Unformatted text preview: The plus-minus method Assumptions and approximations 1. The relief on the refractor must be small compared to the depth 2. Geometric relations assume a small refractor dip (dip < 10 deg) 3. Refractor assumed to be planar between the two points of emergence to a given geophone (ie between C and E) So that ∆ T D is equal when shooting from both sides...
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- Spring '09
- Light, Refracting telescope, Applied Geophysics, plus-minus method, delay time ∆TD