A SEISMIC EXPERIMENT (a) I will need geophones that are able to receive 500 Hz Explanation: If vertical resolution is taken as l/4, then vertical resolution can also be expressed as V / (4 x dominant f) If we substitute V=2000 m/s, f = 500 Hz. (b) If we make (Nyquist frequency) Nf= 500 Hz (from answer above), then 500 Hz = 1/(2 x Sampling interval). When we solve this equation the sampling interval = 0.001 s or 1 ms. In other words, we must sample the maximum frequency twice per wavelength, or 1000 times per second. (c) I choose to make my Nyquist frequency = 500 Hz. (d) From the exercise on CMP's I saw that when SP spacing = twice the CMP spacing , the fold will be equal to 1/2 the number of geophones. In this case, 3 m per 12 CMP gives a CMP spacing of 0.25 m. From the first statement in this answer, given that we have 24 geophones and that the desired maximum fold is 12, the shotpoint spacing must equal twice the CMP spacing, i.e. 0.5 m (e) In this special case, the shotpoint spacing is four times the CMP spacing, so the maximum fold is 12. Please see the explanation of the answers to the homework dealing with CMP fold.