Overview
Assignment 6 (15 points)
- Considerananalog280-Hzsinusoidalsignal.Ifitwassampledata4-ms interval, what is the alias frequency?
- Atwhatfrequencywoulda210Hzsignalberecordedbyadigital recording system with a sampling rate of 130 Hz?
- Sketchthespectrumyouwouldexpectfromseismogramsrecordedunder the following circumstances. Label the axes.A noise study reveals a generally white background of−6
StudyLectures17&15
TheamplitudesinQ3haveabroadrange.Theverticalaxisdoesnot
need to draw to scale. See L15 for “How to determine the frequency band of a signal”. Below is another example.
amplitude3x10 period range 4-11s. Teleseismic body waves have typical amplitude
, plus microseismic noise of amplitude 10 3x10−4 ms−1 and frequency 0.5-10 Hz; surface waves have typical
Note:
−s
ms
amplitude 5x10−2 ms−1 and period 10-100 s.
−3 −1
ms in the