Wavenumber Response of Data Recorded Using Distributed Fibre-optic Systems

Due to their ease of use, relative low cost, and excellent spatial sampling, distributed fibre-optic- based seismic acquisition systems are gaining increased attention, particularly in vertical seismic profile (VSP) surveys. Data recorded using such systems clearly exhibit a radiation pattern effect whose characteristics depend on the effective length of the section of fibre being used for sampling. The use of long gauge lengths results in the attenuation of high frequencies and high wavenumber whereas the use of short gauge lengths results in the attenuation of low frequencies and low wavenumbers. One solution to this problem would be to process data with a variety of different gauge lengths and merge the data at a later time. Unfortunately many of the systems currently available cannot offer this option because the length is fixed either by the hardware or within the initial processing.