## 5 Numerical Simulation Test
### Land-Streamer Data Sets  
We generated four different land-streamer data sets where the shot and receiver intervals are 0.5 m, 1.0 m, 2.0 m, and 5.0 m, respectively. In standard land-streamer data, the receiver interval should be ranging between 0.5 and 2.0 m. In this simulation, we added the 5.0 m to compare its results with that of the conventional data set (Figure 8c). In the land-streamer data, only receivers at offset \(\leq\) 100 m from the source point are alive and all receivers are located to the right of the shot point. This setup decreased the number of calculated traces relative to the conventional setup, which affect the number of equations in the inversion process. For example, in the case of 1.0 m shot and receiver intervals, the conventional data has 450 shot gathers, each has 450 receivers, hence the number of  
Figure 8: The traveltime tomograms of the conventional synthetic example. A, B, C, and D represent the four local anomalies added to the velocity model. The red- and blue-horizontal lines represent the refractors between the first-second and second-third layers, respectively. (**a–c**) are the 1 m, 2 m, and 5 m source and receiver intervals, respectively.  
calculated traces is 202,500 traces, while the land-streamer data has 350 shot gathers that each has 100 receivers, hence the total number of calculated traces is 35,000.  
Figure 9 shows the traveltime tomograms of the land-streamer simulation after 23 iterations. Here, we used the same inversion parameters as in the conventional setup case, and the minimum RMS error was about 2.3 ms. The maximum penetration depth is 29 m, which is less than the conventional data set. This is expected since the maximum source-receiver offset in the land-streamer data is 100 m while in the conventional data is 450 m.  
The refractor between the first and the second layers is shown in all tomograms (red line in Figure 9), but the shape of the refractor is also affected by the shape of the overburden anomalies. The main advantage of the land-streamer setup, as shown in Figure 9, is the accurate mapping of the four local anomalies. All four local anomalies are shown on the correct position with the correct shape and correct velocity values in the case of source and receiver offsets of 0.5 m, 1.0 m, and 2.0 m, while in the 5.0 m anomalies B, C, and D are correctly shown on the tomogram, while anomaly A is too weak relative to the other three tomograms. This is expected since the shot and receiver interval in the case of Figure 9d is equal to the thickness of the anomaly and half its width. The four local anomalies are  
Figure 9: The traveltime tomograms of the land-streamer synthetic example. A, B, C, and D represents the four local anomalies added to the velocity model. The red-horizontal line represents the refractor between the first and second layers. (**a–d**) are the 0.5 m, 1 m, 2 m, and 5 m source and receiver intervals, respectively.  
shown on the land-streamer tomograms as four separate bodies, which is more accurate than the result of the conventional setup.  
The two synthetic simulations shown in Figures 8 and 9 show that the seismic conventional setup would reach a larger depth relative to the land-streamer setup, however, the land-streamer setup would detect shallow local anomalies better than the conventional setup.