We consider the analysis of mesospheric neutral air density fluctuations caused by turbulent eddy motions as measured by rocket borne ionization gauges. After shortly reviewing the so far standard Fourier-approach we introduce wavelets as a suitable tool to derive spectral information of the data both as a function of spatial scale and altitude. Applying both techniques to a data set obtained during a recent sounding rocket campaign we show that both methods yield consistent results, however, the wavelet technique yields additional information on the actual vertical extent of the observed turbulent structures.