## 1 Introduction  
The need for high-resolution seismic imaging has increased over the last three decades to solve shallow geological, engineering, and environmental problems in addition to generating a better velocity model for static corrections. Shallow geophysical applications require the investigation of the subsurface velocity model for depths less than 300 m. This shallow-depth and high-resolution subsurface investigation require acquisition with high-fold and densely spaced receivers. The recording of high-fold and densely spaced receivers' seismic data with traditional acquisition techniques is highly time consuming and requires labor for receiver planting and cable moving, which is a major obstacle in shallow applications of the seismic method. The shallow seismic velocity model is widely used for engineering and geological applications [1, 2, 3, 4, 5, 6]. In deep seismic applications, the shallow velocity model still required for the static corrections. The static corrections are associated with seismic reflection and refraction methods, where it is normally applied to remove the effect of the surface topography, weathering, and sub-weathering layers from the recorded seismic data [7]. Static corrections are defined by [8] as \"Corrections applied to seismic data to compensate for the effects of variations in elevation, near-surface low-velocity-layer (weathering) thickness, weathering velocity, and/or reference to a datum\". Static corrections are usually required for land and transition seismic surveys, however, for most marine surveys, static corrections are not required [7]. Developing shallow velocity models for various applications started in the early days of seismic surveys and continued until recently, where new approaches and techniques have been introduced and published [9; 10; 11; 12; 13; 14]. The importance of finding an accurate shallow-velocity model is very clear, for example, in static corrections, where the effect of ignoring or using wrong static corrections on deep reflectors could be severe. This effect is shown as discontinuity and/or misplacing in deep reflectors [15; 16; 17; 18; 19; 20; 21; 22; 23; 24]. A key input for calculating static corrections is an accurate near-surface velocity model, which includes a description of the thickness, velocities, and variations along the line of the near-surface layers. The shallow-depth velocity model can be found using several approaches such as;  
* Uphole surveys. It is used to obtain near-surface information at specific points along the survey profile. The offset between boreholes is ranging between a few hundred meters to several km depending on the survey site and complexity of the near-surface model. The depth of the borehole is ranging between tens to hundreds of meters, where the borehole should reach the bottom of the weathering and sub-weathering zones [7; 25]. The disadvantages of this approach are that the obtained information is limited to the borehole and the area around it as well as the cost and time required to complete the drilling and up-hole surveys. The velocity model between boreholes is an estimate and obtained by interpolation. * Refraction surveys. It is used for many decades to procure the near-surface velocity models [1; 3; 4; 5; 6; 14]. The refraction method only works if the velocity increases with depth, however, it is not appropriate in areas with high near-surface velocities such as permafrost. Many techniques are used to model refraction surveys such as the intercept time method [26], ABC method [27], Plus-minus method [28], and Generalized Reciprocal method [29]. However, the most used method is the first-arrival travel-time inversion [27]. The tomograms generated from the first-arrival travel-time inversion show the velocity distribution in both horizontal and vertical dimensions, which can be used to calculate the values of the static corrections. The accuracy of the traveltime tomograms depends on the receiver intervals.