Microtremor and surface wave explorations have been widely applied for geotechnical investigations to estimate the S-wave velocity profile in the last decades. The estimated S-wave velocity profile provides essential information for site characterization. Since the amplitude of the surface wave is much larger than that of the body waves in microtremors and excited vibrations by surface artificial forces, practitioners easily adopt these methods to various geotechnical problems. However, we need to solve an inverse problem with the observed phase velocity of the surface waves to estimate the S-wave velocity profile. Thus, the acquisition of high-quality data is the most critical part. To ensure the data quality and the corresponding results, ISO 24057:2022, array measurement of microtremors to estimate shear wave velocity profile, was developed in 2022. The document specifies appropriate equipment, procedures, data analysis, and reporting for the array measurement of microtremors as a passive geotechnical survey. Note that this standard does not always work for any geological conditions, and this standard describes the data analysis based on the fundamental mode of the Rayleigh waves and excludes the contribution of the higher modes. Since we cannot control the frequency contents in ambient noises, the frequency range with the high power may be limited in the microtremor explorations. In this situation, surface wave exploration using surface waves excited by a sledgehammer can supplement this shortcoming. Combining the two results, we can estimate the S-wave velocity profile from shallow to deep subsurface. Therefore, we are developing a new ISO standard for surface wave explorations by following the microtremor exploration. We expect that the standardization of the two methods enhances the quality of the estimated S-wave velocity profile. Accordingly, non-destructive and cost-effective investigations will be widely accepted in the world.