Abstract: In order to study the signal generation and signal processing methods of the rotational accelerometer
gravity gradient instrument，a semi-physical simulation system for the gravity gradient instrument is designed．
First，the gravity gradient anomaly caused by an anomalous body in the ground is calculated according to the
measurement principle of the gravity gradient instrument． Using the output formula of the accelerometer，the 12
accelerometers’output signals of the full tensor gravity gradient instrument are simulated by LabVIEW． The
simulation signal is demodulated to obtain the full tensor gravity gradient value． A single disc is taken as an
example for semi-physical simulation． After the acceleration signal generated by computer A passes through the
hardware circuit，the median filtering and demodulation of the conditioned accelerometer signal by computer B
will obtain the abnormal value of gravity gradient with an accuracy of 100E． The design of this simulation system
can demodulate the gravitational gradient of the full tensor，which breaks through the limitation of demodulating
single disc signal． The introduced semi-physical simulation increases the reliability of the algorithm and the
credibility of the simulation． The physical manufacturing has reference significance．

Key words: instrumentation technology, semi-physical simulation, LabVIEW software, accelerometer,
gravity gradiometer