Receiver Decimation and Impact on DAS VSP Data Processing Quality

Summary DAS, FiberVSP. Redundancy, Decimation, Aliasing, Apparent velocity, Median, Mean, Stack, Sinc function Because of the small (~ 1 m) depth interval between channels of distributed acoustic sensing (DAS) vertical seismic profile (VSP) datasets, the storage and computing power of conventional workstations can be quickly overwhelmed. In practice, channel decimation on DAS data has been applied to reduce data volume. We investigate four decimation methods and their impact on seismic data processing quality based on a recently acquired Walkaway (WAW) FiberVSP™ service dataset. First, we examine the simple direct trace decimation without spatial filtering and secondly, decimation with anti-alias filtering to mitigate noise. Third is mean stacking and lastly is median stacking—both of which can produce high quality decimated seismic data and are preferred methods for channel decimation when considering the attenuation of random noise.