ABSTRACT
In the days of analogue recording the maximum dynamic range of seismic recording instruments was in the range 20-25 dB. The early digital recording systems used a fixed gain with about 80 dB of total gain retention. Floatingpoint digital recording systems give up to 100 dB amplitude retention.1 Keeping large variations in signal gain is essential for relative amplitude seismic records and this is the basis of bright spot analysis and high resolution site surveys.
