1. Migration Resolution

2. m = L d T T -1
r = [L L] m
0 km
3 km
0 km km
0 km km

3. Rayleigh Resolution  z 4 L L/2 z
Dx = min. separation & distinguishable Dx
 z L 4

4. Fresnel Zone
T/2 L z
 z L 4

5. Horizontal Resolution Formula
For ZO Migration
Intersection of Fresnel Zones
Horiz. Res. = Far-Offset Traces

6. Horizontal Resolution Formula What is width of minimum
For ZO Migration
What is width of minimum
Lateral cut at depth z?
Horiz. Res. = Far-Offset Traces
Intersection of Fresnel Zones

7. Horizontal Resolution Formula For ZO Migration (Farfield)x l
4 L = ~ z L z l 4
Lateral resolution
gets better as L increases,
wavelength decreases, and
depth gets more shallow D x

8. Horizontal Resolution Formula For ZO Migration (Farfield)q q
tan = = L/z ~
Small angle
approx. valid when L>>z l 4 D x q
sin = l 4
= L/z ~ q D x D x l
4 L = ~ z
Goal: Formula for x D

9. Aperture Width is also Function of Layer Dip Angle and Depth

10. Conclusions ..  d(x, ) LSM: ZO Migration:
m = (L L) L d T -1
LSM:
m = L d T
ZO Migration: ..  x
d(x, )
A(x,x’) 
xx’ =
m(x’)
Smear reflections along fat circles
Far-Offset Traces = Better Hor. Res.
Near-Offset Traces = Better Vert. Res.
m = (L L) r T D x l
4 L = ~ z
l/4 = D z .

11. Exercise Create a 6 point scatterer model, with each pair of point
scatterers separated by a wavelength. Generate synthetic ZO
data and migrate it. Determine if the
resolution formula are validated by measuring
the apparent x distance between adjacent point
scatterers in the image. Use mesh to display image. l D x l
2 L = ~ z l
= 100 m
2 km
2 km