Integrated Frequency Counter for Multidimensional Seismometric System

We present an integrated frequency counter developed for a multidimensional seismometric system. The aim of the counter is to accurately measure 600 MHz signal from laser gyroscopes and distinguish small frequency changes related to vibrations of the ground surface. The design is implemented in a Kintex-7 field programmable gate array (FPGA) device manufactured by AMD Xilinx. Four parallel measurement channels are designed that combine timestamping and interpolation methods. According to test results the counter is able to measure signals of up to 1 GHz frequency without prescaling and with 9 significant digits in a 1 ms time gate.