PROPOSED STANDARDS FOR SEISMIC AMPLIFIERS . . . AND WHAT THEY MEAN TO FIELD RECORDS

Abstract

Seismic amplifier performance may be categorized broadly into AGC action, filtering, and distortion (including noise). Eight specifications can define the characteristics of each as follows: AGC— 1. Steady‐state AGC including “burst‐out”, 2. AGC control vs frequency, 3. Dynamic AGC action, 4. AGC distortion effects; Filtering— 5. Amplitude response, 6. Phase response; Noise and 7. Pre‐filter distortion; Distortion—8. Internal amplifier noise. These eight specifications allow a user to predict, and consequently allow for, amplifier action—both desirable and deleterious—in obtaining field records. The author proposes that these specifications, coupled with the usual “external” specifications, be considered as a starting point for establishing a standardized method of specifying seismic amplifier characteristics similar to the SEG “Standard Methods of Specifying Performance” for magnetic recording.