for the installation of payload and stabilization of the satellite. On the tip of the boom, a search coil is used to detect low-frequency wave possibly induced by geomagnetic anomaly. In addition to low-frequency signal detection, the LEAP microsatellite features three payloads including a 2.4 GHz data communication transmitter, GPS receiver, and MEMS based digital sun sensor. |
Earthquake Precursor ObservationAccording to IEEE Spectrum December 2005, ELF magnetic field disturbances caused by Earthquakes can be sensed by satellite observation. Rocks cracking before Earthquakes cause positive charge to flow up toward surface. The flow of charge leads to electromagnetic disturbances that can be detected at the surface and even space. Evidences to support the theory include the Spitake Armenia 6.9-magnitude Earthquake in 1988, the Guam 8.0-magnitude Earthquake in 1993, Loma Prieta 7.1-magnitude Earthquake in 1989 and Chi-Chi 7.9-magnitude Earthquake in 1999. Strong signals were sent out to disturb the magnetic field around two weeks before Earthquakes. The similar missions in the world include DEMETER, a French satellite project and QuakeSat, a cube satellite developed by Stanford University. Comparing to above two satellite projects, the LEAP satellite project main payload measures magnetic field in ULF region, which is lower than VLF and ELF regions. This gives significant values to LEAP satellite project. |
