In recent years, the acoustic technology for landmine detection has demonstrated success in field testing. Acoustic-to-seismic responses of buried landmines are exploited for locating the targets. Field experiments have demonstrated that different burial conditions and different landmines show different linear frequency responses. Therefore, the landmine detection system uses broad-band excitations. Until now, the research work for acoustic landmine detection has primarily focused on demonstrating a high probability of detection and low false alarm rate through systematic field experiments, such as blind field tests, especially for anti-tank mines. However, the speed of detection has not yet been shown to meet operational requirements. In designing a moving platform, one must know how fast an acoustic detector can acquire high-quality data, and what factors limit increased moving speed. Based upon field test results, this paper investigates the relationship between the bandwidth of the pseudo-random excitation, frequency resolution of linear response measurements, speckle noise, and reliable moving speeds of acoustic/seismic sensors.