Аннотация:Spark-generated spherical N-waves in air are measured by means of the Mach-Zehnder interferometer. A thin laser beam with sub-millimeter cross-section is used to obtain the highest time resolution. The light interference pattern is registered by a photodiode connected to a 10 MHz wideband amplifier. The inverse Abel transform is applied to the phase signal of the interferometer to reconstruct the pressure waveform. The peak positive pressure of 3000 Pa is obtained at the distance 10 cm from the source. It is shown that for the realized experimental setup a time resolution of 0.4 μs is reached. This resolution is 6 times better than the time resolution of condenser microphones (2.5 μs for the Brüel & Kjær 1/8 in.). The experimental waveforms measured at distances up to 100 cm are compared with the results of numerical modeling based on the generalized Burgers equation. The experimental waveform measured at 10 cm is set as a starter waveform for the numerical model. The theoretical waveforms are found to be in a good agreement with the measurements for all propagation distances with less than 5% difference for the peak positive pressure. [Work supported by PICS RFBR 10-02-91062/CNRS 5603, RFBR grant 12-02-31830-mola, the President of Russia MK-5895.2013.2 grants and by LabEx CeLyA ANR-10-LABX-60 and SIMMIC ANR-2010-BLAN-0905-03].