Acoustic travel time tomography is presented as an experimental technique for remote monitoring of spatially averaged meteorological quantities, such as the virtual temperature and the horizontal wind speed. This ground based remote sensing technique uses the nearly horizontal propagation of sound waves in the atmospheric surface layer. Here the acoustic travel time tomography was applied by measuring the travel time at defined propagation paths between several sound sources and receivers. The resulting sound speed was used to obtain estimates of the meteorological parameters. Several measuring campaigns were carried out to compare the acoustically derived data with conventional systems. The results of a cross-validation during a field experiment in autumn 2000 are presented, where receivers at different heights above the ground were used. These observations demonstrated that (1) the accuracy of the acoustic tomography is comparable with in-situ measurements, and (2) the temperature was from time to time significantly overestimated by the standard sensors, probably due to the radiation influence.